Add event logging to libpod, even display to podman

In lipod, we now log major events that occurr.  These events
can be displayed using the `podman events` command. Each
event contains:

* Type (container, image, volume, pod...)
* Status (create, rm, stop, kill, ....)
* Timestamp in RFC3339Nano format
* Name (if applicable)
* Image (if applicable)

The format of the event and the varlink endpoint are to not
be considered stable until cockpit has done its enablement.

Signed-off-by: baude <bbaude@redhat.com>

4 files changed, 200 insertions, 0 deletions

diff --git a/pkg/adapter/runtime.go b/pkg/adapter/runtime.go
index 482b6119a..a0951f677 100644
--- a/pkg/adapter/runtime.go
+++ b/pkg/adapter/runtime.go
@@ -3,11 +3,13 @@
 package adapter
 
 import (
+	"bufio"
 	"context"
 	"io"
 	"io/ioutil"
 	"os"
 	"strconv"
+	"text/template"
 
 	"github.com/containers/buildah"
 	"github.com/containers/buildah/imagebuildah"
@@ -16,7 +18,9 @@ import (
 	"github.com/containers/image/types"
 	"github.com/containers/libpod/cmd/podman/cliconfig"
 	"github.com/containers/libpod/cmd/podman/libpodruntime"
+	"github.com/containers/libpod/cmd/podman/shared"
 	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/libpod/events"
 	"github.com/containers/libpod/libpod/image"
 	"github.com/containers/libpod/pkg/rootless"
 	"github.com/pkg/errors"
@@ -377,3 +381,52 @@ func (r *LocalRuntime) JoinOrCreateRootlessPod(pod *Pod) (bool, int, error) {
 
 	return rootless.BecomeRootInUserNSWithOpts(&opts)
 }
+
+// Events is a wrapper to libpod to obtain libpod/podman events
+func (r *LocalRuntime) Events(c *cliconfig.EventValues) error {
+	var (
+		fromStart   bool
+		eventsError error
+	)
+	options, err := shared.GenerateEventOptions(c.Filter, c.Since, c.Until)
+	if err != nil {
+		return errors.Wrapf(err, "unable to generate event options")
+	}
+	tmpl, err := template.New("events").Parse(c.Format)
+	if err != nil {
+		return err
+	}
+	if len(c.Since) > 0 || len(c.Until) > 0 {
+		fromStart = true
+	}
+	eventChannel := make(chan *events.Event)
+	go func() {
+		eventsError = r.Runtime.Events(fromStart, c.Stream, options, eventChannel)
+	}()
+
+	if eventsError != nil {
+		return eventsError
+	}
+	if err != nil {
+		return errors.Wrapf(err, "unable to tail the events log")
+	}
+	w := bufio.NewWriter(os.Stdout)
+	for event := range eventChannel {
+		if len(c.Format) > 0 {
+			if err := tmpl.Execute(w, event); err != nil {
+				return err
+			}
+		} else {
+			if _, err := w.Write([]byte(event.ToHumanReadable())); err != nil {
+				return err
+			}
+		}
+		if _, err := w.Write([]byte("\n")); err != nil {
+			return err
+		}
+		if err := w.Flush(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/pkg/adapter/runtime_remote.go b/pkg/adapter/runtime_remote.go
index 9ca4e245f..01f774dbd 100644
--- a/pkg/adapter/runtime_remote.go
+++ b/pkg/adapter/runtime_remote.go
@@ -10,6 +10,7 @@ import (
 	"io/ioutil"
 	"os"
 	"strings"
+	"text/template"
 	"time"
 
 	"github.com/containers/buildah/imagebuildah"
@@ -18,6 +19,7 @@ import (
 	"github.com/containers/libpod/cmd/podman/cliconfig"
 	"github.com/containers/libpod/cmd/podman/varlink"
 	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/libpod/events"
 	"github.com/containers/libpod/libpod/image"
 	"github.com/containers/libpod/utils"
 	"github.com/containers/storage/pkg/archive"
@@ -758,3 +760,69 @@ func (r *LocalRuntime) JoinOrCreateRootlessPod(pod *Pod) (bool, int, error) {
 	// Nothing to do in the remote case
 	return true, 0, nil
 }
+
+// Events monitors libpod/podman events over a varlink connection
+func (r *LocalRuntime) Events(c *cliconfig.EventValues) error {
+	reply, err := iopodman.GetEvents().Send(r.Conn, uint64(varlink.More), c.Filter, c.Since, c.Stream, c.Until)
+	if err != nil {
+		return errors.Wrapf(err, "unable to obtain events")
+	}
+
+	w := bufio.NewWriter(os.Stdout)
+	tmpl, err := template.New("events").Parse(c.Format)
+	if err != nil {
+		return err
+	}
+
+	for {
+		returnedEvent, flags, err := reply()
+		if err != nil {
+			// When the error handling is back into podman, we can flip this to a better way to check
+			// for problems. For now, this works.
+			return err
+		}
+		if returnedEvent.Time == "" && returnedEvent.Status == "" && returnedEvent.Type == "" {
+			// We got a blank event return, signals end of stream in certain cases
+			break
+		}
+		eTime, err := time.Parse(time.RFC3339Nano, returnedEvent.Time)
+		if err != nil {
+			return errors.Wrapf(err, "unable to parse time of event %s", returnedEvent.Time)
+		}
+		eType, err := events.StringToType(returnedEvent.Type)
+		if err != nil {
+			return err
+		}
+		eStatus, err := events.StringToStatus(returnedEvent.Status)
+		if err != nil {
+			return err
+		}
+		event := events.Event{
+			ID:     returnedEvent.Id,
+			Image:  returnedEvent.Image,
+			Name:   returnedEvent.Name,
+			Status: eStatus,
+			Time:   eTime,
+			Type:   eType,
+		}
+		if len(c.Format) > 0 {
+			if err := tmpl.Execute(w, event); err != nil {
+				return err
+			}
+		} else {
+			if _, err := w.Write([]byte(event.ToHumanReadable())); err != nil {
+				return err
+			}
+		}
+		if _, err := w.Write([]byte("\n")); err != nil {
+			return err
+		}
+		if err := w.Flush(); err != nil {
+			return err
+		}
+		if flags&varlink.Continues == 0 {
+			break
+		}
+	}
+	return nil
+}
diff --git a/pkg/util/utils.go b/pkg/util/utils.go
index a4576191b..d7e1ddd38 100644
--- a/pkg/util/utils.go
+++ b/pkg/util/utils.go
@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"strings"
 	"syscall"
+	"time"
 
 	"github.com/BurntSushi/toml"
 	"github.com/containers/image/types"
@@ -347,3 +348,25 @@ func StorageConfigFile() string {
 	}
 	return storage.DefaultConfigFile
 }
+
+// ParseInputTime takes the users input and to determine if it is valid and
+// returns a time format and error.  The input is compared to known time formats
+// or a duration which implies no-duration
+func ParseInputTime(inputTime string) (time.Time, error) {
+	timeFormats := []string{time.RFC3339Nano, time.RFC3339, "2006-01-02T15:04:05", "2006-01-02T15:04:05.999999999",
+		"2006-01-02Z07:00", "2006-01-02"}
+	// iterate the supported time formats
+	for _, tf := range timeFormats {
+		t, err := time.Parse(tf, inputTime)
+		if err == nil {
+			return t, nil
+		}
+	}
+
+	// input might be a duration
+	duration, err := time.ParseDuration(inputTime)
+	if err != nil {
+		return time.Time{}, errors.Errorf("unable to interpret time value")
+	}
+	return time.Now().Add(-duration), nil
+}
diff --git a/pkg/varlinkapi/events.go b/pkg/varlinkapi/events.go
new file mode 100644
index 000000000..d3fe3d65f
--- /dev/null
+++ b/pkg/varlinkapi/events.go
@@ -0,0 +1,56 @@
+package varlinkapi
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/containers/libpod/cmd/podman/shared"
+	"github.com/containers/libpod/cmd/podman/varlink"
+	"github.com/containers/libpod/libpod/events"
+)
+
+// GetEvents is a remote endpoint to get events from the event log
+func (i *LibpodAPI) GetEvents(call iopodman.VarlinkCall, filter []string, since string, stream bool, until string) error {
+	var (
+		fromStart   bool
+		eventsError error
+		event       *events.Event
+	)
+	if call.WantsMore() {
+		call.Continues = true
+	}
+	filters, err := shared.GenerateEventOptions(filter, since, until)
+	if err != nil {
+		return call.ReplyErrorOccurred(err.Error())
+	}
+	if len(since) > 0 || len(until) > 0 {
+		fromStart = true
+	}
+	eventChannel := make(chan *events.Event)
+	go func() {
+		eventsError = i.Runtime.Events(fromStart, stream, filters, eventChannel)
+	}()
+	if eventsError != nil {
+		return call.ReplyErrorOccurred(err.Error())
+	}
+	for {
+		event = <-eventChannel
+		if event == nil {
+			call.Continues = false
+			break
+		}
+		call.ReplyGetEvents(iopodman.Event{
+			Id:     event.ID,
+			Image:  event.Image,
+			Name:   event.Name,
+			Status: fmt.Sprintf("%s", event.Status),
+			Time:   event.Time.Format(time.RFC3339Nano),
+			Type:   fmt.Sprintf("%s", event.Type),
+		})
+		if !call.Continues {
+			// For a one-shot on events, we break out here
+			break
+		}
+	}
+	return call.ReplyGetEvents(iopodman.Event{})
+}