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>

2 files changed, 121 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
+}