update systemd & dbus dependencies

Update the outdated systemd and dbus dependencies which are now provided
as go modules.  This will further tighten our dependencies and releases
and pave the way for the upcoming auto-update feature.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

16 files changed, 3683 insertions, 0 deletions

diff --git a/vendor/github.com/coreos/go-systemd/v22/LICENSE b/vendor/github.com/coreos/go-systemd/v22/LICENSE
new file mode 100644
index 000000000..37ec93a14
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/LICENSE
@@ -0,0 +1,191 @@
+Apache License
+Version 2.0, January 2004
+http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+"License" shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+"Licensor" shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+"Legal Entity" shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, "control" means (i) the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the
+outstanding shares, or (iii) beneficial ownership of such entity.
+
+"You" (or "Your") shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+"Source" form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+"Object" form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+"Work" shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+"Derivative Works" shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+"Contribution" shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+"submitted" means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as "Not a Contribution."
+
+"Contributor" shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+2. Grant of Copyright License.
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+3. Grant of Patent License.
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+4. Redistribution.
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+If the Work includes a "NOTICE" text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+5. Submission of Contributions.
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+6. Trademarks.
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty.
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+8. Limitation of Liability.
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability.
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets "[]" replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same "printed page" as the copyright notice for easier identification within
+third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/coreos/go-systemd/v22/NOTICE b/vendor/github.com/coreos/go-systemd/v22/NOTICE
new file mode 100644
index 000000000..23a0ada2f
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/NOTICE
@@ -0,0 +1,5 @@
+CoreOS Project
+Copyright 2018 CoreOS, Inc
+
+This product includes software developed at CoreOS, Inc.
+(http://www.coreos.com/).
diff --git a/vendor/github.com/coreos/go-systemd/v22/activation/files.go b/vendor/github.com/coreos/go-systemd/v22/activation/files.go
new file mode 100644
index 000000000..29dd18def
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/activation/files.go
@@ -0,0 +1,67 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package activation implements primitives for systemd socket activation.
+package activation
+
+import (
+	"os"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+const (
+	// listenFdsStart corresponds to `SD_LISTEN_FDS_START`.
+	listenFdsStart = 3
+)
+
+// Files returns a slice containing a `os.File` object for each
+// file descriptor passed to this process via systemd fd-passing protocol.
+//
+// The order of the file descriptors is preserved in the returned slice.
+// `unsetEnv` is typically set to `true` in order to avoid clashes in
+// fd usage and to avoid leaking environment flags to child processes.
+func Files(unsetEnv bool) []*os.File {
+	if unsetEnv {
+		defer os.Unsetenv("LISTEN_PID")
+		defer os.Unsetenv("LISTEN_FDS")
+		defer os.Unsetenv("LISTEN_FDNAMES")
+	}
+
+	pid, err := strconv.Atoi(os.Getenv("LISTEN_PID"))
+	if err != nil || pid != os.Getpid() {
+		return nil
+	}
+
+	nfds, err := strconv.Atoi(os.Getenv("LISTEN_FDS"))
+	if err != nil || nfds == 0 {
+		return nil
+	}
+
+	names := strings.Split(os.Getenv("LISTEN_FDNAMES"), ":")
+
+	files := make([]*os.File, 0, nfds)
+	for fd := listenFdsStart; fd < listenFdsStart+nfds; fd++ {
+		syscall.CloseOnExec(fd)
+		name := "LISTEN_FD_" + strconv.Itoa(fd)
+		offset := fd - listenFdsStart
+		if offset < len(names) && len(names[offset]) > 0 {
+			name = names[offset]
+		}
+		files = append(files, os.NewFile(uintptr(fd), name))
+	}
+
+	return files
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/activation/listeners.go b/vendor/github.com/coreos/go-systemd/v22/activation/listeners.go
new file mode 100644
index 000000000..3dbe2b087
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/activation/listeners.go
@@ -0,0 +1,103 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package activation
+
+import (
+	"crypto/tls"
+	"net"
+)
+
+// Listeners returns a slice containing a net.Listener for each matching socket type
+// passed to this process.
+//
+// The order of the file descriptors is preserved in the returned slice.
+// Nil values are used to fill any gaps. For example if systemd were to return file descriptors
+// corresponding with "udp, tcp, tcp", then the slice would contain {nil, net.Listener, net.Listener}
+func Listeners() ([]net.Listener, error) {
+	files := Files(true)
+	listeners := make([]net.Listener, len(files))
+
+	for i, f := range files {
+		if pc, err := net.FileListener(f); err == nil {
+			listeners[i] = pc
+			f.Close()
+		}
+	}
+	return listeners, nil
+}
+
+// ListenersWithNames maps a listener name to a set of net.Listener instances.
+func ListenersWithNames() (map[string][]net.Listener, error) {
+	files := Files(true)
+	listeners := map[string][]net.Listener{}
+
+	for _, f := range files {
+		if pc, err := net.FileListener(f); err == nil {
+			current, ok := listeners[f.Name()]
+			if !ok {
+				listeners[f.Name()] = []net.Listener{pc}
+			} else {
+				listeners[f.Name()] = append(current, pc)
+			}
+			f.Close()
+		}
+	}
+	return listeners, nil
+}
+
+// TLSListeners returns a slice containing a net.listener for each matching TCP socket type
+// passed to this process.
+// It uses default Listeners func and forces TCP sockets handlers to use TLS based on tlsConfig.
+func TLSListeners(tlsConfig *tls.Config) ([]net.Listener, error) {
+	listeners, err := Listeners()
+
+	if listeners == nil || err != nil {
+		return nil, err
+	}
+
+	if tlsConfig != nil {
+		for i, l := range listeners {
+			// Activate TLS only for TCP sockets
+			if l.Addr().Network() == "tcp" {
+				listeners[i] = tls.NewListener(l, tlsConfig)
+			}
+		}
+	}
+
+	return listeners, err
+}
+
+// TLSListenersWithNames maps a listener name to a net.Listener with
+// the associated TLS configuration.
+func TLSListenersWithNames(tlsConfig *tls.Config) (map[string][]net.Listener, error) {
+	listeners, err := ListenersWithNames()
+
+	if listeners == nil || err != nil {
+		return nil, err
+	}
+
+	if tlsConfig != nil {
+		for _, ll := range listeners {
+			// Activate TLS only for TCP sockets
+			for i, l := range ll {
+				if l.Addr().Network() == "tcp" {
+					ll[i] = tls.NewListener(l, tlsConfig)
+				}
+			}
+		}
+	}
+
+	return listeners, err
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/activation/packetconns.go b/vendor/github.com/coreos/go-systemd/v22/activation/packetconns.go
new file mode 100644
index 000000000..a97206785
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/activation/packetconns.go
@@ -0,0 +1,38 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package activation
+
+import (
+	"net"
+)
+
+// PacketConns returns a slice containing a net.PacketConn for each matching socket type
+// passed to this process.
+//
+// The order of the file descriptors is preserved in the returned slice.
+// Nil values are used to fill any gaps. For example if systemd were to return file descriptors
+// corresponding with "udp, tcp, udp", then the slice would contain {net.PacketConn, nil, net.PacketConn}
+func PacketConns() ([]net.PacketConn, error) {
+	files := Files(true)
+	conns := make([]net.PacketConn, len(files))
+
+	for i, f := range files {
+		if pc, err := net.FilePacketConn(f); err == nil {
+			conns[i] = pc
+			f.Close()
+		}
+	}
+	return conns, nil
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/dbus/dbus.go b/vendor/github.com/coreos/go-systemd/v22/dbus/dbus.go
new file mode 100644
index 000000000..91584a166
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/dbus/dbus.go
@@ -0,0 +1,240 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Integration with the systemd D-Bus API.  See http://www.freedesktop.org/wiki/Software/systemd/dbus/
+package dbus
+
+import (
+	"encoding/hex"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/godbus/dbus/v5"
+)
+
+const (
+	alpha        = `abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ`
+	num          = `0123456789`
+	alphanum     = alpha + num
+	signalBuffer = 100
+)
+
+// needsEscape checks whether a byte in a potential dbus ObjectPath needs to be escaped
+func needsEscape(i int, b byte) bool {
+	// Escape everything that is not a-z-A-Z-0-9
+	// Also escape 0-9 if it's the first character
+	return strings.IndexByte(alphanum, b) == -1 ||
+		(i == 0 && strings.IndexByte(num, b) != -1)
+}
+
+// PathBusEscape sanitizes a constituent string of a dbus ObjectPath using the
+// rules that systemd uses for serializing special characters.
+func PathBusEscape(path string) string {
+	// Special case the empty string
+	if len(path) == 0 {
+		return "_"
+	}
+	n := []byte{}
+	for i := 0; i < len(path); i++ {
+		c := path[i]
+		if needsEscape(i, c) {
+			e := fmt.Sprintf("_%x", c)
+			n = append(n, []byte(e)...)
+		} else {
+			n = append(n, c)
+		}
+	}
+	return string(n)
+}
+
+// pathBusUnescape is the inverse of PathBusEscape.
+func pathBusUnescape(path string) string {
+	if path == "_" {
+		return ""
+	}
+	n := []byte{}
+	for i := 0; i < len(path); i++ {
+		c := path[i]
+		if c == '_' && i+2 < len(path) {
+			res, err := hex.DecodeString(path[i+1 : i+3])
+			if err == nil {
+				n = append(n, res...)
+			}
+			i += 2
+		} else {
+			n = append(n, c)
+		}
+	}
+	return string(n)
+}
+
+// Conn is a connection to systemd's dbus endpoint.
+type Conn struct {
+	// sysconn/sysobj are only used to call dbus methods
+	sysconn *dbus.Conn
+	sysobj  dbus.BusObject
+
+	// sigconn/sigobj are only used to receive dbus signals
+	sigconn *dbus.Conn
+	sigobj  dbus.BusObject
+
+	jobListener struct {
+		jobs map[dbus.ObjectPath]chan<- string
+		sync.Mutex
+	}
+	subStateSubscriber struct {
+		updateCh chan<- *SubStateUpdate
+		errCh    chan<- error
+		sync.Mutex
+		ignore      map[dbus.ObjectPath]int64
+		cleanIgnore int64
+	}
+	propertiesSubscriber struct {
+		updateCh chan<- *PropertiesUpdate
+		errCh    chan<- error
+		sync.Mutex
+	}
+}
+
+// New establishes a connection to any available bus and authenticates.
+// Callers should call Close() when done with the connection.
+func New() (*Conn, error) {
+	conn, err := NewSystemConnection()
+	if err != nil && os.Geteuid() == 0 {
+		return NewSystemdConnection()
+	}
+	return conn, err
+}
+
+// NewSystemConnection establishes a connection to the system bus and authenticates.
+// Callers should call Close() when done with the connection
+func NewSystemConnection() (*Conn, error) {
+	return NewConnection(func() (*dbus.Conn, error) {
+		return dbusAuthHelloConnection(dbus.SystemBusPrivate)
+	})
+}
+
+// NewUserConnection establishes a connection to the session bus and
+// authenticates. This can be used to connect to systemd user instances.
+// Callers should call Close() when done with the connection.
+func NewUserConnection() (*Conn, error) {
+	return NewConnection(func() (*dbus.Conn, error) {
+		return dbusAuthHelloConnection(dbus.SessionBusPrivate)
+	})
+}
+
+// NewSystemdConnection establishes a private, direct connection to systemd.
+// This can be used for communicating with systemd without a dbus daemon.
+// Callers should call Close() when done with the connection.
+func NewSystemdConnection() (*Conn, error) {
+	return NewConnection(func() (*dbus.Conn, error) {
+		// We skip Hello when talking directly to systemd.
+		return dbusAuthConnection(func(opts ...dbus.ConnOption) (*dbus.Conn, error) {
+			return dbus.Dial("unix:path=/run/systemd/private")
+		})
+	})
+}
+
+// Close closes an established connection
+func (c *Conn) Close() {
+	c.sysconn.Close()
+	c.sigconn.Close()
+}
+
+// NewConnection establishes a connection to a bus using a caller-supplied function.
+// This allows connecting to remote buses through a user-supplied mechanism.
+// The supplied function may be called multiple times, and should return independent connections.
+// The returned connection must be fully initialised: the org.freedesktop.DBus.Hello call must have succeeded,
+// and any authentication should be handled by the function.
+func NewConnection(dialBus func() (*dbus.Conn, error)) (*Conn, error) {
+	sysconn, err := dialBus()
+	if err != nil {
+		return nil, err
+	}
+
+	sigconn, err := dialBus()
+	if err != nil {
+		sysconn.Close()
+		return nil, err
+	}
+
+	c := &Conn{
+		sysconn: sysconn,
+		sysobj:  systemdObject(sysconn),
+		sigconn: sigconn,
+		sigobj:  systemdObject(sigconn),
+	}
+
+	c.subStateSubscriber.ignore = make(map[dbus.ObjectPath]int64)
+	c.jobListener.jobs = make(map[dbus.ObjectPath]chan<- string)
+
+	// Setup the listeners on jobs so that we can get completions
+	c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
+		"type='signal', interface='org.freedesktop.systemd1.Manager', member='JobRemoved'")
+
+	c.dispatch()
+	return c, nil
+}
+
+// GetManagerProperty returns the value of a property on the org.freedesktop.systemd1.Manager
+// interface. The value is returned in its string representation, as defined at
+// https://developer.gnome.org/glib/unstable/gvariant-text.html
+func (c *Conn) GetManagerProperty(prop string) (string, error) {
+	variant, err := c.sysobj.GetProperty("org.freedesktop.systemd1.Manager." + prop)
+	if err != nil {
+		return "", err
+	}
+	return variant.String(), nil
+}
+
+func dbusAuthConnection(createBus func(opts ...dbus.ConnOption) (*dbus.Conn, error)) (*dbus.Conn, error) {
+	conn, err := createBus()
+	if err != nil {
+		return nil, err
+	}
+
+	// Only use EXTERNAL method, and hardcode the uid (not username)
+	// to avoid a username lookup (which requires a dynamically linked
+	// libc)
+	methods := []dbus.Auth{dbus.AuthExternal(strconv.Itoa(os.Getuid()))}
+
+	err = conn.Auth(methods)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	return conn, nil
+}
+
+func dbusAuthHelloConnection(createBus func(opts ...dbus.ConnOption) (*dbus.Conn, error)) (*dbus.Conn, error) {
+	conn, err := dbusAuthConnection(createBus)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = conn.Hello(); err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	return conn, nil
+}
+
+func systemdObject(conn *dbus.Conn) dbus.BusObject {
+	return conn.Object("org.freedesktop.systemd1", dbus.ObjectPath("/org/freedesktop/systemd1"))
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/dbus/methods.go b/vendor/github.com/coreos/go-systemd/v22/dbus/methods.go
new file mode 100644
index 000000000..e38659d7b
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/dbus/methods.go
@@ -0,0 +1,600 @@
+// Copyright 2015, 2018 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"errors"
+	"fmt"
+	"path"
+	"strconv"
+
+	"github.com/godbus/dbus/v5"
+)
+
+func (c *Conn) jobComplete(signal *dbus.Signal) {
+	var id uint32
+	var job dbus.ObjectPath
+	var unit string
+	var result string
+	dbus.Store(signal.Body, &id, &job, &unit, &result)
+	c.jobListener.Lock()
+	out, ok := c.jobListener.jobs[job]
+	if ok {
+		out <- result
+		delete(c.jobListener.jobs, job)
+	}
+	c.jobListener.Unlock()
+}
+
+func (c *Conn) startJob(ch chan<- string, job string, args ...interface{}) (int, error) {
+	if ch != nil {
+		c.jobListener.Lock()
+		defer c.jobListener.Unlock()
+	}
+
+	var p dbus.ObjectPath
+	err := c.sysobj.Call(job, 0, args...).Store(&p)
+	if err != nil {
+		return 0, err
+	}
+
+	if ch != nil {
+		c.jobListener.jobs[p] = ch
+	}
+
+	// ignore error since 0 is fine if conversion fails
+	jobID, _ := strconv.Atoi(path.Base(string(p)))
+
+	return jobID, nil
+}
+
+// StartUnit enqueues a start job and depending jobs, if any (unless otherwise
+// specified by the mode string).
+//
+// Takes the unit to activate, plus a mode string. The mode needs to be one of
+// replace, fail, isolate, ignore-dependencies, ignore-requirements. If
+// "replace" the call will start the unit and its dependencies, possibly
+// replacing already queued jobs that conflict with this. If "fail" the call
+// will start the unit and its dependencies, but will fail if this would change
+// an already queued job. If "isolate" the call will start the unit in question
+// and terminate all units that aren't dependencies of it. If
+// "ignore-dependencies" it will start a unit but ignore all its dependencies.
+// If "ignore-requirements" it will start a unit but only ignore the
+// requirement dependencies. It is not recommended to make use of the latter
+// two options.
+//
+// If the provided channel is non-nil, a result string will be sent to it upon
+// job completion: one of done, canceled, timeout, failed, dependency, skipped.
+// done indicates successful execution of a job. canceled indicates that a job
+// has been canceled  before it finished execution. timeout indicates that the
+// job timeout was reached. failed indicates that the job failed. dependency
+// indicates that a job this job has been depending on failed and the job hence
+// has been removed too. skipped indicates that a job was skipped because it
+// didn't apply to the units current state.
+//
+// If no error occurs, the ID of the underlying systemd job will be returned. There
+// does exist the possibility for no error to be returned, but for the returned job
+// ID to be 0. In this case, the actual underlying ID is not 0 and this datapoint
+// should not be considered authoritative.
+//
+// If an error does occur, it will be returned to the user alongside a job ID of 0.
+func (c *Conn) StartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.StartUnit", name, mode)
+}
+
+// StopUnit is similar to StartUnit but stops the specified unit rather
+// than starting it.
+func (c *Conn) StopUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.StopUnit", name, mode)
+}
+
+// ReloadUnit reloads a unit.  Reloading is done only if the unit is already running and fails otherwise.
+func (c *Conn) ReloadUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.ReloadUnit", name, mode)
+}
+
+// RestartUnit restarts a service.  If a service is restarted that isn't
+// running it will be started.
+func (c *Conn) RestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.RestartUnit", name, mode)
+}
+
+// TryRestartUnit is like RestartUnit, except that a service that isn't running
+// is not affected by the restart.
+func (c *Conn) TryRestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.TryRestartUnit", name, mode)
+}
+
+// ReloadOrRestartUnit attempts a reload if the unit supports it and use a restart
+// otherwise.
+func (c *Conn) ReloadOrRestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.ReloadOrRestartUnit", name, mode)
+}
+
+// ReloadOrTryRestartUnit attempts a reload if the unit supports it and use a "Try"
+// flavored restart otherwise.
+func (c *Conn) ReloadOrTryRestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.ReloadOrTryRestartUnit", name, mode)
+}
+
+// StartTransientUnit() may be used to create and start a transient unit, which
+// will be released as soon as it is not running or referenced anymore or the
+// system is rebooted. name is the unit name including suffix, and must be
+// unique. mode is the same as in StartUnit(), properties contains properties
+// of the unit.
+func (c *Conn) StartTransientUnit(name string, mode string, properties []Property, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.StartTransientUnit", name, mode, properties, make([]PropertyCollection, 0))
+}
+
+// KillUnit takes the unit name and a UNIX signal number to send.  All of the unit's
+// processes are killed.
+func (c *Conn) KillUnit(name string, signal int32) {
+	c.sysobj.Call("org.freedesktop.systemd1.Manager.KillUnit", 0, name, "all", signal).Store()
+}
+
+// ResetFailedUnit resets the "failed" state of a specific unit.
+func (c *Conn) ResetFailedUnit(name string) error {
+	return c.sysobj.Call("org.freedesktop.systemd1.Manager.ResetFailedUnit", 0, name).Store()
+}
+
+// SystemState returns the systemd state. Equivalent to `systemctl is-system-running`.
+func (c *Conn) SystemState() (*Property, error) {
+	var err error
+	var prop dbus.Variant
+
+	obj := c.sysconn.Object("org.freedesktop.systemd1", "/org/freedesktop/systemd1")
+	err = obj.Call("org.freedesktop.DBus.Properties.Get", 0, "org.freedesktop.systemd1.Manager", "SystemState").Store(&prop)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Property{Name: "SystemState", Value: prop}, nil
+}
+
+// getProperties takes the unit path and returns all of its dbus object properties, for the given dbus interface
+func (c *Conn) getProperties(path dbus.ObjectPath, dbusInterface string) (map[string]interface{}, error) {
+	var err error
+	var props map[string]dbus.Variant
+
+	if !path.IsValid() {
+		return nil, fmt.Errorf("invalid unit name: %v", path)
+	}
+
+	obj := c.sysconn.Object("org.freedesktop.systemd1", path)
+	err = obj.Call("org.freedesktop.DBus.Properties.GetAll", 0, dbusInterface).Store(&props)
+	if err != nil {
+		return nil, err
+	}
+
+	out := make(map[string]interface{}, len(props))
+	for k, v := range props {
+		out[k] = v.Value()
+	}
+
+	return out, nil
+}
+
+// GetUnitProperties takes the (unescaped) unit name and returns all of its dbus object properties.
+func (c *Conn) GetUnitProperties(unit string) (map[string]interface{}, error) {
+	path := unitPath(unit)
+	return c.getProperties(path, "org.freedesktop.systemd1.Unit")
+}
+
+// GetUnitPathProperties takes the (escaped) unit path and returns all of its dbus object properties.
+func (c *Conn) GetUnitPathProperties(path dbus.ObjectPath) (map[string]interface{}, error) {
+	return c.getProperties(path, "org.freedesktop.systemd1.Unit")
+}
+
+// GetAllProperties takes the (unescaped) unit name and returns all of its dbus object properties.
+func (c *Conn) GetAllProperties(unit string) (map[string]interface{}, error) {
+	path := unitPath(unit)
+	return c.getProperties(path, "")
+}
+
+func (c *Conn) getProperty(unit string, dbusInterface string, propertyName string) (*Property, error) {
+	var err error
+	var prop dbus.Variant
+
+	path := unitPath(unit)
+	if !path.IsValid() {
+		return nil, errors.New("invalid unit name: " + unit)
+	}
+
+	obj := c.sysconn.Object("org.freedesktop.systemd1", path)
+	err = obj.Call("org.freedesktop.DBus.Properties.Get", 0, dbusInterface, propertyName).Store(&prop)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Property{Name: propertyName, Value: prop}, nil
+}
+
+func (c *Conn) GetUnitProperty(unit string, propertyName string) (*Property, error) {
+	return c.getProperty(unit, "org.freedesktop.systemd1.Unit", propertyName)
+}
+
+// GetServiceProperty returns property for given service name and property name
+func (c *Conn) GetServiceProperty(service string, propertyName string) (*Property, error) {
+	return c.getProperty(service, "org.freedesktop.systemd1.Service", propertyName)
+}
+
+// GetUnitTypeProperties returns the extra properties for a unit, specific to the unit type.
+// Valid values for unitType: Service, Socket, Target, Device, Mount, Automount, Snapshot, Timer, Swap, Path, Slice, Scope
+// return "dbus.Error: Unknown interface" if the unitType is not the correct type of the unit
+func (c *Conn) GetUnitTypeProperties(unit string, unitType string) (map[string]interface{}, error) {
+	path := unitPath(unit)
+	return c.getProperties(path, "org.freedesktop.systemd1."+unitType)
+}
+
+// SetUnitProperties() may be used to modify certain unit properties at runtime.
+// Not all properties may be changed at runtime, but many resource management
+// settings (primarily those in systemd.cgroup(5)) may. The changes are applied
+// instantly, and stored on disk for future boots, unless runtime is true, in which
+// case the settings only apply until the next reboot. name is the name of the unit
+// to modify. properties are the settings to set, encoded as an array of property
+// name and value pairs.
+func (c *Conn) SetUnitProperties(name string, runtime bool, properties ...Property) error {
+	return c.sysobj.Call("org.freedesktop.systemd1.Manager.SetUnitProperties", 0, name, runtime, properties).Store()
+}
+
+func (c *Conn) GetUnitTypeProperty(unit string, unitType string, propertyName string) (*Property, error) {
+	return c.getProperty(unit, "org.freedesktop.systemd1."+unitType, propertyName)
+}
+
+type UnitStatus struct {
+	Name        string          // The primary unit name as string
+	Description string          // The human readable description string
+	LoadState   string          // The load state (i.e. whether the unit file has been loaded successfully)
+	ActiveState string          // The active state (i.e. whether the unit is currently started or not)
+	SubState    string          // The sub state (a more fine-grained version of the active state that is specific to the unit type, which the active state is not)
+	Followed    string          // A unit that is being followed in its state by this unit, if there is any, otherwise the empty string.
+	Path        dbus.ObjectPath // The unit object path
+	JobId       uint32          // If there is a job queued for the job unit the numeric job id, 0 otherwise
+	JobType     string          // The job type as string
+	JobPath     dbus.ObjectPath // The job object path
+}
+
+type storeFunc func(retvalues ...interface{}) error
+
+func (c *Conn) listUnitsInternal(f storeFunc) ([]UnitStatus, error) {
+	result := make([][]interface{}, 0)
+	err := f(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	status := make([]UnitStatus, len(result))
+	statusInterface := make([]interface{}, len(status))
+	for i := range status {
+		statusInterface[i] = &status[i]
+	}
+
+	err = dbus.Store(resultInterface, statusInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return status, nil
+}
+
+// ListUnits returns an array with all currently loaded units. Note that
+// units may be known by multiple names at the same time, and hence there might
+// be more unit names loaded than actual units behind them.
+// Also note that a unit is only loaded if it is active and/or enabled.
+// Units that are both disabled and inactive will thus not be returned.
+func (c *Conn) ListUnits() ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnits", 0).Store)
+}
+
+// ListUnitsFiltered returns an array with units filtered by state.
+// It takes a list of units' statuses to filter.
+func (c *Conn) ListUnitsFiltered(states []string) ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitsFiltered", 0, states).Store)
+}
+
+// ListUnitsByPatterns returns an array with units.
+// It takes a list of units' statuses and names to filter.
+// Note that units may be known by multiple names at the same time,
+// and hence there might be more unit names loaded than actual units behind them.
+func (c *Conn) ListUnitsByPatterns(states []string, patterns []string) ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitsByPatterns", 0, states, patterns).Store)
+}
+
+// ListUnitsByNames returns an array with units. It takes a list of units'
+// names and returns an UnitStatus array. Comparing to ListUnitsByPatterns
+// method, this method returns statuses even for inactive or non-existing
+// units. Input array should contain exact unit names, but not patterns.
+// Note: Requires systemd v230 or higher
+func (c *Conn) ListUnitsByNames(units []string) ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitsByNames", 0, units).Store)
+}
+
+type UnitFile struct {
+	Path string
+	Type string
+}
+
+func (c *Conn) listUnitFilesInternal(f storeFunc) ([]UnitFile, error) {
+	result := make([][]interface{}, 0)
+	err := f(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	files := make([]UnitFile, len(result))
+	fileInterface := make([]interface{}, len(files))
+	for i := range files {
+		fileInterface[i] = &files[i]
+	}
+
+	err = dbus.Store(resultInterface, fileInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return files, nil
+}
+
+// ListUnitFiles returns an array of all available units on disk.
+func (c *Conn) ListUnitFiles() ([]UnitFile, error) {
+	return c.listUnitFilesInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitFiles", 0).Store)
+}
+
+// ListUnitFilesByPatterns returns an array of all available units on disk matched the patterns.
+func (c *Conn) ListUnitFilesByPatterns(states []string, patterns []string) ([]UnitFile, error) {
+	return c.listUnitFilesInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitFilesByPatterns", 0, states, patterns).Store)
+}
+
+type LinkUnitFileChange EnableUnitFileChange
+
+// LinkUnitFiles() links unit files (that are located outside of the
+// usual unit search paths) into the unit search path.
+//
+// It takes a list of absolute paths to unit files to link and two
+// booleans. The first boolean controls whether the unit shall be
+// enabled for runtime only (true, /run), or persistently (false,
+// /etc).
+// The second controls whether symlinks pointing to other units shall
+// be replaced if necessary.
+//
+// This call returns a list of the changes made. The list consists of
+// structures with three strings: the type of the change (one of symlink
+// or unlink), the file name of the symlink and the destination of the
+// symlink.
+func (c *Conn) LinkUnitFiles(files []string, runtime bool, force bool) ([]LinkUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.LinkUnitFiles", 0, files, runtime, force).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]LinkUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+// EnableUnitFiles() may be used to enable one or more units in the system (by
+// creating symlinks to them in /etc or /run).
+//
+// It takes a list of unit files to enable (either just file names or full
+// absolute paths if the unit files are residing outside the usual unit
+// search paths), and two booleans: the first controls whether the unit shall
+// be enabled for runtime only (true, /run), or persistently (false, /etc).
+// The second one controls whether symlinks pointing to other units shall
+// be replaced if necessary.
+//
+// This call returns one boolean and an array with the changes made. The
+// boolean signals whether the unit files contained any enablement
+// information (i.e. an [Install]) section. The changes list consists of
+// structures with three strings: the type of the change (one of symlink
+// or unlink), the file name of the symlink and the destination of the
+// symlink.
+func (c *Conn) EnableUnitFiles(files []string, runtime bool, force bool) (bool, []EnableUnitFileChange, error) {
+	var carries_install_info bool
+
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.EnableUnitFiles", 0, files, runtime, force).Store(&carries_install_info, &result)
+	if err != nil {
+		return false, nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]EnableUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return false, nil, err
+	}
+
+	return carries_install_info, changes, nil
+}
+
+type EnableUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// DisableUnitFiles() may be used to disable one or more units in the system (by
+// removing symlinks to them from /etc or /run).
+//
+// It takes a list of unit files to disable (either just file names or full
+// absolute paths if the unit files are residing outside the usual unit
+// search paths), and one boolean: whether the unit was enabled for runtime
+// only (true, /run), or persistently (false, /etc).
+//
+// This call returns an array with the changes made. The changes list
+// consists of structures with three strings: the type of the change (one of
+// symlink or unlink), the file name of the symlink and the destination of the
+// symlink.
+func (c *Conn) DisableUnitFiles(files []string, runtime bool) ([]DisableUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.DisableUnitFiles", 0, files, runtime).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]DisableUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+type DisableUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// MaskUnitFiles masks one or more units in the system
+//
+// It takes three arguments:
+//   * list of units to mask (either just file names or full
+//     absolute paths if the unit files are residing outside
+//     the usual unit search paths)
+//   * runtime to specify whether the unit was enabled for runtime
+//     only (true, /run/systemd/..), or persistently (false, /etc/systemd/..)
+//   * force flag
+func (c *Conn) MaskUnitFiles(files []string, runtime bool, force bool) ([]MaskUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.MaskUnitFiles", 0, files, runtime, force).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]MaskUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+type MaskUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// UnmaskUnitFiles unmasks one or more units in the system
+//
+// It takes two arguments:
+//   * list of unit files to mask (either just file names or full
+//     absolute paths if the unit files are residing outside
+//     the usual unit search paths)
+//   * runtime to specify whether the unit was enabled for runtime
+//     only (true, /run/systemd/..), or persistently (false, /etc/systemd/..)
+func (c *Conn) UnmaskUnitFiles(files []string, runtime bool) ([]UnmaskUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.UnmaskUnitFiles", 0, files, runtime).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]UnmaskUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+type UnmaskUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// Reload instructs systemd to scan for and reload unit files. This is
+// equivalent to a 'systemctl daemon-reload'.
+func (c *Conn) Reload() error {
+	return c.sysobj.Call("org.freedesktop.systemd1.Manager.Reload", 0).Store()
+}
+
+func unitPath(name string) dbus.ObjectPath {
+	return dbus.ObjectPath("/org/freedesktop/systemd1/unit/" + PathBusEscape(name))
+}
+
+// unitName returns the unescaped base element of the supplied escaped path
+func unitName(dpath dbus.ObjectPath) string {
+	return pathBusUnescape(path.Base(string(dpath)))
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/dbus/properties.go b/vendor/github.com/coreos/go-systemd/v22/dbus/properties.go
new file mode 100644
index 000000000..fb42b6273
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/dbus/properties.go
@@ -0,0 +1,237 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"github.com/godbus/dbus/v5"
+)
+
+// From the systemd docs:
+//
+// The properties array of StartTransientUnit() may take many of the settings
+// that may also be configured in unit files. Not all parameters are currently
+// accepted though, but we plan to cover more properties with future release.
+// Currently you may set the Description, Slice and all dependency types of
+// units, as well as RemainAfterExit, ExecStart for service units,
+// TimeoutStopUSec and PIDs for scope units, and CPUAccounting, CPUShares,
+// BlockIOAccounting, BlockIOWeight, BlockIOReadBandwidth,
+// BlockIOWriteBandwidth, BlockIODeviceWeight, MemoryAccounting, MemoryLimit,
+// DevicePolicy, DeviceAllow for services/scopes/slices. These fields map
+// directly to their counterparts in unit files and as normal D-Bus object
+// properties. The exception here is the PIDs field of scope units which is
+// used for construction of the scope only and specifies the initial PIDs to
+// add to the scope object.
+
+type Property struct {
+	Name  string
+	Value dbus.Variant
+}
+
+type PropertyCollection struct {
+	Name       string
+	Properties []Property
+}
+
+type execStart struct {
+	Path             string   // the binary path to execute
+	Args             []string // an array with all arguments to pass to the executed command, starting with argument 0
+	UncleanIsFailure bool     // a boolean whether it should be considered a failure if the process exits uncleanly
+}
+
+// PropExecStart sets the ExecStart service property.  The first argument is a
+// slice with the binary path to execute followed by the arguments to pass to
+// the executed command. See
+// http://www.freedesktop.org/software/systemd/man/systemd.service.html#ExecStart=
+func PropExecStart(command []string, uncleanIsFailure bool) Property {
+	execStarts := []execStart{
+		{
+			Path:             command[0],
+			Args:             command,
+			UncleanIsFailure: uncleanIsFailure,
+		},
+	}
+
+	return Property{
+		Name:  "ExecStart",
+		Value: dbus.MakeVariant(execStarts),
+	}
+}
+
+// PropRemainAfterExit sets the RemainAfterExit service property. See
+// http://www.freedesktop.org/software/systemd/man/systemd.service.html#RemainAfterExit=
+func PropRemainAfterExit(b bool) Property {
+	return Property{
+		Name:  "RemainAfterExit",
+		Value: dbus.MakeVariant(b),
+	}
+}
+
+// PropType sets the Type service property. See
+// http://www.freedesktop.org/software/systemd/man/systemd.service.html#Type=
+func PropType(t string) Property {
+	return Property{
+		Name:  "Type",
+		Value: dbus.MakeVariant(t),
+	}
+}
+
+// PropDescription sets the Description unit property. See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit#Description=
+func PropDescription(desc string) Property {
+	return Property{
+		Name:  "Description",
+		Value: dbus.MakeVariant(desc),
+	}
+}
+
+func propDependency(name string, units []string) Property {
+	return Property{
+		Name:  name,
+		Value: dbus.MakeVariant(units),
+	}
+}
+
+// PropRequires sets the Requires unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Requires=
+func PropRequires(units ...string) Property {
+	return propDependency("Requires", units)
+}
+
+// PropRequiresOverridable sets the RequiresOverridable unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiresOverridable=
+func PropRequiresOverridable(units ...string) Property {
+	return propDependency("RequiresOverridable", units)
+}
+
+// PropRequisite sets the Requisite unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Requisite=
+func PropRequisite(units ...string) Property {
+	return propDependency("Requisite", units)
+}
+
+// PropRequisiteOverridable sets the RequisiteOverridable unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequisiteOverridable=
+func PropRequisiteOverridable(units ...string) Property {
+	return propDependency("RequisiteOverridable", units)
+}
+
+// PropWants sets the Wants unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Wants=
+func PropWants(units ...string) Property {
+	return propDependency("Wants", units)
+}
+
+// PropBindsTo sets the BindsTo unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#BindsTo=
+func PropBindsTo(units ...string) Property {
+	return propDependency("BindsTo", units)
+}
+
+// PropRequiredBy sets the RequiredBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiredBy=
+func PropRequiredBy(units ...string) Property {
+	return propDependency("RequiredBy", units)
+}
+
+// PropRequiredByOverridable sets the RequiredByOverridable unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiredByOverridable=
+func PropRequiredByOverridable(units ...string) Property {
+	return propDependency("RequiredByOverridable", units)
+}
+
+// PropWantedBy sets the WantedBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#WantedBy=
+func PropWantedBy(units ...string) Property {
+	return propDependency("WantedBy", units)
+}
+
+// PropBoundBy sets the BoundBy unit property.  See
+// http://www.freedesktop.org/software/systemd/main/systemd.unit.html#BoundBy=
+func PropBoundBy(units ...string) Property {
+	return propDependency("BoundBy", units)
+}
+
+// PropConflicts sets the Conflicts unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Conflicts=
+func PropConflicts(units ...string) Property {
+	return propDependency("Conflicts", units)
+}
+
+// PropConflictedBy sets the ConflictedBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#ConflictedBy=
+func PropConflictedBy(units ...string) Property {
+	return propDependency("ConflictedBy", units)
+}
+
+// PropBefore sets the Before unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Before=
+func PropBefore(units ...string) Property {
+	return propDependency("Before", units)
+}
+
+// PropAfter sets the After unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#After=
+func PropAfter(units ...string) Property {
+	return propDependency("After", units)
+}
+
+// PropOnFailure sets the OnFailure unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#OnFailure=
+func PropOnFailure(units ...string) Property {
+	return propDependency("OnFailure", units)
+}
+
+// PropTriggers sets the Triggers unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Triggers=
+func PropTriggers(units ...string) Property {
+	return propDependency("Triggers", units)
+}
+
+// PropTriggeredBy sets the TriggeredBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#TriggeredBy=
+func PropTriggeredBy(units ...string) Property {
+	return propDependency("TriggeredBy", units)
+}
+
+// PropPropagatesReloadTo sets the PropagatesReloadTo unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#PropagatesReloadTo=
+func PropPropagatesReloadTo(units ...string) Property {
+	return propDependency("PropagatesReloadTo", units)
+}
+
+// PropRequiresMountsFor sets the RequiresMountsFor unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiresMountsFor=
+func PropRequiresMountsFor(units ...string) Property {
+	return propDependency("RequiresMountsFor", units)
+}
+
+// PropSlice sets the Slice unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.resource-control.html#Slice=
+func PropSlice(slice string) Property {
+	return Property{
+		Name:  "Slice",
+		Value: dbus.MakeVariant(slice),
+	}
+}
+
+// PropPids sets the PIDs field of scope units used in the initial construction
+// of the scope only and specifies the initial PIDs to add to the scope object.
+// See https://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/#properties
+func PropPids(pids ...uint32) Property {
+	return Property{
+		Name:  "PIDs",
+		Value: dbus.MakeVariant(pids),
+	}
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/dbus/set.go b/vendor/github.com/coreos/go-systemd/v22/dbus/set.go
new file mode 100644
index 000000000..17c5d4856
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/dbus/set.go
@@ -0,0 +1,47 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+type set struct {
+	data map[string]bool
+}
+
+func (s *set) Add(value string) {
+	s.data[value] = true
+}
+
+func (s *set) Remove(value string) {
+	delete(s.data, value)
+}
+
+func (s *set) Contains(value string) (exists bool) {
+	_, exists = s.data[value]
+	return
+}
+
+func (s *set) Length() int {
+	return len(s.data)
+}
+
+func (s *set) Values() (values []string) {
+	for val := range s.data {
+		values = append(values, val)
+	}
+	return
+}
+
+func newSet() *set {
+	return &set{make(map[string]bool)}
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/dbus/subscription.go b/vendor/github.com/coreos/go-systemd/v22/dbus/subscription.go
new file mode 100644
index 000000000..7e370fea2
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/dbus/subscription.go
@@ -0,0 +1,333 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"errors"
+	"log"
+	"time"
+
+	"github.com/godbus/dbus/v5"
+)
+
+const (
+	cleanIgnoreInterval = int64(10 * time.Second)
+	ignoreInterval      = int64(30 * time.Millisecond)
+)
+
+// Subscribe sets up this connection to subscribe to all systemd dbus events.
+// This is required before calling SubscribeUnits. When the connection closes
+// systemd will automatically stop sending signals so there is no need to
+// explicitly call Unsubscribe().
+func (c *Conn) Subscribe() error {
+	c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
+		"type='signal',interface='org.freedesktop.systemd1.Manager',member='UnitNew'")
+	c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
+		"type='signal',interface='org.freedesktop.DBus.Properties',member='PropertiesChanged'")
+
+	return c.sigobj.Call("org.freedesktop.systemd1.Manager.Subscribe", 0).Store()
+}
+
+// Unsubscribe this connection from systemd dbus events.
+func (c *Conn) Unsubscribe() error {
+	return c.sigobj.Call("org.freedesktop.systemd1.Manager.Unsubscribe", 0).Store()
+}
+
+func (c *Conn) dispatch() {
+	ch := make(chan *dbus.Signal, signalBuffer)
+
+	c.sigconn.Signal(ch)
+
+	go func() {
+		for {
+			signal, ok := <-ch
+			if !ok {
+				return
+			}
+
+			if signal.Name == "org.freedesktop.systemd1.Manager.JobRemoved" {
+				c.jobComplete(signal)
+			}
+
+			if c.subStateSubscriber.updateCh == nil &&
+				c.propertiesSubscriber.updateCh == nil {
+				continue
+			}
+
+			var unitPath dbus.ObjectPath
+			switch signal.Name {
+			case "org.freedesktop.systemd1.Manager.JobRemoved":
+				unitName := signal.Body[2].(string)
+				c.sysobj.Call("org.freedesktop.systemd1.Manager.GetUnit", 0, unitName).Store(&unitPath)
+			case "org.freedesktop.systemd1.Manager.UnitNew":
+				unitPath = signal.Body[1].(dbus.ObjectPath)
+			case "org.freedesktop.DBus.Properties.PropertiesChanged":
+				if signal.Body[0].(string) == "org.freedesktop.systemd1.Unit" {
+					unitPath = signal.Path
+
+					if len(signal.Body) >= 2 {
+						if changed, ok := signal.Body[1].(map[string]dbus.Variant); ok {
+							c.sendPropertiesUpdate(unitPath, changed)
+						}
+					}
+				}
+			}
+
+			if unitPath == dbus.ObjectPath("") {
+				continue
+			}
+
+			c.sendSubStateUpdate(unitPath)
+		}
+	}()
+}
+
+// SubscribeUnits returns two unbuffered channels which will receive all changed units every
+// interval.  Deleted units are sent as nil.
+func (c *Conn) SubscribeUnits(interval time.Duration) (<-chan map[string]*UnitStatus, <-chan error) {
+	return c.SubscribeUnitsCustom(interval, 0, func(u1, u2 *UnitStatus) bool { return *u1 != *u2 }, nil)
+}
+
+// SubscribeUnitsCustom is like SubscribeUnits but lets you specify the buffer
+// size of the channels, the comparison function for detecting changes and a filter
+// function for cutting down on the noise that your channel receives.
+func (c *Conn) SubscribeUnitsCustom(interval time.Duration, buffer int, isChanged func(*UnitStatus, *UnitStatus) bool, filterUnit func(string) bool) (<-chan map[string]*UnitStatus, <-chan error) {
+	old := make(map[string]*UnitStatus)
+	statusChan := make(chan map[string]*UnitStatus, buffer)
+	errChan := make(chan error, buffer)
+
+	go func() {
+		for {
+			timerChan := time.After(interval)
+
+			units, err := c.ListUnits()
+			if err == nil {
+				cur := make(map[string]*UnitStatus)
+				for i := range units {
+					if filterUnit != nil && filterUnit(units[i].Name) {
+						continue
+					}
+					cur[units[i].Name] = &units[i]
+				}
+
+				// add all new or changed units
+				changed := make(map[string]*UnitStatus)
+				for n, u := range cur {
+					if oldU, ok := old[n]; !ok || isChanged(oldU, u) {
+						changed[n] = u
+					}
+					delete(old, n)
+				}
+
+				// add all deleted units
+				for oldN := range old {
+					changed[oldN] = nil
+				}
+
+				old = cur
+
+				if len(changed) != 0 {
+					statusChan <- changed
+				}
+			} else {
+				errChan <- err
+			}
+
+			<-timerChan
+		}
+	}()
+
+	return statusChan, errChan
+}
+
+type SubStateUpdate struct {
+	UnitName string
+	SubState string
+}
+
+// SetSubStateSubscriber writes to updateCh when any unit's substate changes.
+// Although this writes to updateCh on every state change, the reported state
+// may be more recent than the change that generated it (due to an unavoidable
+// race in the systemd dbus interface).  That is, this method provides a good
+// way to keep a current view of all units' states, but is not guaranteed to
+// show every state transition they go through.  Furthermore, state changes
+// will only be written to the channel with non-blocking writes.  If updateCh
+// is full, it attempts to write an error to errCh; if errCh is full, the error
+// passes silently.
+func (c *Conn) SetSubStateSubscriber(updateCh chan<- *SubStateUpdate, errCh chan<- error) {
+	if c == nil {
+		msg := "nil receiver"
+		select {
+		case errCh <- errors.New(msg):
+		default:
+			log.Printf("full error channel while reporting: %s\n", msg)
+		}
+		return
+	}
+
+	c.subStateSubscriber.Lock()
+	defer c.subStateSubscriber.Unlock()
+	c.subStateSubscriber.updateCh = updateCh
+	c.subStateSubscriber.errCh = errCh
+}
+
+func (c *Conn) sendSubStateUpdate(unitPath dbus.ObjectPath) {
+	c.subStateSubscriber.Lock()
+	defer c.subStateSubscriber.Unlock()
+
+	if c.subStateSubscriber.updateCh == nil {
+		return
+	}
+
+	isIgnored := c.shouldIgnore(unitPath)
+	defer c.cleanIgnore()
+	if isIgnored {
+		return
+	}
+
+	info, err := c.GetUnitPathProperties(unitPath)
+	if err != nil {
+		select {
+		case c.subStateSubscriber.errCh <- err:
+		default:
+			log.Printf("full error channel while reporting: %s\n", err)
+		}
+		return
+	}
+	defer c.updateIgnore(unitPath, info)
+
+	name, ok := info["Id"].(string)
+	if !ok {
+		msg := "failed to cast info.Id"
+		select {
+		case c.subStateSubscriber.errCh <- errors.New(msg):
+		default:
+			log.Printf("full error channel while reporting: %s\n", err)
+		}
+		return
+	}
+	substate, ok := info["SubState"].(string)
+	if !ok {
+		msg := "failed to cast info.SubState"
+		select {
+		case c.subStateSubscriber.errCh <- errors.New(msg):
+		default:
+			log.Printf("full error channel while reporting: %s\n", msg)
+		}
+		return
+	}
+
+	update := &SubStateUpdate{name, substate}
+	select {
+	case c.subStateSubscriber.updateCh <- update:
+	default:
+		msg := "update channel is full"
+		select {
+		case c.subStateSubscriber.errCh <- errors.New(msg):
+		default:
+			log.Printf("full error channel while reporting: %s\n", msg)
+		}
+		return
+	}
+}
+
+// The ignore functions work around a wart in the systemd dbus interface.
+// Requesting the properties of an unloaded unit will cause systemd to send a
+// pair of UnitNew/UnitRemoved signals.  Because we need to get a unit's
+// properties on UnitNew (as that's the only indication of a new unit coming up
+// for the first time), we would enter an infinite loop if we did not attempt
+// to detect and ignore these spurious signals.  The signal themselves are
+// indistinguishable from relevant ones, so we (somewhat hackishly) ignore an
+// unloaded unit's signals for a short time after requesting its properties.
+// This means that we will miss e.g. a transient unit being restarted
+// *immediately* upon failure and also a transient unit being started
+// immediately after requesting its status (with systemctl status, for example,
+// because this causes a UnitNew signal to be sent which then causes us to fetch
+// the properties).
+
+func (c *Conn) shouldIgnore(path dbus.ObjectPath) bool {
+	t, ok := c.subStateSubscriber.ignore[path]
+	return ok && t >= time.Now().UnixNano()
+}
+
+func (c *Conn) updateIgnore(path dbus.ObjectPath, info map[string]interface{}) {
+	loadState, ok := info["LoadState"].(string)
+	if !ok {
+		return
+	}
+
+	// unit is unloaded - it will trigger bad systemd dbus behavior
+	if loadState == "not-found" {
+		c.subStateSubscriber.ignore[path] = time.Now().UnixNano() + ignoreInterval
+	}
+}
+
+// without this, ignore would grow unboundedly over time
+func (c *Conn) cleanIgnore() {
+	now := time.Now().UnixNano()
+	if c.subStateSubscriber.cleanIgnore < now {
+		c.subStateSubscriber.cleanIgnore = now + cleanIgnoreInterval
+
+		for p, t := range c.subStateSubscriber.ignore {
+			if t < now {
+				delete(c.subStateSubscriber.ignore, p)
+			}
+		}
+	}
+}
+
+// PropertiesUpdate holds a map of a unit's changed properties
+type PropertiesUpdate struct {
+	UnitName string
+	Changed  map[string]dbus.Variant
+}
+
+// SetPropertiesSubscriber writes to updateCh when any unit's properties
+// change. Every property change reported by systemd will be sent; that is, no
+// transitions will be "missed" (as they might be with SetSubStateSubscriber).
+// However, state changes will only be written to the channel with non-blocking
+// writes.  If updateCh is full, it attempts to write an error to errCh; if
+// errCh is full, the error passes silently.
+func (c *Conn) SetPropertiesSubscriber(updateCh chan<- *PropertiesUpdate, errCh chan<- error) {
+	c.propertiesSubscriber.Lock()
+	defer c.propertiesSubscriber.Unlock()
+	c.propertiesSubscriber.updateCh = updateCh
+	c.propertiesSubscriber.errCh = errCh
+}
+
+// we don't need to worry about shouldIgnore() here because
+// sendPropertiesUpdate doesn't call GetProperties()
+func (c *Conn) sendPropertiesUpdate(unitPath dbus.ObjectPath, changedProps map[string]dbus.Variant) {
+	c.propertiesSubscriber.Lock()
+	defer c.propertiesSubscriber.Unlock()
+
+	if c.propertiesSubscriber.updateCh == nil {
+		return
+	}
+
+	update := &PropertiesUpdate{unitName(unitPath), changedProps}
+
+	select {
+	case c.propertiesSubscriber.updateCh <- update:
+	default:
+		msg := "update channel is full"
+		select {
+		case c.propertiesSubscriber.errCh <- errors.New(msg):
+		default:
+			log.Printf("full error channel while reporting: %s\n", msg)
+		}
+		return
+	}
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/dbus/subscription_set.go b/vendor/github.com/coreos/go-systemd/v22/dbus/subscription_set.go
new file mode 100644
index 000000000..5b408d584
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/dbus/subscription_set.go
@@ -0,0 +1,57 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"time"
+)
+
+// SubscriptionSet returns a subscription set which is like conn.Subscribe but
+// can filter to only return events for a set of units.
+type SubscriptionSet struct {
+	*set
+	conn *Conn
+}
+
+func (s *SubscriptionSet) filter(unit string) bool {
+	return !s.Contains(unit)
+}
+
+// Subscribe starts listening for dbus events for all of the units in the set.
+// Returns channels identical to conn.SubscribeUnits.
+func (s *SubscriptionSet) Subscribe() (<-chan map[string]*UnitStatus, <-chan error) {
+	// TODO: Make fully evented by using systemd 209 with properties changed values
+	return s.conn.SubscribeUnitsCustom(time.Second, 0,
+		mismatchUnitStatus,
+		func(unit string) bool { return s.filter(unit) },
+	)
+}
+
+// NewSubscriptionSet returns a new subscription set.
+func (conn *Conn) NewSubscriptionSet() *SubscriptionSet {
+	return &SubscriptionSet{newSet(), conn}
+}
+
+// mismatchUnitStatus returns true if the provided UnitStatus objects
+// are not equivalent. false is returned if the objects are equivalent.
+// Only the Name, Description and state-related fields are used in
+// the comparison.
+func mismatchUnitStatus(u1, u2 *UnitStatus) bool {
+	return u1.Name != u2.Name ||
+		u1.Description != u2.Description ||
+		u1.LoadState != u2.LoadState ||
+		u1.ActiveState != u2.ActiveState ||
+		u1.SubState != u2.SubState
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/internal/dlopen/dlopen.go b/vendor/github.com/coreos/go-systemd/v22/internal/dlopen/dlopen.go
new file mode 100644
index 000000000..23774f612
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/internal/dlopen/dlopen.go
@@ -0,0 +1,82 @@
+// Copyright 2016 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package dlopen provides some convenience functions to dlopen a library and
+// get its symbols.
+package dlopen
+
+// #cgo LDFLAGS: -ldl
+// #include <stdlib.h>
+// #include <dlfcn.h>
+import "C"
+import (
+	"errors"
+	"fmt"
+	"unsafe"
+)
+
+var ErrSoNotFound = errors.New("unable to open a handle to the library")
+
+// LibHandle represents an open handle to a library (.so)
+type LibHandle struct {
+	Handle  unsafe.Pointer
+	Libname string
+}
+
+// GetHandle tries to get a handle to a library (.so), attempting to access it
+// by the names specified in libs and returning the first that is successfully
+// opened. Callers are responsible for closing the handler. If no library can
+// be successfully opened, an error is returned.
+func GetHandle(libs []string) (*LibHandle, error) {
+	for _, name := range libs {
+		libname := C.CString(name)
+		defer C.free(unsafe.Pointer(libname))
+		handle := C.dlopen(libname, C.RTLD_LAZY)
+		if handle != nil {
+			h := &LibHandle{
+				Handle:  handle,
+				Libname: name,
+			}
+			return h, nil
+		}
+	}
+	return nil, ErrSoNotFound
+}
+
+// GetSymbolPointer takes a symbol name and returns a pointer to the symbol.
+func (l *LibHandle) GetSymbolPointer(symbol string) (unsafe.Pointer, error) {
+	sym := C.CString(symbol)
+	defer C.free(unsafe.Pointer(sym))
+
+	C.dlerror()
+	p := C.dlsym(l.Handle, sym)
+	e := C.dlerror()
+	if e != nil {
+		return nil, fmt.Errorf("error resolving symbol %q: %v", symbol, errors.New(C.GoString(e)))
+	}
+
+	return p, nil
+}
+
+// Close closes a LibHandle.
+func (l *LibHandle) Close() error {
+	C.dlerror()
+	C.dlclose(l.Handle)
+	e := C.dlerror()
+	if e != nil {
+		return fmt.Errorf("error closing %v: %v", l.Libname, errors.New(C.GoString(e)))
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/journal/journal.go b/vendor/github.com/coreos/go-systemd/v22/journal/journal.go
new file mode 100644
index 000000000..a0f4837a0
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/journal/journal.go
@@ -0,0 +1,225 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package journal provides write bindings to the local systemd journal.
+// It is implemented in pure Go and connects to the journal directly over its
+// unix socket.
+//
+// To read from the journal, see the "sdjournal" package, which wraps the
+// sd-journal a C API.
+//
+// http://www.freedesktop.org/software/systemd/man/systemd-journald.service.html
+package journal
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"syscall"
+	"unsafe"
+)
+
+// Priority of a journal message
+type Priority int
+
+const (
+	PriEmerg Priority = iota
+	PriAlert
+	PriCrit
+	PriErr
+	PriWarning
+	PriNotice
+	PriInfo
+	PriDebug
+)
+
+var (
+	// This can be overridden at build-time:
+	// https://github.com/golang/go/wiki/GcToolchainTricks#including-build-information-in-the-executable
+	journalSocket = "/run/systemd/journal/socket"
+
+	// unixConnPtr atomically holds the local unconnected Unix-domain socket.
+	// Concrete safe pointer type: *net.UnixConn
+	unixConnPtr unsafe.Pointer
+	// onceConn ensures that unixConnPtr is initialized exactly once.
+	onceConn sync.Once
+)
+
+func init() {
+	onceConn.Do(initConn)
+}
+
+// Enabled checks whether the local systemd journal is available for logging.
+func Enabled() bool {
+	onceConn.Do(initConn)
+
+	if (*net.UnixConn)(atomic.LoadPointer(&unixConnPtr)) == nil {
+		return false
+	}
+
+	if _, err := net.Dial("unixgram", journalSocket); err != nil {
+		return false
+	}
+
+	return true
+}
+
+// Send a message to the local systemd journal. vars is a map of journald
+// fields to values.  Fields must be composed of uppercase letters, numbers,
+// and underscores, but must not start with an underscore. Within these
+// restrictions, any arbitrary field name may be used.  Some names have special
+// significance: see the journalctl documentation
+// (http://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html)
+// for more details.  vars may be nil.
+func Send(message string, priority Priority, vars map[string]string) error {
+	conn := (*net.UnixConn)(atomic.LoadPointer(&unixConnPtr))
+	if conn == nil {
+		return errors.New("could not initialize socket to journald")
+	}
+
+	socketAddr := &net.UnixAddr{
+		Name: journalSocket,
+		Net:  "unixgram",
+	}
+
+	data := new(bytes.Buffer)
+	appendVariable(data, "PRIORITY", strconv.Itoa(int(priority)))
+	appendVariable(data, "MESSAGE", message)
+	for k, v := range vars {
+		appendVariable(data, k, v)
+	}
+
+	_, _, err := conn.WriteMsgUnix(data.Bytes(), nil, socketAddr)
+	if err == nil {
+		return nil
+	}
+	if !isSocketSpaceError(err) {
+		return err
+	}
+
+	// Large log entry, send it via tempfile and ancillary-fd.
+	file, err := tempFd()
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	_, err = io.Copy(file, data)
+	if err != nil {
+		return err
+	}
+	rights := syscall.UnixRights(int(file.Fd()))
+	_, _, err = conn.WriteMsgUnix([]byte{}, rights, socketAddr)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Print prints a message to the local systemd journal using Send().
+func Print(priority Priority, format string, a ...interface{}) error {
+	return Send(fmt.Sprintf(format, a...), priority, nil)
+}
+
+func appendVariable(w io.Writer, name, value string) {
+	if err := validVarName(name); err != nil {
+		fmt.Fprintf(os.Stderr, "variable name %s contains invalid character, ignoring\n", name)
+	}
+	if strings.ContainsRune(value, '\n') {
+		/* When the value contains a newline, we write:
+		 * - the variable name, followed by a newline
+		 * - the size (in 64bit little endian format)
+		 * - the data, followed by a newline
+		 */
+		fmt.Fprintln(w, name)
+		binary.Write(w, binary.LittleEndian, uint64(len(value)))
+		fmt.Fprintln(w, value)
+	} else {
+		/* just write the variable and value all on one line */
+		fmt.Fprintf(w, "%s=%s\n", name, value)
+	}
+}
+
+// validVarName validates a variable name to make sure journald will accept it.
+// The variable name must be in uppercase and consist only of characters,
+// numbers and underscores, and may not begin with an underscore:
+// https://www.freedesktop.org/software/systemd/man/sd_journal_print.html
+func validVarName(name string) error {
+	if name == "" {
+		return errors.New("Empty variable name")
+	} else if name[0] == '_' {
+		return errors.New("Variable name begins with an underscore")
+	}
+
+	for _, c := range name {
+		if !(('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || c == '_') {
+			return errors.New("Variable name contains invalid characters")
+		}
+	}
+	return nil
+}
+
+// isSocketSpaceError checks whether the error is signaling
+// an "overlarge message" condition.
+func isSocketSpaceError(err error) bool {
+	opErr, ok := err.(*net.OpError)
+	if !ok || opErr == nil {
+		return false
+	}
+
+	sysErr, ok := opErr.Err.(*os.SyscallError)
+	if !ok || sysErr == nil {
+		return false
+	}
+
+	return sysErr.Err == syscall.EMSGSIZE || sysErr.Err == syscall.ENOBUFS
+}
+
+// tempFd creates a temporary, unlinked file under `/dev/shm`.
+func tempFd() (*os.File, error) {
+	file, err := ioutil.TempFile("/dev/shm/", "journal.XXXXX")
+	if err != nil {
+		return nil, err
+	}
+	err = syscall.Unlink(file.Name())
+	if err != nil {
+		return nil, err
+	}
+	return file, nil
+}
+
+// initConn initializes the global `unixConnPtr` socket.
+// It is meant to be called exactly once, at program startup.
+func initConn() {
+	autobind, err := net.ResolveUnixAddr("unixgram", "")
+	if err != nil {
+		return
+	}
+
+	sock, err := net.ListenUnixgram("unixgram", autobind)
+	if err != nil {
+		return
+	}
+
+	atomic.StorePointer(&unixConnPtr, unsafe.Pointer(sock))
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/sdjournal/functions.go b/vendor/github.com/coreos/go-systemd/v22/sdjournal/functions.go
new file mode 100644
index 000000000..3cbd05658
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/sdjournal/functions.go
@@ -0,0 +1,66 @@
+// Copyright 2015 RedHat, Inc.
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sdjournal
+
+import (
+	"github.com/coreos/go-systemd/v22/internal/dlopen"
+	"sync"
+	"unsafe"
+)
+
+var (
+	// lazy initialized
+	libsystemdHandle *dlopen.LibHandle
+
+	libsystemdMutex     = &sync.Mutex{}
+	libsystemdFunctions = map[string]unsafe.Pointer{}
+	libsystemdNames     = []string{
+		// systemd < 209
+		"libsystemd-journal.so.0",
+		"libsystemd-journal.so",
+
+		// systemd >= 209 merged libsystemd-journal into libsystemd proper
+		"libsystemd.so.0",
+		"libsystemd.so",
+	}
+)
+
+func getFunction(name string) (unsafe.Pointer, error) {
+	libsystemdMutex.Lock()
+	defer libsystemdMutex.Unlock()
+
+	if libsystemdHandle == nil {
+		h, err := dlopen.GetHandle(libsystemdNames)
+		if err != nil {
+			return nil, err
+		}
+
+		libsystemdHandle = h
+	}
+
+	f, ok := libsystemdFunctions[name]
+	if !ok {
+		var err error
+		f, err = libsystemdHandle.GetSymbolPointer(name)
+		if err != nil {
+			return nil, err
+		}
+
+		libsystemdFunctions[name] = f
+	}
+
+	return f, nil
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/sdjournal/journal.go b/vendor/github.com/coreos/go-systemd/v22/sdjournal/journal.go
new file mode 100644
index 000000000..7f840def8
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/sdjournal/journal.go
@@ -0,0 +1,1120 @@
+// Copyright 2015 RedHat, Inc.
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package sdjournal provides a low-level Go interface to the
+// systemd journal wrapped around the sd-journal C API.
+//
+// All public read methods map closely to the sd-journal API functions. See the
+// sd-journal.h documentation[1] for information about each function.
+//
+// To write to the journal, see the pure-Go "journal" package
+//
+// [1] http://www.freedesktop.org/software/systemd/man/sd-journal.html
+package sdjournal
+
+// #include <systemd/sd-journal.h>
+// #include <systemd/sd-id128.h>
+// #include <stdlib.h>
+// #include <syslog.h>
+//
+// int
+// my_sd_journal_open(void *f, sd_journal **ret, int flags)
+// {
+//   int (*sd_journal_open)(sd_journal **, int);
+//
+//   sd_journal_open = f;
+//   return sd_journal_open(ret, flags);
+// }
+//
+// int
+// my_sd_journal_open_directory(void *f, sd_journal **ret, const char *path, int flags)
+// {
+//   int (*sd_journal_open_directory)(sd_journal **, const char *, int);
+//
+//   sd_journal_open_directory = f;
+//   return sd_journal_open_directory(ret, path, flags);
+// }
+//
+// int
+// my_sd_journal_open_files(void *f, sd_journal **ret, const char **paths, int flags)
+// {
+//   int (*sd_journal_open_files)(sd_journal **, const char **, int);
+//
+//   sd_journal_open_files = f;
+//   return sd_journal_open_files(ret, paths, flags);
+// }
+//
+// void
+// my_sd_journal_close(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_close)(sd_journal *);
+//
+//   sd_journal_close = f;
+//   sd_journal_close(j);
+// }
+//
+// int
+// my_sd_journal_get_usage(void *f, sd_journal *j, uint64_t *bytes)
+// {
+//   int (*sd_journal_get_usage)(sd_journal *, uint64_t *);
+//
+//   sd_journal_get_usage = f;
+//   return sd_journal_get_usage(j, bytes);
+// }
+//
+// int
+// my_sd_journal_add_match(void *f, sd_journal *j, const void *data, size_t size)
+// {
+//   int (*sd_journal_add_match)(sd_journal *, const void *, size_t);
+//
+//   sd_journal_add_match = f;
+//   return sd_journal_add_match(j, data, size);
+// }
+//
+// int
+// my_sd_journal_add_disjunction(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_add_disjunction)(sd_journal *);
+//
+//   sd_journal_add_disjunction = f;
+//   return sd_journal_add_disjunction(j);
+// }
+//
+// int
+// my_sd_journal_add_conjunction(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_add_conjunction)(sd_journal *);
+//
+//   sd_journal_add_conjunction = f;
+//   return sd_journal_add_conjunction(j);
+// }
+//
+// void
+// my_sd_journal_flush_matches(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_flush_matches)(sd_journal *);
+//
+//   sd_journal_flush_matches = f;
+//   sd_journal_flush_matches(j);
+// }
+//
+// int
+// my_sd_journal_next(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_next)(sd_journal *);
+//
+//   sd_journal_next = f;
+//   return sd_journal_next(j);
+// }
+//
+// int
+// my_sd_journal_next_skip(void *f, sd_journal *j, uint64_t skip)
+// {
+//   int (*sd_journal_next_skip)(sd_journal *, uint64_t);
+//
+//   sd_journal_next_skip = f;
+//   return sd_journal_next_skip(j, skip);
+// }
+//
+// int
+// my_sd_journal_previous(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_previous)(sd_journal *);
+//
+//   sd_journal_previous = f;
+//   return sd_journal_previous(j);
+// }
+//
+// int
+// my_sd_journal_previous_skip(void *f, sd_journal *j, uint64_t skip)
+// {
+//   int (*sd_journal_previous_skip)(sd_journal *, uint64_t);
+//
+//   sd_journal_previous_skip = f;
+//   return sd_journal_previous_skip(j, skip);
+// }
+//
+// int
+// my_sd_journal_get_data(void *f, sd_journal *j, const char *field, const void **data, size_t *length)
+// {
+//   int (*sd_journal_get_data)(sd_journal *, const char *, const void **, size_t *);
+//
+//   sd_journal_get_data = f;
+//   return sd_journal_get_data(j, field, data, length);
+// }
+//
+// int
+// my_sd_journal_set_data_threshold(void *f, sd_journal *j, size_t sz)
+// {
+//   int (*sd_journal_set_data_threshold)(sd_journal *, size_t);
+//
+//   sd_journal_set_data_threshold = f;
+//   return sd_journal_set_data_threshold(j, sz);
+// }
+//
+// int
+// my_sd_journal_get_cursor(void *f, sd_journal *j, char **cursor)
+// {
+//   int (*sd_journal_get_cursor)(sd_journal *, char **);
+//
+//   sd_journal_get_cursor = f;
+//   return sd_journal_get_cursor(j, cursor);
+// }
+//
+// int
+// my_sd_journal_test_cursor(void *f, sd_journal *j, const char *cursor)
+// {
+//   int (*sd_journal_test_cursor)(sd_journal *, const char *);
+//
+//   sd_journal_test_cursor = f;
+//   return sd_journal_test_cursor(j, cursor);
+// }
+//
+// int
+// my_sd_journal_get_realtime_usec(void *f, sd_journal *j, uint64_t *usec)
+// {
+//   int (*sd_journal_get_realtime_usec)(sd_journal *, uint64_t *);
+//
+//   sd_journal_get_realtime_usec = f;
+//   return sd_journal_get_realtime_usec(j, usec);
+// }
+//
+// int
+// my_sd_journal_get_monotonic_usec(void *f, sd_journal *j, uint64_t *usec, sd_id128_t *boot_id)
+// {
+//   int (*sd_journal_get_monotonic_usec)(sd_journal *, uint64_t *, sd_id128_t *);
+//
+//   sd_journal_get_monotonic_usec = f;
+//   return sd_journal_get_monotonic_usec(j, usec, boot_id);
+// }
+//
+// int
+// my_sd_journal_seek_head(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_seek_head)(sd_journal *);
+//
+//   sd_journal_seek_head = f;
+//   return sd_journal_seek_head(j);
+// }
+//
+// int
+// my_sd_journal_seek_tail(void *f, sd_journal *j)
+// {
+//   int (*sd_journal_seek_tail)(sd_journal *);
+//
+//   sd_journal_seek_tail = f;
+//   return sd_journal_seek_tail(j);
+// }
+//
+//
+// int
+// my_sd_journal_seek_cursor(void *f, sd_journal *j, const char *cursor)
+// {
+//   int (*sd_journal_seek_cursor)(sd_journal *, const char *);
+//
+//   sd_journal_seek_cursor = f;
+//   return sd_journal_seek_cursor(j, cursor);
+// }
+//
+// int
+// my_sd_journal_seek_realtime_usec(void *f, sd_journal *j, uint64_t usec)
+// {
+//   int (*sd_journal_seek_realtime_usec)(sd_journal *, uint64_t);
+//
+//   sd_journal_seek_realtime_usec = f;
+//   return sd_journal_seek_realtime_usec(j, usec);
+// }
+//
+// int
+// my_sd_journal_wait(void *f, sd_journal *j, uint64_t timeout_usec)
+// {
+//   int (*sd_journal_wait)(sd_journal *, uint64_t);
+//
+//   sd_journal_wait = f;
+//   return sd_journal_wait(j, timeout_usec);
+// }
+//
+// void
+// my_sd_journal_restart_data(void *f, sd_journal *j)
+// {
+//   void (*sd_journal_restart_data)(sd_journal *);
+//
+//   sd_journal_restart_data = f;
+//   sd_journal_restart_data(j);
+// }
+//
+// int
+// my_sd_journal_enumerate_data(void *f, sd_journal *j, const void **data, size_t *length)
+// {
+//   int (*sd_journal_enumerate_data)(sd_journal *, const void **, size_t *);
+//
+//   sd_journal_enumerate_data = f;
+//   return sd_journal_enumerate_data(j, data, length);
+// }
+//
+// int
+// my_sd_journal_query_unique(void *f, sd_journal *j, const char *field)
+// {
+//   int(*sd_journal_query_unique)(sd_journal *, const char *);
+//
+//   sd_journal_query_unique = f;
+//   return sd_journal_query_unique(j, field);
+// }
+//
+// int
+// my_sd_journal_enumerate_unique(void *f, sd_journal *j, const void **data, size_t *length)
+// {
+//   int(*sd_journal_enumerate_unique)(sd_journal *, const void **, size_t *);
+//
+//   sd_journal_enumerate_unique = f;
+//   return sd_journal_enumerate_unique(j, data, length);
+// }
+//
+// void
+// my_sd_journal_restart_unique(void *f, sd_journal *j)
+// {
+//   void(*sd_journal_restart_unique)(sd_journal *);
+//
+//   sd_journal_restart_unique = f;
+//   sd_journal_restart_unique(j);
+// }
+//
+// int
+// my_sd_journal_get_catalog(void *f, sd_journal *j, char **ret)
+// {
+//   int(*sd_journal_get_catalog)(sd_journal *, char **);
+//
+//   sd_journal_get_catalog = f;
+//   return sd_journal_get_catalog(j, ret);
+// }
+//
+import "C"
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+// Journal entry field strings which correspond to:
+// http://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html
+const (
+	// User Journal Fields
+	SD_JOURNAL_FIELD_MESSAGE           = "MESSAGE"
+	SD_JOURNAL_FIELD_MESSAGE_ID        = "MESSAGE_ID"
+	SD_JOURNAL_FIELD_PRIORITY          = "PRIORITY"
+	SD_JOURNAL_FIELD_CODE_FILE         = "CODE_FILE"
+	SD_JOURNAL_FIELD_CODE_LINE         = "CODE_LINE"
+	SD_JOURNAL_FIELD_CODE_FUNC         = "CODE_FUNC"
+	SD_JOURNAL_FIELD_ERRNO             = "ERRNO"
+	SD_JOURNAL_FIELD_SYSLOG_FACILITY   = "SYSLOG_FACILITY"
+	SD_JOURNAL_FIELD_SYSLOG_IDENTIFIER = "SYSLOG_IDENTIFIER"
+	SD_JOURNAL_FIELD_SYSLOG_PID        = "SYSLOG_PID"
+
+	// Trusted Journal Fields
+	SD_JOURNAL_FIELD_PID                       = "_PID"
+	SD_JOURNAL_FIELD_UID                       = "_UID"
+	SD_JOURNAL_FIELD_GID                       = "_GID"
+	SD_JOURNAL_FIELD_COMM                      = "_COMM"
+	SD_JOURNAL_FIELD_EXE                       = "_EXE"
+	SD_JOURNAL_FIELD_CMDLINE                   = "_CMDLINE"
+	SD_JOURNAL_FIELD_CAP_EFFECTIVE             = "_CAP_EFFECTIVE"
+	SD_JOURNAL_FIELD_AUDIT_SESSION             = "_AUDIT_SESSION"
+	SD_JOURNAL_FIELD_AUDIT_LOGINUID            = "_AUDIT_LOGINUID"
+	SD_JOURNAL_FIELD_SYSTEMD_CGROUP            = "_SYSTEMD_CGROUP"
+	SD_JOURNAL_FIELD_SYSTEMD_SESSION           = "_SYSTEMD_SESSION"
+	SD_JOURNAL_FIELD_SYSTEMD_UNIT              = "_SYSTEMD_UNIT"
+	SD_JOURNAL_FIELD_SYSTEMD_USER_UNIT         = "_SYSTEMD_USER_UNIT"
+	SD_JOURNAL_FIELD_SYSTEMD_OWNER_UID         = "_SYSTEMD_OWNER_UID"
+	SD_JOURNAL_FIELD_SYSTEMD_SLICE             = "_SYSTEMD_SLICE"
+	SD_JOURNAL_FIELD_SELINUX_CONTEXT           = "_SELINUX_CONTEXT"
+	SD_JOURNAL_FIELD_SOURCE_REALTIME_TIMESTAMP = "_SOURCE_REALTIME_TIMESTAMP"
+	SD_JOURNAL_FIELD_BOOT_ID                   = "_BOOT_ID"
+	SD_JOURNAL_FIELD_MACHINE_ID                = "_MACHINE_ID"
+	SD_JOURNAL_FIELD_HOSTNAME                  = "_HOSTNAME"
+	SD_JOURNAL_FIELD_TRANSPORT                 = "_TRANSPORT"
+
+	// Address Fields
+	SD_JOURNAL_FIELD_CURSOR              = "__CURSOR"
+	SD_JOURNAL_FIELD_REALTIME_TIMESTAMP  = "__REALTIME_TIMESTAMP"
+	SD_JOURNAL_FIELD_MONOTONIC_TIMESTAMP = "__MONOTONIC_TIMESTAMP"
+)
+
+// Journal event constants
+const (
+	SD_JOURNAL_NOP        = int(C.SD_JOURNAL_NOP)
+	SD_JOURNAL_APPEND     = int(C.SD_JOURNAL_APPEND)
+	SD_JOURNAL_INVALIDATE = int(C.SD_JOURNAL_INVALIDATE)
+)
+
+const (
+	// IndefiniteWait is a sentinel value that can be passed to
+	// sdjournal.Wait() to signal an indefinite wait for new journal
+	// events. It is implemented as the maximum value for a time.Duration:
+	// https://github.com/golang/go/blob/e4dcf5c8c22d98ac9eac7b9b226596229624cb1d/src/time/time.go#L434
+	IndefiniteWait time.Duration = 1<<63 - 1
+)
+
+var (
+	// ErrNoTestCursor gets returned when using TestCursor function and cursor
+	// parameter is not the same as the current cursor position.
+	ErrNoTestCursor = errors.New("Cursor parameter is not the same as current position")
+)
+
+// Journal is a Go wrapper of an sd_journal structure.
+type Journal struct {
+	cjournal *C.sd_journal
+	mu       sync.Mutex
+}
+
+// JournalEntry represents all fields of a journal entry plus address fields.
+type JournalEntry struct {
+	Fields             map[string]string
+	Cursor             string
+	RealtimeTimestamp  uint64
+	MonotonicTimestamp uint64
+}
+
+// Match is a convenience wrapper to describe filters supplied to AddMatch.
+type Match struct {
+	Field string
+	Value string
+}
+
+// String returns a string representation of a Match suitable for use with AddMatch.
+func (m *Match) String() string {
+	return m.Field + "=" + m.Value
+}
+
+// NewJournal returns a new Journal instance pointing to the local journal
+func NewJournal() (j *Journal, err error) {
+	j = &Journal{}
+
+	sd_journal_open, err := getFunction("sd_journal_open")
+	if err != nil {
+		return nil, err
+	}
+
+	r := C.my_sd_journal_open(sd_journal_open, &j.cjournal, C.SD_JOURNAL_LOCAL_ONLY)
+
+	if r < 0 {
+		return nil, fmt.Errorf("failed to open journal: %s", syscall.Errno(-r).Error())
+	}
+
+	return j, nil
+}
+
+// NewJournalFromDir returns a new Journal instance pointing to a journal residing
+// in a given directory.
+func NewJournalFromDir(path string) (j *Journal, err error) {
+	j = &Journal{}
+
+	sd_journal_open_directory, err := getFunction("sd_journal_open_directory")
+	if err != nil {
+		return nil, err
+	}
+
+	p := C.CString(path)
+	defer C.free(unsafe.Pointer(p))
+
+	r := C.my_sd_journal_open_directory(sd_journal_open_directory, &j.cjournal, p, 0)
+	if r < 0 {
+		return nil, fmt.Errorf("failed to open journal in directory %q: %s", path, syscall.Errno(-r).Error())
+	}
+
+	return j, nil
+}
+
+// NewJournalFromFiles returns a new Journal instance pointing to a journals residing
+// in a given files.
+func NewJournalFromFiles(paths ...string) (j *Journal, err error) {
+	j = &Journal{}
+
+	sd_journal_open_files, err := getFunction("sd_journal_open_files")
+	if err != nil {
+		return nil, err
+	}
+
+	// by making the slice 1 elem too long, we guarantee it'll be null-terminated
+	cPaths := make([]*C.char, len(paths)+1)
+	for idx, path := range paths {
+		p := C.CString(path)
+		cPaths[idx] = p
+		defer C.free(unsafe.Pointer(p))
+	}
+
+	r := C.my_sd_journal_open_files(sd_journal_open_files, &j.cjournal, &cPaths[0], 0)
+	if r < 0 {
+		return nil, fmt.Errorf("failed to open journals in paths %q: %s", paths, syscall.Errno(-r).Error())
+	}
+
+	return j, nil
+}
+
+// Close closes a journal opened with NewJournal.
+func (j *Journal) Close() error {
+	sd_journal_close, err := getFunction("sd_journal_close")
+	if err != nil {
+		return err
+	}
+
+	j.mu.Lock()
+	C.my_sd_journal_close(sd_journal_close, j.cjournal)
+	j.mu.Unlock()
+
+	return nil
+}
+
+// AddMatch adds a match by which to filter the entries of the journal.
+func (j *Journal) AddMatch(match string) error {
+	sd_journal_add_match, err := getFunction("sd_journal_add_match")
+	if err != nil {
+		return err
+	}
+
+	m := C.CString(match)
+	defer C.free(unsafe.Pointer(m))
+
+	j.mu.Lock()
+	r := C.my_sd_journal_add_match(sd_journal_add_match, j.cjournal, unsafe.Pointer(m), C.size_t(len(match)))
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to add match: %s", syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// AddDisjunction inserts a logical OR in the match list.
+func (j *Journal) AddDisjunction() error {
+	sd_journal_add_disjunction, err := getFunction("sd_journal_add_disjunction")
+	if err != nil {
+		return err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_add_disjunction(sd_journal_add_disjunction, j.cjournal)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to add a disjunction in the match list: %s", syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// AddConjunction inserts a logical AND in the match list.
+func (j *Journal) AddConjunction() error {
+	sd_journal_add_conjunction, err := getFunction("sd_journal_add_conjunction")
+	if err != nil {
+		return err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_add_conjunction(sd_journal_add_conjunction, j.cjournal)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to add a conjunction in the match list: %s", syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// FlushMatches flushes all matches, disjunctions and conjunctions.
+func (j *Journal) FlushMatches() {
+	sd_journal_flush_matches, err := getFunction("sd_journal_flush_matches")
+	if err != nil {
+		return
+	}
+
+	j.mu.Lock()
+	C.my_sd_journal_flush_matches(sd_journal_flush_matches, j.cjournal)
+	j.mu.Unlock()
+}
+
+// Next advances the read pointer into the journal by one entry.
+func (j *Journal) Next() (uint64, error) {
+	sd_journal_next, err := getFunction("sd_journal_next")
+	if err != nil {
+		return 0, err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_next(sd_journal_next, j.cjournal)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return 0, fmt.Errorf("failed to iterate journal: %s", syscall.Errno(-r).Error())
+	}
+
+	return uint64(r), nil
+}
+
+// NextSkip advances the read pointer by multiple entries at once,
+// as specified by the skip parameter.
+func (j *Journal) NextSkip(skip uint64) (uint64, error) {
+	sd_journal_next_skip, err := getFunction("sd_journal_next_skip")
+	if err != nil {
+		return 0, err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_next_skip(sd_journal_next_skip, j.cjournal, C.uint64_t(skip))
+	j.mu.Unlock()
+
+	if r < 0 {
+		return 0, fmt.Errorf("failed to iterate journal: %s", syscall.Errno(-r).Error())
+	}
+
+	return uint64(r), nil
+}
+
+// Previous sets the read pointer into the journal back by one entry.
+func (j *Journal) Previous() (uint64, error) {
+	sd_journal_previous, err := getFunction("sd_journal_previous")
+	if err != nil {
+		return 0, err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_previous(sd_journal_previous, j.cjournal)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return 0, fmt.Errorf("failed to iterate journal: %s", syscall.Errno(-r).Error())
+	}
+
+	return uint64(r), nil
+}
+
+// PreviousSkip sets back the read pointer by multiple entries at once,
+// as specified by the skip parameter.
+func (j *Journal) PreviousSkip(skip uint64) (uint64, error) {
+	sd_journal_previous_skip, err := getFunction("sd_journal_previous_skip")
+	if err != nil {
+		return 0, err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_previous_skip(sd_journal_previous_skip, j.cjournal, C.uint64_t(skip))
+	j.mu.Unlock()
+
+	if r < 0 {
+		return 0, fmt.Errorf("failed to iterate journal: %s", syscall.Errno(-r).Error())
+	}
+
+	return uint64(r), nil
+}
+
+func (j *Journal) getData(field string) (unsafe.Pointer, C.int, error) {
+	sd_journal_get_data, err := getFunction("sd_journal_get_data")
+	if err != nil {
+		return nil, 0, err
+	}
+
+	f := C.CString(field)
+	defer C.free(unsafe.Pointer(f))
+
+	var d unsafe.Pointer
+	var l C.size_t
+
+	j.mu.Lock()
+	r := C.my_sd_journal_get_data(sd_journal_get_data, j.cjournal, f, &d, &l)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return nil, 0, fmt.Errorf("failed to read message: %s", syscall.Errno(-r).Error())
+	}
+
+	return d, C.int(l), nil
+}
+
+// GetData gets the data object associated with a specific field from the
+// the journal entry referenced by the last completed Next/Previous function
+// call. To call GetData, you must have first called one of these functions.
+func (j *Journal) GetData(field string) (string, error) {
+	d, l, err := j.getData(field)
+	if err != nil {
+		return "", err
+	}
+
+	return C.GoStringN((*C.char)(d), l), nil
+}
+
+// GetDataValue gets the data object associated with a specific field from the
+// journal entry referenced by the last completed Next/Previous function call,
+// returning only the value of the object. To call GetDataValue, you must first
+// have called one of the Next/Previous functions.
+func (j *Journal) GetDataValue(field string) (string, error) {
+	val, err := j.GetData(field)
+	if err != nil {
+		return "", err
+	}
+
+	return strings.SplitN(val, "=", 2)[1], nil
+}
+
+// GetDataBytes gets the data object associated with a specific field from the
+// journal entry referenced by the last completed Next/Previous function call.
+// To call GetDataBytes, you must first have called one of these functions.
+func (j *Journal) GetDataBytes(field string) ([]byte, error) {
+	d, l, err := j.getData(field)
+	if err != nil {
+		return nil, err
+	}
+
+	return C.GoBytes(d, l), nil
+}
+
+// GetDataValueBytes gets the data object associated with a specific field from the
+// journal entry referenced by the last completed Next/Previous function call,
+// returning only the value of the object. To call GetDataValueBytes, you must first
+// have called one of the Next/Previous functions.
+func (j *Journal) GetDataValueBytes(field string) ([]byte, error) {
+	val, err := j.GetDataBytes(field)
+	if err != nil {
+		return nil, err
+	}
+
+	return bytes.SplitN(val, []byte("="), 2)[1], nil
+}
+
+// GetEntry returns a full representation of the journal entry referenced by the
+// last completed Next/Previous function call, with all key-value pairs of data
+// as well as address fields (cursor, realtime timestamp and monotonic timestamp).
+// To call GetEntry, you must first have called one of the Next/Previous functions.
+func (j *Journal) GetEntry() (*JournalEntry, error) {
+	sd_journal_get_realtime_usec, err := getFunction("sd_journal_get_realtime_usec")
+	if err != nil {
+		return nil, err
+	}
+
+	sd_journal_get_monotonic_usec, err := getFunction("sd_journal_get_monotonic_usec")
+	if err != nil {
+		return nil, err
+	}
+
+	sd_journal_get_cursor, err := getFunction("sd_journal_get_cursor")
+	if err != nil {
+		return nil, err
+	}
+
+	sd_journal_restart_data, err := getFunction("sd_journal_restart_data")
+	if err != nil {
+		return nil, err
+	}
+
+	sd_journal_enumerate_data, err := getFunction("sd_journal_enumerate_data")
+	if err != nil {
+		return nil, err
+	}
+
+	j.mu.Lock()
+	defer j.mu.Unlock()
+
+	var r C.int
+	entry := &JournalEntry{Fields: make(map[string]string)}
+
+	var realtimeUsec C.uint64_t
+	r = C.my_sd_journal_get_realtime_usec(sd_journal_get_realtime_usec, j.cjournal, &realtimeUsec)
+	if r < 0 {
+		return nil, fmt.Errorf("failed to get realtime timestamp: %s", syscall.Errno(-r).Error())
+	}
+
+	entry.RealtimeTimestamp = uint64(realtimeUsec)
+
+	var monotonicUsec C.uint64_t
+	var boot_id C.sd_id128_t
+
+	r = C.my_sd_journal_get_monotonic_usec(sd_journal_get_monotonic_usec, j.cjournal, &monotonicUsec, &boot_id)
+	if r < 0 {
+		return nil, fmt.Errorf("failed to get monotonic timestamp: %s", syscall.Errno(-r).Error())
+	}
+
+	entry.MonotonicTimestamp = uint64(monotonicUsec)
+
+	var c *C.char
+	// since the pointer is mutated by sd_journal_get_cursor, need to wait
+	// until after the call to free the memory
+	r = C.my_sd_journal_get_cursor(sd_journal_get_cursor, j.cjournal, &c)
+	defer C.free(unsafe.Pointer(c))
+	if r < 0 {
+		return nil, fmt.Errorf("failed to get cursor: %s", syscall.Errno(-r).Error())
+	}
+
+	entry.Cursor = C.GoString(c)
+
+	// Implements the JOURNAL_FOREACH_DATA_RETVAL macro from journal-internal.h
+	var d unsafe.Pointer
+	var l C.size_t
+	C.my_sd_journal_restart_data(sd_journal_restart_data, j.cjournal)
+	for {
+		r = C.my_sd_journal_enumerate_data(sd_journal_enumerate_data, j.cjournal, &d, &l)
+		if r == 0 {
+			break
+		}
+
+		if r < 0 {
+			return nil, fmt.Errorf("failed to read message field: %s", syscall.Errno(-r).Error())
+		}
+
+		msg := C.GoStringN((*C.char)(d), C.int(l))
+		kv := strings.SplitN(msg, "=", 2)
+		if len(kv) < 2 {
+			return nil, fmt.Errorf("failed to parse field")
+		}
+
+		entry.Fields[kv[0]] = kv[1]
+	}
+
+	return entry, nil
+}
+
+// SetDataThreshold sets the data field size threshold for data returned by
+// GetData. To retrieve the complete data fields this threshold should be
+// turned off by setting it to 0, so that the library always returns the
+// complete data objects.
+func (j *Journal) SetDataThreshold(threshold uint64) error {
+	sd_journal_set_data_threshold, err := getFunction("sd_journal_set_data_threshold")
+	if err != nil {
+		return err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_set_data_threshold(sd_journal_set_data_threshold, j.cjournal, C.size_t(threshold))
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to set data threshold: %s", syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// GetRealtimeUsec gets the realtime (wallclock) timestamp of the journal
+// entry referenced by the last completed Next/Previous function call. To
+// call GetRealtimeUsec, you must first have called one of the Next/Previous
+// functions.
+func (j *Journal) GetRealtimeUsec() (uint64, error) {
+	var usec C.uint64_t
+
+	sd_journal_get_realtime_usec, err := getFunction("sd_journal_get_realtime_usec")
+	if err != nil {
+		return 0, err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_get_realtime_usec(sd_journal_get_realtime_usec, j.cjournal, &usec)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return 0, fmt.Errorf("failed to get realtime timestamp: %s", syscall.Errno(-r).Error())
+	}
+
+	return uint64(usec), nil
+}
+
+// GetMonotonicUsec gets the monotonic timestamp of the journal entry
+// referenced by the last completed Next/Previous function call. To call
+// GetMonotonicUsec, you must first have called one of the Next/Previous
+// functions.
+func (j *Journal) GetMonotonicUsec() (uint64, error) {
+	var usec C.uint64_t
+	var boot_id C.sd_id128_t
+
+	sd_journal_get_monotonic_usec, err := getFunction("sd_journal_get_monotonic_usec")
+	if err != nil {
+		return 0, err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_get_monotonic_usec(sd_journal_get_monotonic_usec, j.cjournal, &usec, &boot_id)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return 0, fmt.Errorf("failed to get monotonic timestamp: %s", syscall.Errno(-r).Error())
+	}
+
+	return uint64(usec), nil
+}
+
+// GetCursor gets the cursor of the last journal entry reeferenced by the
+// last completed Next/Previous function call. To call GetCursor, you must
+// first have called one of the Next/Previous functions.
+func (j *Journal) GetCursor() (string, error) {
+	sd_journal_get_cursor, err := getFunction("sd_journal_get_cursor")
+	if err != nil {
+		return "", err
+	}
+
+	var d *C.char
+	// since the pointer is mutated by sd_journal_get_cursor, need to wait
+	// until after the call to free the memory
+
+	j.mu.Lock()
+	r := C.my_sd_journal_get_cursor(sd_journal_get_cursor, j.cjournal, &d)
+	j.mu.Unlock()
+	defer C.free(unsafe.Pointer(d))
+
+	if r < 0 {
+		return "", fmt.Errorf("failed to get cursor: %s", syscall.Errno(-r).Error())
+	}
+
+	cursor := C.GoString(d)
+
+	return cursor, nil
+}
+
+// TestCursor checks whether the current position in the journal matches the
+// specified cursor
+func (j *Journal) TestCursor(cursor string) error {
+	sd_journal_test_cursor, err := getFunction("sd_journal_test_cursor")
+	if err != nil {
+		return err
+	}
+
+	c := C.CString(cursor)
+	defer C.free(unsafe.Pointer(c))
+
+	j.mu.Lock()
+	r := C.my_sd_journal_test_cursor(sd_journal_test_cursor, j.cjournal, c)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to test to cursor %q: %s", cursor, syscall.Errno(-r).Error())
+	} else if r == 0 {
+		return ErrNoTestCursor
+	}
+
+	return nil
+}
+
+// SeekHead seeks to the beginning of the journal, i.e. the oldest available
+// entry. This call must be followed by a call to Next before any call to
+// Get* will return data about the first element.
+func (j *Journal) SeekHead() error {
+	sd_journal_seek_head, err := getFunction("sd_journal_seek_head")
+	if err != nil {
+		return err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_seek_head(sd_journal_seek_head, j.cjournal)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to seek to head of journal: %s", syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// SeekTail may be used to seek to the end of the journal, i.e. the most recent
+// available entry. This call must be followed by a call to Next before any
+// call to Get* will return data about the last element.
+func (j *Journal) SeekTail() error {
+	sd_journal_seek_tail, err := getFunction("sd_journal_seek_tail")
+	if err != nil {
+		return err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_seek_tail(sd_journal_seek_tail, j.cjournal)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to seek to tail of journal: %s", syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// SeekRealtimeUsec seeks to the entry with the specified realtime (wallclock)
+// timestamp, i.e. CLOCK_REALTIME. This call must be followed by a call to
+// Next/Previous before any call to Get* will return data about the sought entry.
+func (j *Journal) SeekRealtimeUsec(usec uint64) error {
+	sd_journal_seek_realtime_usec, err := getFunction("sd_journal_seek_realtime_usec")
+	if err != nil {
+		return err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_seek_realtime_usec(sd_journal_seek_realtime_usec, j.cjournal, C.uint64_t(usec))
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to seek to %d: %s", usec, syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// SeekCursor seeks to a concrete journal cursor. This call must be
+// followed by a call to Next/Previous before any call to Get* will return
+// data about the sought entry.
+func (j *Journal) SeekCursor(cursor string) error {
+	sd_journal_seek_cursor, err := getFunction("sd_journal_seek_cursor")
+	if err != nil {
+		return err
+	}
+
+	c := C.CString(cursor)
+	defer C.free(unsafe.Pointer(c))
+
+	j.mu.Lock()
+	r := C.my_sd_journal_seek_cursor(sd_journal_seek_cursor, j.cjournal, c)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return fmt.Errorf("failed to seek to cursor %q: %s", cursor, syscall.Errno(-r).Error())
+	}
+
+	return nil
+}
+
+// Wait will synchronously wait until the journal gets changed. The maximum time
+// this call sleeps may be controlled with the timeout parameter.  If
+// sdjournal.IndefiniteWait is passed as the timeout parameter, Wait will
+// wait indefinitely for a journal change.
+func (j *Journal) Wait(timeout time.Duration) int {
+	var to uint64
+
+	sd_journal_wait, err := getFunction("sd_journal_wait")
+	if err != nil {
+		return -1
+	}
+
+	if timeout == IndefiniteWait {
+		// sd_journal_wait(3) calls for a (uint64_t) -1 to be passed to signify
+		// indefinite wait, but using a -1 overflows our C.uint64_t, so we use an
+		// equivalent hex value.
+		to = 0xffffffffffffffff
+	} else {
+		to = uint64(timeout / time.Microsecond)
+	}
+	j.mu.Lock()
+	r := C.my_sd_journal_wait(sd_journal_wait, j.cjournal, C.uint64_t(to))
+	j.mu.Unlock()
+
+	return int(r)
+}
+
+// GetUsage returns the journal disk space usage, in bytes.
+func (j *Journal) GetUsage() (uint64, error) {
+	var out C.uint64_t
+
+	sd_journal_get_usage, err := getFunction("sd_journal_get_usage")
+	if err != nil {
+		return 0, err
+	}
+
+	j.mu.Lock()
+	r := C.my_sd_journal_get_usage(sd_journal_get_usage, j.cjournal, &out)
+	j.mu.Unlock()
+
+	if r < 0 {
+		return 0, fmt.Errorf("failed to get journal disk space usage: %s", syscall.Errno(-r).Error())
+	}
+
+	return uint64(out), nil
+}
+
+// GetUniqueValues returns all unique values for a given field.
+func (j *Journal) GetUniqueValues(field string) ([]string, error) {
+	var result []string
+
+	sd_journal_query_unique, err := getFunction("sd_journal_query_unique")
+	if err != nil {
+		return nil, err
+	}
+
+	sd_journal_enumerate_unique, err := getFunction("sd_journal_enumerate_unique")
+	if err != nil {
+		return nil, err
+	}
+
+	sd_journal_restart_unique, err := getFunction("sd_journal_restart_unique")
+	if err != nil {
+		return nil, err
+	}
+
+	j.mu.Lock()
+	defer j.mu.Unlock()
+
+	f := C.CString(field)
+	defer C.free(unsafe.Pointer(f))
+
+	r := C.my_sd_journal_query_unique(sd_journal_query_unique, j.cjournal, f)
+
+	if r < 0 {
+		return nil, fmt.Errorf("failed to query journal: %s", syscall.Errno(-r).Error())
+	}
+
+	// Implements the SD_JOURNAL_FOREACH_UNIQUE macro from sd-journal.h
+	var d unsafe.Pointer
+	var l C.size_t
+	C.my_sd_journal_restart_unique(sd_journal_restart_unique, j.cjournal)
+	for {
+		r = C.my_sd_journal_enumerate_unique(sd_journal_enumerate_unique, j.cjournal, &d, &l)
+		if r == 0 {
+			break
+		}
+
+		if r < 0 {
+			return nil, fmt.Errorf("failed to read message field: %s", syscall.Errno(-r).Error())
+		}
+
+		msg := C.GoStringN((*C.char)(d), C.int(l))
+		kv := strings.SplitN(msg, "=", 2)
+		if len(kv) < 2 {
+			return nil, fmt.Errorf("failed to parse field")
+		}
+
+		result = append(result, kv[1])
+	}
+
+	return result, nil
+}
+
+// GetCatalog retrieves a message catalog entry for the journal entry referenced
+// by the last completed Next/Previous function call. To call GetCatalog, you
+// must first have called one of these functions.
+func (j *Journal) GetCatalog() (string, error) {
+	sd_journal_get_catalog, err := getFunction("sd_journal_get_catalog")
+	if err != nil {
+		return "", err
+	}
+
+	var c *C.char
+
+	j.mu.Lock()
+	r := C.my_sd_journal_get_catalog(sd_journal_get_catalog, j.cjournal, &c)
+	j.mu.Unlock()
+	defer C.free(unsafe.Pointer(c))
+
+	if r < 0 {
+		return "", fmt.Errorf("failed to retrieve catalog entry for current journal entry: %s", syscall.Errno(-r).Error())
+	}
+
+	catalog := C.GoString(c)
+
+	return catalog, nil
+}
diff --git a/vendor/github.com/coreos/go-systemd/v22/sdjournal/read.go b/vendor/github.com/coreos/go-systemd/v22/sdjournal/read.go
new file mode 100644
index 000000000..51a060fb5
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/v22/sdjournal/read.go
@@ -0,0 +1,272 @@
+// Copyright 2015 RedHat, Inc.
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sdjournal
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"strings"
+	"sync"
+	"time"
+)
+
+var (
+	// ErrExpired gets returned when the Follow function runs into the
+	// specified timeout.
+	ErrExpired = errors.New("Timeout expired")
+)
+
+// JournalReaderConfig represents options to drive the behavior of a JournalReader.
+type JournalReaderConfig struct {
+	// The Since, NumFromTail and Cursor options are mutually exclusive and
+	// determine where the reading begins within the journal. The order in which
+	// options are written is exactly the order of precedence.
+	Since       time.Duration // start relative to a Duration from now
+	NumFromTail uint64        // start relative to the tail
+	Cursor      string        // start relative to the cursor
+
+	// Show only journal entries whose fields match the supplied values. If
+	// the array is empty, entries will not be filtered.
+	Matches []Match
+
+	// If not empty, the journal instance will point to a journal residing
+	// in this directory. The supplied path may be relative or absolute.
+	Path string
+
+	// If not nil, Formatter will be used to translate the resulting entries
+	// into strings. If not set, the default format (timestamp and message field)
+	// will be used. If Formatter returns an error, Read will stop and return the error.
+	Formatter func(entry *JournalEntry) (string, error)
+}
+
+// JournalReader is an io.ReadCloser which provides a simple interface for iterating through the
+// systemd journal. A JournalReader is not safe for concurrent use by multiple goroutines.
+type JournalReader struct {
+	journal   *Journal
+	msgReader *strings.Reader
+	formatter func(entry *JournalEntry) (string, error)
+}
+
+// NewJournalReader creates a new JournalReader with configuration options that are similar to the
+// systemd journalctl tool's iteration and filtering features.
+func NewJournalReader(config JournalReaderConfig) (*JournalReader, error) {
+	// use simpleMessageFormatter as default formatter.
+	if config.Formatter == nil {
+		config.Formatter = simpleMessageFormatter
+	}
+
+	r := &JournalReader{
+		formatter: config.Formatter,
+	}
+
+	// Open the journal
+	var err error
+	if config.Path != "" {
+		r.journal, err = NewJournalFromDir(config.Path)
+	} else {
+		r.journal, err = NewJournal()
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	// Add any supplied matches
+	for _, m := range config.Matches {
+		if err = r.journal.AddMatch(m.String()); err != nil {
+			return nil, err
+		}
+	}
+
+	// Set the start position based on options
+	if config.Since != 0 {
+		// Start based on a relative time
+		start := time.Now().Add(config.Since)
+		if err := r.journal.SeekRealtimeUsec(uint64(start.UnixNano() / 1000)); err != nil {
+			return nil, err
+		}
+	} else if config.NumFromTail != 0 {
+		// Start based on a number of lines before the tail
+		if err := r.journal.SeekTail(); err != nil {
+			return nil, err
+		}
+
+		// Move the read pointer into position near the tail. Go one further than
+		// the option so that the initial cursor advancement positions us at the
+		// correct starting point.
+		skip, err := r.journal.PreviousSkip(config.NumFromTail + 1)
+		if err != nil {
+			return nil, err
+		}
+		// If we skipped fewer lines than expected, we have reached journal start.
+		// Thus, we seek to head so that next invocation can read the first line.
+		if skip != config.NumFromTail+1 {
+			if err := r.journal.SeekHead(); err != nil {
+				return nil, err
+			}
+		}
+	} else if config.Cursor != "" {
+		// Start based on a custom cursor
+		if err := r.journal.SeekCursor(config.Cursor); err != nil {
+			return nil, err
+		}
+	}
+
+	return r, nil
+}
+
+// Read reads entries from the journal. Read follows the Reader interface so
+// it must be able to read a specific amount of bytes. Journald on the other
+// hand only allows us to read full entries of arbitrary size (without byte
+// granularity). JournalReader is therefore internally buffering entries that
+// don't fit in the read buffer. Callers should keep calling until 0 and/or an
+// error is returned.
+func (r *JournalReader) Read(b []byte) (int, error) {
+	if r.msgReader == nil {
+		// Advance the journal cursor. It has to be called at least one time
+		// before reading
+		c, err := r.journal.Next()
+
+		// An unexpected error
+		if err != nil {
+			return 0, err
+		}
+
+		// EOF detection
+		if c == 0 {
+			return 0, io.EOF
+		}
+
+		entry, err := r.journal.GetEntry()
+		if err != nil {
+			return 0, err
+		}
+
+		// Build a message
+		msg, err := r.formatter(entry)
+		if err != nil {
+			return 0, err
+		}
+		r.msgReader = strings.NewReader(msg)
+	}
+
+	// Copy and return the message
+	sz, err := r.msgReader.Read(b)
+	if err == io.EOF {
+		// The current entry has been fully read. Don't propagate this
+		// EOF, so the next entry can be read at the next Read()
+		// iteration.
+		r.msgReader = nil
+		return sz, nil
+	}
+	if err != nil {
+		return sz, err
+	}
+	if r.msgReader.Len() == 0 {
+		r.msgReader = nil
+	}
+
+	return sz, nil
+}
+
+// Close closes the JournalReader's handle to the journal.
+func (r *JournalReader) Close() error {
+	return r.journal.Close()
+}
+
+// Rewind attempts to rewind the JournalReader to the first entry.
+func (r *JournalReader) Rewind() error {
+	r.msgReader = nil
+	return r.journal.SeekHead()
+}
+
+// Follow synchronously follows the JournalReader, writing each new journal entry to writer. The
+// follow will continue until a single time.Time is received on the until channel.
+func (r *JournalReader) Follow(until <-chan time.Time, writer io.Writer) error {
+
+	// Process journal entries and events. Entries are flushed until the tail or
+	// timeout is reached, and then we wait for new events or the timeout.
+	var msg = make([]byte, 64*1<<(10))
+	var waitCh = make(chan int, 1)
+	var waitGroup sync.WaitGroup
+	defer waitGroup.Wait()
+
+process:
+	for {
+		c, err := r.Read(msg)
+		if err != nil && err != io.EOF {
+			return err
+		}
+
+		select {
+		case <-until:
+			return ErrExpired
+		default:
+		}
+		if c > 0 {
+			if _, err = writer.Write(msg[:c]); err != nil {
+				return err
+			}
+			continue process
+		}
+
+		// We're at the tail, so wait for new events or time out.
+		// Holds journal events to process. Tightly bounded for now unless there's a
+		// reason to unblock the journal watch routine more quickly.
+		for {
+			waitGroup.Add(1)
+			go func() {
+				status := r.journal.Wait(100 * time.Millisecond)
+				waitCh <- status
+				waitGroup.Done()
+			}()
+
+			select {
+			case <-until:
+				return ErrExpired
+			case e := <-waitCh:
+				switch e {
+				case SD_JOURNAL_NOP:
+					// the journal did not change since the last invocation
+				case SD_JOURNAL_APPEND, SD_JOURNAL_INVALIDATE:
+					continue process
+				default:
+					if e < 0 {
+						return fmt.Errorf("received error event: %d", e)
+					}
+
+					log.Printf("received unknown event: %d\n", e)
+				}
+			}
+		}
+	}
+}
+
+// simpleMessageFormatter is the default formatter.
+// It returns a string representing the current journal entry in a simple format which
+// includes the entry timestamp and MESSAGE field.
+func simpleMessageFormatter(entry *JournalEntry) (string, error) {
+	msg, ok := entry.Fields["MESSAGE"]
+	if !ok {
+		return "", fmt.Errorf("no MESSAGE field present in journal entry")
+	}
+
+	usec := entry.RealtimeTimestamp
+	timestamp := time.Unix(0, int64(usec)*int64(time.Microsecond))
+
+	return fmt.Sprintf("%s %s\n", timestamp, msg), nil
+}