Merge pull request #3505 from baude/getlastevent

get last container event

libpod/events.go

@@ -1,7 +1,10 @@
 package libpod
 
 import (
+	"fmt"
+
 	"github.com/containers/libpod/libpod/events"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
@@ -79,3 +82,55 @@ func (r *Runtime) Events(options events.ReadOptions) error {
 	}
 	return eventer.Read(options)
 }
+
+// GetEvents reads the event log and returns events based on input filters
+func (r *Runtime) GetEvents(filters []string) ([]*events.Event, error) {
+	var (
+		logEvents []*events.Event
+		readErr   error
+	)
+	eventChannel := make(chan *events.Event)
+	options := events.ReadOptions{
+		EventChannel: eventChannel,
+		Filters:      filters,
+		FromStart:    true,
+		Stream:       false,
+	}
+	eventer, err := r.newEventer()
+	if err != nil {
+		return nil, err
+	}
+	go func() {
+		readErr = eventer.Read(options)
+	}()
+	if readErr != nil {
+		return nil, readErr
+	}
+	for e := range eventChannel {
+		logEvents = append(logEvents, e)
+	}
+	return logEvents, nil
+}
+
+// GetLastContainerEvent takes a container name or ID and an event status and returns
+// the last occurrence of the container event
+func (r *Runtime) GetLastContainerEvent(nameOrID string, containerEvent events.Status) (*events.Event, error) {
+	// check to make sure the event.Status is valid
+	if _, err := events.StringToStatus(containerEvent.String()); err != nil {
+		return nil, err
+	}
+	filters := []string{
+		fmt.Sprintf("container=%s", nameOrID),
+		fmt.Sprintf("event=%s", containerEvent),
+		"type=container",
+	}
+	containerEvents, err := r.GetEvents(filters)
+	if err != nil {
+		return nil, err
+	}
+	if len(containerEvents) < 1 {
+		return nil, errors.Wrapf(events.ErrEventNotFound, "%s not found", containerEvent.String())
+	}
+	// return the last element in the slice
+	return containerEvents[len(containerEvents)-1], nil
+}

libpod/events/config.go

@@ -2,6 +2,8 @@ package events
 
 import (
 	"time"
+
+	"github.com/pkg/errors"
 )
 
 // EventerType ...
@@ -158,3 +160,12 @@ const (
 
 // EventFilter for filtering events
 type EventFilter func(*Event) bool
+
+var (
+	// ErrEventTypeBlank indicates the event log found something done by podman
+	// but it isnt likely an event
+	ErrEventTypeBlank = errors.New("event type blank")
+
+	// ErrEventNotFound indicates that the event was not found in the event log
+	ErrEventNotFound = errors.New("unable to find event")
+)

libpod/events/events.go

@@ -95,6 +95,8 @@ func StringToType(name string) (Type, error) {
 		return System, nil
 	case Volume.String():
 		return Volume, nil
+	case "":
+		return "", ErrEventTypeBlank
 	}
 	return "", errors.Errorf("unknown event type %q", name)
 }

libpod/events/journal_linux.go

@@ -101,7 +101,9 @@ func (e EventJournalD) Read(options ReadOptions) error {
 			// We can't decode this event.
 			// Don't fail hard - that would make events unusable.
 			// Instead, log and continue.
-			logrus.Errorf("Unable to decode event: %v", err)
+			if errors.Cause(err) != ErrEventTypeBlank {
+				logrus.Errorf("Unable to decode event: %v", err)
+			}
 			continue
 		}
 		include := true