virtcontainers: add support for getOOMEvent agent endpoint to sandbox

[ port from runtime commit 86686b56a2bf7f6dd62f620278ae289564da51d0 ]

This adds support for the getOOMEvent agent endpoint to retrieve OOM
events from the agent.

Signed-off-by: Alex Price <aprice@atlassian.com>
Signed-off-by: Peng Tao <bergwolf@hyper.sh>

src/runtime/containerd-shim-v2/start.go

@@ -36,6 +36,9 @@ func startContainer(ctx context.Context, s *service, c *container) error {
 			return err
 		}
 		go watchSandbox(s)
+
+		// Start watching for oom events
+		go watchOOMEvents(s)
 	} else {
 		_, err := s.sandbox.StartContainer(c.id)
 		if err != nil {

src/runtime/containerd-shim-v2/start_test.go

@@ -45,6 +45,7 @@ func TestStartStartSandboxSuccess(t *testing.T) {
 		id:         testSandboxID,
 		sandbox:    sandbox,
 		containers: make(map[string]*container),
+		ctx:        namespaces.WithNamespace(context.Background(), "UnitTest"),
 	}
 
 	reqCreate := &taskAPI.CreateTaskRequest{
@@ -93,6 +94,7 @@ func TestStartMissingAnnotation(t *testing.T) {
 		id:         testSandboxID,
 		sandbox:    sandbox,
 		containers: make(map[string]*container),
+		ctx:        namespaces.WithNamespace(context.Background(), "UnitTest"),
 	}
 
 	reqCreate := &taskAPI.CreateTaskRequest{
@@ -113,8 +115,7 @@ func TestStartMissingAnnotation(t *testing.T) {
 		testingImpl.StartSandboxFunc = nil
 	}()
 
-	ctx := namespaces.WithNamespace(context.Background(), "UnitTest")
+	_, err = s.Start(s.ctx, reqStart)
-	_, err = s.Start(ctx, reqStart)
 	assert.Error(err)
 	assert.False(vcmock.IsMockError(err))
 }
@@ -159,6 +160,7 @@ func TestStartStartContainerSucess(t *testing.T) {
 		id:         testSandboxID,
 		sandbox:    sandbox,
 		containers: make(map[string]*container),
+		ctx:        namespaces.WithNamespace(context.Background(), "UnitTest"),
 	}
 
 	reqCreate := &taskAPI.CreateTaskRequest{

src/runtime/containerd-shim-v2/wait.go

@@ -9,6 +9,7 @@ import (
 	"path"
 	"time"
 
+	"github.com/containerd/containerd/api/events"
 	"github.com/containerd/containerd/api/types/task"
 	"github.com/containerd/containerd/mount"
 	"github.com/sirupsen/logrus"
@@ -126,3 +127,26 @@ func watchSandbox(s *service) {
 	// Existing container/exec will be cleaned up by its waiters.
 	// No need to send async events here.
 }
+
+func watchOOMEvents(s *service) {
+	if s.sandbox == nil {
+		return
+	}
+
+	for {
+		select {
+		case <-s.ctx.Done():
+			return
+		default:
+			containerID, err := s.sandbox.GetOOMEvent()
+			if err != nil {
+				logrus.WithError(err).Warn("failed to get oom event from sandbox")
+				continue
+			}
+
+			s.send(&events.TaskOOM{
+				ContainerID: containerID,
+			})
+		}
+	}
+}