virtcontainers: add support for getOOMEvent agent endpoint to sandbox

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

Signed-off-by: Alex Price <[email protected]>

virtcontainers/agent.go

@@ -262,4 +262,8 @@ type agent interface {
 
 	// load data from disk
 	load(persistapi.AgentState)
+
+	// getOOMEvent will wait on OOM events that occur in the sandbox.
+	// Will return the ID of the container where the event occurred.
+	getOOMEvent() (string, error)
 }

virtcontainers/interfaces.go

@@ -98,6 +98,8 @@ type VCSandbox interface {
 	ListInterfaces() ([]*vcTypes.Interface, error)
 	UpdateRoutes(routes []*vcTypes.Route) ([]*vcTypes.Route, error)
 	ListRoutes() ([]*vcTypes.Route, error)
+
+	GetOOMEvent() (string, error)
 }
 
 // VCContainer is the Container interface

virtcontainers/kata_agent.go

@@ -127,6 +127,7 @@ const (
 	grpcSetGuestDateTimeRequest  = "grpc.SetGuestDateTimeRequest"
 	grpcStartTracingRequest      = "grpc.StartTracingRequest"
 	grpcStopTracingRequest       = "grpc.StopTracingRequest"
+	grpcGetOOMEventRequest       = "grpc.GetOOMEventRequest"
 )
 
 // The function is declared this way for mocking in unit tests
@@ -1989,6 +1990,9 @@ func (k *kataAgent) installReqFunc(c *kataclient.AgentClient) {
 	k.reqHandlers[grpcStopTracingRequest] = func(ctx context.Context, req interface{}, opts ...golangGrpc.CallOption) (interface{}, error) {
 		return k.client.StopTracing(ctx, req.(*grpc.StopTracingRequest), opts...)
 	}
+	k.reqHandlers[grpcGetOOMEventRequest] = func(ctx context.Context, req interface{}, opts ...golangGrpc.CallOption) (interface{}, error) {
+		return k.client.GetOOMEvent(ctx, req.(*grpc.GetOOMEventRequest), opts...)
+	}
 }
 
 func (k *kataAgent) getReqContext(reqName string) (ctx context.Context, cancel context.CancelFunc) {
@@ -2311,3 +2315,16 @@ func (k *kataAgent) load(s persistapi.AgentState) {
 	k.state.ProxyPid = s.ProxyPid
 	k.state.URL = s.URL
 }
+
+func (k *kataAgent) getOOMEvent() (string, error) {
+	req := &grpc.GetOOMEventRequest{}
+	result, err := k.sendReq(req)
+	if err != nil {
+		return "", err
+	}
+	oomEvent, ok := result.(*grpc.OOMEvent)
+	if ok {
+		return oomEvent.ContainerId, err
+	}
+	return "", err
+}

virtcontainers/kata_agent_test.go

@@ -246,6 +246,10 @@ func (p *gRPCProxy) MemHotplugByProbe(ctx context.Context, req *pb.MemHotplugByP
 	return &gpb.Empty{}, nil
 }
 
+func (p *gRPCProxy) GetOOMEvent(ctx context.Context, req *pb.GetOOMEventRequest) (*pb.OOMEvent, error) {
+	return &pb.OOMEvent{}, nil
+}
+
 func gRPCRegister(s *grpc.Server, srv interface{}) {
 	switch g := srv.(type) {
 	case *gRPCProxy:
@@ -347,6 +351,9 @@ func TestKataAgentSendReq(t *testing.T) {
 
 	_, err = k.readProcessStderr(container, execid, []byte{})
 	assert.Nil(err)
+
+	_, err = k.getOOMEvent()
+	assert.Nil(err)
 }
 
 func TestHandleEphemeralStorage(t *testing.T) {

virtcontainers/noop_agent.go

@@ -241,3 +241,7 @@ func (n *noopAgent) save() (s persistapi.AgentState) {
 
 // load is the Noop agent state loader. It does nothing.
 func (n *noopAgent) load(s persistapi.AgentState) {}
+
+func (n *noopAgent) getOOMEvent() (string, error) {
+	return "", nil
+}

virtcontainers/noop_agent_test.go

@@ -244,3 +244,12 @@ func TestNoopCopyFile(t *testing.T) {
 	err := n.copyFile("", "")
 	assert.Nil(err)
 }
+
+func TestNoopGetOOMEvent(t *testing.T) {
+	assert := assert.New(t)
+	n := &noopAgent{}
+
+	containerID, err := n.getOOMEvent()
+	assert.Nil(err)
+	assert.Empty(containerID)
+}

virtcontainers/pkg/vcmock/sandbox.go

@@ -212,3 +212,7 @@ func (s *Sandbox) UpdateRoutes(routes []*vcTypes.Route) ([]*vcTypes.Route, error
 func (s *Sandbox) ListRoutes() ([]*vcTypes.Route, error) {
 	return nil, nil
 }
+
+func (s *Sandbox) GetOOMEvent() (string, error) {
+	return "", nil
+}

virtcontainers/sandbox.go

@@ -2178,3 +2178,7 @@ func (s *Sandbox) GetPatchedOCISpec() *specs.Spec {
 
 	return nil
 }
+
+func (s *Sandbox) GetOOMEvent() (string, error) {
+	return s.agent.getOOMEvent()
+}