From d252100c946ff7fd581197d636ed7966b11e9a83 Mon Sep 17 00:00:00 2001
From: baude <bbaude@redhat.com>
Date: Sun, 7 Jul 2019 08:09:48 -0500
Subject: [PATCH] get last container event

an internal change in libpod will soon required the ability to lookup
the last container event using the continer name or id and the type of
event.  this pr is in preperation for that need.

Signed-off-by: baude <bbaude@redhat.com>
---
 libpod/events.go               | 55 ++++++++++++++++++++++++++++++++++
 libpod/events/config.go        | 11 +++++++
 libpod/events/events.go        |  2 ++
 libpod/events/journal_linux.go |  4 ++-
 4 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/libpod/events.go b/libpod/events.go
index 13bb5bdde4..be21e510ad 100644
--- a/libpod/events.go
+++ b/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
+}
diff --git a/libpod/events/config.go b/libpod/events/config.go
index 810988205c..b9f01f3a59 100644
--- a/libpod/events/config.go
+++ b/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")
+)
diff --git a/libpod/events/events.go b/libpod/events/events.go
index 1ec79bcd7f..2bebff1624 100644
--- a/libpod/events/events.go
+++ b/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)
 }
diff --git a/libpod/events/journal_linux.go b/libpod/events/journal_linux.go
index 78a630e9aa..d5bce4334d 100644
--- a/libpod/events/journal_linux.go
+++ b/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