Merge pull request #2709 from haircommander/journald

Add libpod journald logging

12 files changed, 463 insertions, 136 deletions

diff --git a/vendor/github.com/coreos/go-systemd/NOTICE b/vendor/github.com/coreos/go-systemd/NOTICE
new file mode 100644
index 000000000..23a0ada2f
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/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/README.md b/vendor/github.com/coreos/go-systemd/README.md
index cb87a1124..cad04a803 100644
--- a/vendor/github.com/coreos/go-systemd/README.md
+++ b/vendor/github.com/coreos/go-systemd/README.md
@@ -6,9 +6,11 @@
 Go bindings to systemd. The project has several packages:
 
 - `activation` - for writing and using socket activation from Go
+- `daemon` - for notifying systemd of service status changes
 - `dbus` - for starting/stopping/inspecting running services and units
 - `journal` - for writing to systemd's logging service, journald
 - `sdjournal` - for reading from journald by wrapping its C API
+- `login1` - for integration with the systemd logind API
 - `machine1` - for registering machines/containers with systemd
 - `unit` - for (de)serialization and comparison of unit files
 
@@ -18,10 +20,9 @@ An example HTTP server using socket activation can be quickly set up by followin
 
 https://github.com/coreos/go-systemd/tree/master/examples/activation/httpserver
 
-## Journal
+## systemd Service Notification
 
-Using the pure-Go `journal` package you can submit journal entries directly to systemd's journal, taking advantage of features like indexed key/value pairs for each log entry.
-The `sdjournal` package provides read access to the journal by wrapping around journald's native C API; consequently it requires cgo and the journal headers to be available.
+The `daemon` package is an implementation of the [sd_notify protocol](https://www.freedesktop.org/software/systemd/man/sd_notify.html#Description). It can be used to inform systemd of service start-up completion, watchdog events, and other status changes.
 
 ## D-Bus
 
@@ -45,6 +46,20 @@ Create `/etc/dbus-1/system-local.conf` that looks like this:
 </busconfig>
 ```
 
+## Journal
+
+### Writing to the Journal
+
+Using the pure-Go `journal` package you can submit journal entries directly to systemd's journal, taking advantage of features like indexed key/value pairs for each log entry.
+
+### Reading from the Journal
+
+The `sdjournal` package provides read access to the journal by wrapping around journald's native C API; consequently it requires cgo and the journal headers to be available.
+
+## logind
+
+The `login1` package provides functions to integrate with the [systemd logind API](http://www.freedesktop.org/wiki/Software/systemd/logind/).
+
 ## machined
 
 The `machine1` package allows interaction with the [systemd machined D-Bus API](http://www.freedesktop.org/wiki/Software/systemd/machined/).
diff --git a/vendor/github.com/coreos/go-systemd/activation/files.go b/vendor/github.com/coreos/go-systemd/activation/files.go
index c8e85fcd5..29dd18def 100644
--- a/vendor/github.com/coreos/go-systemd/activation/files.go
+++ b/vendor/github.com/coreos/go-systemd/activation/files.go
@@ -18,18 +18,26 @@ package activation
 import (
 	"os"
 	"strconv"
+	"strings"
 	"syscall"
 )
 
-// based on: https://gist.github.com/alberts/4640792
 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"))
@@ -42,10 +50,17 @@ func Files(unsetEnv bool) []*os.File {
 		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)
-		files = append(files, os.NewFile(uintptr(fd), "LISTEN_FD_"+strconv.Itoa(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/activation/listeners.go b/vendor/github.com/coreos/go-systemd/activation/listeners.go
index fd5dfc709..bb5cc2311 100644
--- a/vendor/github.com/coreos/go-systemd/activation/listeners.go
+++ b/vendor/github.com/coreos/go-systemd/activation/listeners.go
@@ -25,13 +25,33 @@ import (
 // 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(unsetEnv bool) ([]net.Listener, error) {
-	files := Files(unsetEnv)
+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
@@ -40,8 +60,8 @@ func Listeners(unsetEnv bool) ([]net.Listener, error) {
 // 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(unsetEnv bool, tlsConfig *tls.Config) ([]net.Listener, error) {
-	listeners, err := Listeners(unsetEnv)
+func TLSListeners(tlsConfig *tls.Config) ([]net.Listener, error) {
+	listeners, err := Listeners()
 
 	if listeners == nil || err != nil {
 		return nil, err
@@ -58,3 +78,26 @@ func TLSListeners(unsetEnv bool, tlsConfig *tls.Config) ([]net.Listener, error)
 
 	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 && err == 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/activation/packetconns.go b/vendor/github.com/coreos/go-systemd/activation/packetconns.go
index 48b2ca029..a97206785 100644
--- a/vendor/github.com/coreos/go-systemd/activation/packetconns.go
+++ b/vendor/github.com/coreos/go-systemd/activation/packetconns.go
@@ -24,13 +24,14 @@ import (
 // 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(unsetEnv bool) ([]net.PacketConn, error) {
-	files := Files(unsetEnv)
+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/dbus/dbus.go b/vendor/github.com/coreos/go-systemd/dbus/dbus.go
index c1694fb52..1d54810af 100644
--- a/vendor/github.com/coreos/go-systemd/dbus/dbus.go
+++ b/vendor/github.com/coreos/go-systemd/dbus/dbus.go
@@ -16,6 +16,7 @@
 package dbus
 
 import (
+	"encoding/hex"
 	"fmt"
 	"os"
 	"strconv"
@@ -60,6 +61,27 @@ func PathBusEscape(path string) string {
 	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
@@ -74,13 +96,18 @@ type Conn struct {
 		jobs map[dbus.ObjectPath]chan<- string
 		sync.Mutex
 	}
-	subscriber struct {
+	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.
@@ -152,7 +179,7 @@ func NewConnection(dialBus func() (*dbus.Conn, error)) (*Conn, error) {
 		sigobj:  systemdObject(sigconn),
 	}
 
-	c.subscriber.ignore = make(map[dbus.ObjectPath]int64)
+	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
diff --git a/vendor/github.com/coreos/go-systemd/dbus/methods.go b/vendor/github.com/coreos/go-systemd/dbus/methods.go
index ab17f7cc7..0b4207229 100644
--- a/vendor/github.com/coreos/go-systemd/dbus/methods.go
+++ b/vendor/github.com/coreos/go-systemd/dbus/methods.go
@@ -1,4 +1,4 @@
-// Copyright 2015 CoreOS, Inc.
+// 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.
@@ -16,6 +16,7 @@ package dbus
 
 import (
 	"errors"
+	"fmt"
 	"path"
 	"strconv"
 
@@ -148,14 +149,27 @@ func (c *Conn) ResetFailedUnit(name string) error {
 	return c.sysobj.Call("org.freedesktop.systemd1.Manager.ResetFailedUnit", 0, name).Store()
 }
 
-// getProperties takes the unit name and returns all of its dbus object properties, for the given dbus interface
-func (c *Conn) getProperties(unit string, dbusInterface string) (map[string]interface{}, error) {
+// 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
 
-	path := unitPath(unit)
 	if !path.IsValid() {
-		return nil, errors.New("invalid unit name: " + unit)
+		return nil, fmt.Errorf("invalid unit name: %v", path)
 	}
 
 	obj := c.sysconn.Object("org.freedesktop.systemd1", path)
@@ -172,9 +186,15 @@ func (c *Conn) getProperties(unit string, dbusInterface string) (map[string]inte
 	return out, nil
 }
 
-// GetUnitProperties takes the unit name and returns all of its dbus object properties.
+// GetUnitProperties takes the (unescaped) unit name and returns all of its dbus object properties.
 func (c *Conn) GetUnitProperties(unit string) (map[string]interface{}, error) {
-	return c.getProperties(unit, "org.freedesktop.systemd1.Unit")
+	path := unitPath(unit)
+	return c.getProperties(path, "org.freedesktop.systemd1.Unit")
+}
+
+// GetUnitProperties 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")
 }
 
 func (c *Conn) getProperty(unit string, dbusInterface string, propertyName string) (*Property, error) {
@@ -208,7 +228,8 @@ func (c *Conn) GetServiceProperty(service string, propertyName string) (*Propert
 // 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) {
-	return c.getProperties(unit, "org.freedesktop.systemd1."+unitType)
+	path := unitPath(unit)
+	return c.getProperties(path, "org.freedesktop.systemd1."+unitType)
 }
 
 // SetUnitProperties() may be used to modify certain unit properties at runtime.
@@ -292,6 +313,7 @@ func (c *Conn) ListUnitsByPatterns(states []string, patterns []string) ([]UnitSt
 // 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)
 }
@@ -563,3 +585,8 @@ func (c *Conn) Reload() error {
 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/dbus/set.go b/vendor/github.com/coreos/go-systemd/dbus/set.go
index f92e6fbed..17c5d4856 100644
--- a/vendor/github.com/coreos/go-systemd/dbus/set.go
+++ b/vendor/github.com/coreos/go-systemd/dbus/set.go
@@ -36,7 +36,7 @@ func (s *set) Length() int {
 }
 
 func (s *set) Values() (values []string) {
-	for val, _ := range s.data {
+	for val := range s.data {
 		values = append(values, val)
 	}
 	return
diff --git a/vendor/github.com/coreos/go-systemd/dbus/subscription.go b/vendor/github.com/coreos/go-systemd/dbus/subscription.go
index 996451445..70e63a6f1 100644
--- a/vendor/github.com/coreos/go-systemd/dbus/subscription.go
+++ b/vendor/github.com/coreos/go-systemd/dbus/subscription.go
@@ -16,6 +16,7 @@ package dbus
 
 import (
 	"errors"
+	"log"
 	"time"
 
 	"github.com/godbus/dbus"
@@ -36,22 +37,12 @@ func (c *Conn) Subscribe() error {
 	c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
 		"type='signal',interface='org.freedesktop.DBus.Properties',member='PropertiesChanged'")
 
-	err := c.sigobj.Call("org.freedesktop.systemd1.Manager.Subscribe", 0).Store()
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return c.sigobj.Call("org.freedesktop.systemd1.Manager.Subscribe", 0).Store()
 }
 
 // Unsubscribe this connection from systemd dbus events.
 func (c *Conn) Unsubscribe() error {
-	err := c.sigobj.Call("org.freedesktop.systemd1.Manager.Unsubscribe", 0).Store()
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return c.sigobj.Call("org.freedesktop.systemd1.Manager.Unsubscribe", 0).Store()
 }
 
 func (c *Conn) dispatch() {
@@ -70,7 +61,8 @@ func (c *Conn) dispatch() {
 				c.jobComplete(signal)
 			}
 
-			if c.subscriber.updateCh == nil {
+			if c.subStateSubscriber.updateCh == nil &&
+				c.propertiesSubscriber.updateCh == nil {
 				continue
 			}
 
@@ -84,6 +76,12 @@ func (c *Conn) dispatch() {
 			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)
+						}
+					}
 				}
 			}
 
@@ -169,42 +167,80 @@ type SubStateUpdate struct {
 // 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) {
-	c.subscriber.Lock()
-	defer c.subscriber.Unlock()
-	c.subscriber.updateCh = updateCh
-	c.subscriber.errCh = errCh
+	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(path dbus.ObjectPath) {
-	c.subscriber.Lock()
-	defer c.subscriber.Unlock()
+func (c *Conn) sendSubStateUpdate(unitPath dbus.ObjectPath) {
+	c.subStateSubscriber.Lock()
+	defer c.subStateSubscriber.Unlock()
+
+	if c.subStateSubscriber.updateCh == nil {
+		return
+	}
 
-	if c.shouldIgnore(path) {
+	isIgnored := c.shouldIgnore(unitPath)
+	defer c.cleanIgnore()
+	if isIgnored {
 		return
 	}
 
-	info, err := c.GetUnitProperties(string(path))
+	info, err := c.GetUnitPathProperties(unitPath)
 	if err != nil {
 		select {
-		case c.subscriber.errCh <- err:
+		case c.subStateSubscriber.errCh <- err:
 		default:
+			log.Printf("full error channel while reporting: %s\n", err)
 		}
+		return
 	}
+	defer c.updateIgnore(unitPath, info)
 
-	name := info["Id"].(string)
-	substate := info["SubState"].(string)
+	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.subscriber.updateCh <- update:
+	case c.subStateSubscriber.updateCh <- update:
 	default:
+		msg := "update channel is full"
 		select {
-		case c.subscriber.errCh <- errors.New("update channel full!"):
+		case c.subStateSubscriber.errCh <- errors.New(msg):
 		default:
+			log.Printf("full error channel while reporting: %s\n", msg)
 		}
+		return
 	}
-
-	c.updateIgnore(path, info)
 }
 
 // The ignore functions work around a wart in the systemd dbus interface.
@@ -222,29 +258,76 @@ func (c *Conn) sendSubStateUpdate(path dbus.ObjectPath) {
 // the properties).
 
 func (c *Conn) shouldIgnore(path dbus.ObjectPath) bool {
-	t, ok := c.subscriber.ignore[path]
+	t, ok := c.subStateSubscriber.ignore[path]
 	return ok && t >= time.Now().UnixNano()
 }
 
 func (c *Conn) updateIgnore(path dbus.ObjectPath, info map[string]interface{}) {
-	c.cleanIgnore()
+	loadState, ok := info["LoadState"].(string)
+	if !ok {
+		return
+	}
 
 	// unit is unloaded - it will trigger bad systemd dbus behavior
-	if info["LoadState"].(string) == "not-found" {
-		c.subscriber.ignore[path] = time.Now().UnixNano() + ignoreInterval
+	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.subscriber.cleanIgnore < now {
-		c.subscriber.cleanIgnore = now + cleanIgnoreInterval
+	if c.subStateSubscriber.cleanIgnore < now {
+		c.subStateSubscriber.cleanIgnore = now + cleanIgnoreInterval
 
-		for p, t := range c.subscriber.ignore {
+		for p, t := range c.subStateSubscriber.ignore {
 			if t < now {
-				delete(c.subscriber.ignore, p)
+				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/journal/journal.go b/vendor/github.com/coreos/go-systemd/journal/journal.go
index 7f434990d..ef85a3ba2 100644
--- a/vendor/github.com/coreos/go-systemd/journal/journal.go
+++ b/vendor/github.com/coreos/go-systemd/journal/journal.go
@@ -103,7 +103,10 @@ func Send(message string, priority Priority, vars map[string]string) error {
 		if !ok {
 			return journalError("can't send file through non-Unix connection")
 		}
-		unixConn.WriteMsgUnix([]byte{}, rights, nil)
+		_, _, err = unixConn.WriteMsgUnix([]byte{}, rights, nil)
+		if err != nil {
+			return journalError(err.Error())
+		}
 	} else if err != nil {
 		return journalError(err.Error())
 	}
@@ -165,7 +168,7 @@ func tempFd() (*os.File, error) {
 	if err != nil {
 		return nil, err
 	}
-	syscall.Unlink(file.Name())
+	err = syscall.Unlink(file.Name())
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/github.com/coreos/go-systemd/sdjournal/journal.go b/vendor/github.com/coreos/go-systemd/sdjournal/journal.go
index b00d606c1..9f3d92342 100644
--- a/vendor/github.com/coreos/go-systemd/sdjournal/journal.go
+++ b/vendor/github.com/coreos/go-systemd/sdjournal/journal.go
@@ -47,6 +47,15 @@ package sdjournal
 //   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)
 // {
@@ -282,9 +291,19 @@ package sdjournal
 //   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"
@@ -352,6 +371,12 @@ const (
 	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
@@ -396,8 +421,7 @@ func NewJournal() (j *Journal, err error) {
 }
 
 // NewJournalFromDir returns a new Journal instance pointing to a journal residing
-// in a given directory. The supplied path may be relative or absolute; if
-// relative, it will be converted to an absolute path before being opened.
+// in a given directory.
 func NewJournalFromDir(path string) (j *Journal, err error) {
 	j = &Journal{}
 
@@ -417,6 +441,32 @@ func NewJournalFromDir(path string) (j *Journal, err 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: %d", paths, syscall.Errno(-r))
+	}
+
+	return j, nil
+}
+
 // Close closes a journal opened with NewJournal.
 func (j *Journal) Close() error {
 	sd_journal_close, err := getFunction("sd_journal_close")
@@ -598,7 +648,8 @@ func (j *Journal) getData(field string) (unsafe.Pointer, C.int, error) {
 }
 
 // GetData gets the data object associated with a specific field from the
-// current journal entry.
+// 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 {
@@ -609,7 +660,9 @@ func (j *Journal) GetData(field string) (string, error) {
 }
 
 // GetDataValue gets the data object associated with a specific field from the
-// current journal entry, returning only the value of the object.
+// 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 {
@@ -620,7 +673,8 @@ func (j *Journal) GetDataValue(field string) (string, error) {
 }
 
 // GetDataBytes gets the data object associated with a specific field from the
-// current journal entry.
+// 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 {
@@ -631,7 +685,9 @@ func (j *Journal) GetDataBytes(field string) ([]byte, error) {
 }
 
 // GetDataValueBytes gets the data object associated with a specific field from the
-// current journal entry, returning only the value of the object.
+// 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 {
@@ -641,9 +697,10 @@ func (j *Journal) GetDataValueBytes(field string) ([]byte, error) {
 	return bytes.SplitN(val, []byte("="), 2)[1], nil
 }
 
-// GetEntry returns a full representation of a journal entry with
-// all key-value pairs of data as well as address fields (cursor, realtime
-// timestamp and monotonic timestamp)
+// 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 {
@@ -731,7 +788,7 @@ func (j *Journal) GetEntry() (*JournalEntry, error) {
 	return entry, nil
 }
 
-// SetDataThresold sets the data field size threshold for data returned by
+// 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.
@@ -752,8 +809,10 @@ func (j *Journal) SetDataThreshold(threshold uint64) error {
 	return nil
 }
 
-// GetRealtimeUsec gets the realtime (wallclock) timestamp of the current
-// journal entry.
+// 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
 
@@ -773,7 +832,10 @@ func (j *Journal) GetRealtimeUsec() (uint64, error) {
 	return uint64(usec), nil
 }
 
-// GetMonotonicUsec gets the monotonic timestamp of the current journal entry.
+// 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
@@ -794,7 +856,9 @@ func (j *Journal) GetMonotonicUsec() (uint64, error) {
 	return uint64(usec), nil
 }
 
-// GetCursor gets the cursor of the current journal entry.
+// 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 {
@@ -836,13 +900,16 @@ func (j *Journal) TestCursor(cursor string) error {
 
 	if r < 0 {
 		return fmt.Errorf("failed to test to cursor %q: %d", cursor, syscall.Errno(-r))
+	} else if r == 0 {
+		return ErrNoTestCursor
 	}
 
 	return nil
 }
 
 // SeekHead seeks to the beginning of the journal, i.e. the oldest available
-// entry.
+// 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 {
@@ -861,7 +928,8 @@ func (j *Journal) SeekHead() error {
 }
 
 // SeekTail may be used to seek to the end of the journal, i.e. the most recent
-// available entry.
+// 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 {
@@ -880,7 +948,8 @@ func (j *Journal) SeekTail() error {
 }
 
 // SeekRealtimeUsec seeks to the entry with the specified realtime (wallclock)
-// timestamp, i.e. CLOCK_REALTIME.
+// 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 {
@@ -898,7 +967,9 @@ func (j *Journal) SeekRealtimeUsec(usec uint64) error {
 	return nil
 }
 
-// SeekCursor seeks to a concrete journal cursor.
+// 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 {
@@ -937,7 +1008,7 @@ func (j *Journal) Wait(timeout time.Duration) int {
 		// equivalent hex value.
 		to = 0xffffffffffffffff
 	} else {
-		to = uint64(time.Now().Add(timeout).Unix() / 1000)
+		to = uint64(timeout / time.Microsecond)
 	}
 	j.mu.Lock()
 	r := C.my_sd_journal_wait(sd_journal_wait, j.cjournal, C.uint64_t(to))
@@ -1022,3 +1093,28 @@ func (j *Journal) GetUniqueValues(field string) ([]string, error) {
 
 	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: %d", syscall.Errno(-r))
+	}
+
+	catalog := C.GoString(c)
+
+	return catalog, nil
+}
diff --git a/vendor/github.com/coreos/go-systemd/sdjournal/read.go b/vendor/github.com/coreos/go-systemd/sdjournal/read.go
index b581f03b4..51a060fb5 100644
--- a/vendor/github.com/coreos/go-systemd/sdjournal/read.go
+++ b/vendor/github.com/coreos/go-systemd/sdjournal/read.go
@@ -21,10 +21,13 @@ import (
 	"io"
 	"log"
 	"strings"
+	"sync"
 	"time"
 )
 
 var (
+	// ErrExpired gets returned when the Follow function runs into the
+	// specified timeout.
 	ErrExpired = errors.New("Timeout expired")
 )
 
@@ -44,6 +47,11 @@ type JournalReaderConfig struct {
 	// 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
@@ -51,12 +59,20 @@ type JournalReaderConfig struct {
 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) {
-	r := &JournalReader{}
+	// use simpleMessageFormatter as default formatter.
+	if config.Formatter == nil {
+		config.Formatter = simpleMessageFormatter
+	}
+
+	r := &JournalReader{
+		formatter: config.Formatter,
+	}
 
 	// Open the journal
 	var err error
@@ -71,7 +87,9 @@ func NewJournalReader(config JournalReaderConfig) (*JournalReader, error) {
 
 	// Add any supplied matches
 	for _, m := range config.Matches {
-		r.journal.AddMatch(m.String())
+		if err = r.journal.AddMatch(m.String()); err != nil {
+			return nil, err
+		}
 	}
 
 	// Set the start position based on options
@@ -118,14 +136,10 @@ func NewJournalReader(config JournalReaderConfig) (*JournalReader, error) {
 // 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) {
-	var err error
-
 	if r.msgReader == nil {
-		var c uint64
-
 		// Advance the journal cursor. It has to be called at least one time
 		// before reading
-		c, err = r.journal.Next()
+		c, err := r.journal.Next()
 
 		// An unexpected error
 		if err != nil {
@@ -137,10 +151,13 @@ func (r *JournalReader) Read(b []byte) (int, error) {
 			return 0, io.EOF
 		}
 
-		// Build a message
-		var msg string
-		msg, err = r.buildMessage()
+		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
 		}
@@ -148,8 +165,7 @@ func (r *JournalReader) Read(b []byte) (int, error) {
 	}
 
 	// Copy and return the message
-	var sz int
-	sz, err = r.msgReader.Read(b)
+	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()
@@ -180,80 +196,76 @@ func (r *JournalReader) Rewind() error {
 
 // 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) (err error) {
+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 {
-			break process
+			return err
 		}
 
 		select {
 		case <-until:
 			return ErrExpired
 		default:
-			if c > 0 {
-				if _, err = writer.Write(msg[:c]); err != nil {
-					break process
-				}
-				continue process
+		}
+		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.
-		events := make(chan int, 1)
-		pollDone := make(chan bool, 1)
-		go func() {
-			for {
-				select {
-				case <-pollDone:
-					return
+		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:
-					events <- r.journal.Wait(time.Duration(1) * time.Second)
-				}
-			}
-		}()
+					if e < 0 {
+						return fmt.Errorf("received error event: %d", e)
+					}
 
-		select {
-		case <-until:
-			pollDone <- true
-			return ErrExpired
-		case e := <-events:
-			pollDone <- true
-			switch e {
-			case SD_JOURNAL_NOP, SD_JOURNAL_APPEND, SD_JOURNAL_INVALIDATE:
-				// TODO: need to account for any of these?
-			default:
-				log.Printf("Received unknown event: %d\n", e)
+					log.Printf("received unknown event: %d\n", e)
+				}
 			}
-			continue process
 		}
 	}
-
-	return
 }
 
-// buildMessage returns a string representing the current journal entry in a simple format which
+// 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 (r *JournalReader) buildMessage() (string, error) {
-	var msg string
-	var usec uint64
-	var err error
-
-	if msg, err = r.journal.GetData("MESSAGE"); err != nil {
-		return "", err
-	}
-
-	if usec, err = r.journal.GetRealtimeUsec(); err != nil {
-		return "", err
+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