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/virtcontainers/agent.go

@@ -259,4 +259,8 @@ 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)
 }

src/runtime/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

src/runtime/virtcontainers/kata_agent.go

@@ -21,9 +21,9 @@ import (
 	"github.com/kata-containers/kata-containers/src/runtime/virtcontainers/device/api"
 	"github.com/kata-containers/kata-containers/src/runtime/virtcontainers/device/config"
 	persistapi "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/persist/api"
+	aTypes "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/agent/protocols"
 	kataclient "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/agent/protocols/client"
 	"github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/agent/protocols/grpc"
-	aTypes "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/agent/protocols"
 	vcAnnotations "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/annotations"
 	vccgroups "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/cgroups"
 	ns "github.com/kata-containers/kata-containers/src/runtime/virtcontainers/pkg/nsenter"
@@ -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
@@ -2049,6 +2050,9 @@ func (k *kataAgent) installReqFunc(c *kataclient.AgentClient) {
 	k.reqHandlers[grpcStopTracingRequest] = func(ctx context.Context, req interface{}) (interface{}, error) {
 		return k.client.AgentServiceClient.StopTracing(ctx, req.(*grpc.StopTracingRequest))
 	}
+	k.reqHandlers[grpcGetOOMEventRequest] = func(ctx context.Context, req interface{}) (interface{}, error) {
+		return k.client.AgentServiceClient.GetOOMEvent(ctx, req.(*grpc.GetOOMEventRequest))
+	}
 }
 
 func (k *kataAgent) getReqContext(reqName string) (ctx context.Context, cancel context.CancelFunc) {
@@ -2378,3 +2382,16 @@ 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
+}

src/runtime/virtcontainers/kata_agent_test.go

@@ -350,6 +350,9 @@ 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) {

src/runtime/virtcontainers/noop_agent.go

@@ -236,3 +236,7 @@ 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
+}

src/runtime/virtcontainers/noop_agent_test.go

@@ -237,3 +237,12 @@ 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)
+}

src/runtime/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
+}

src/runtime/virtcontainers/sandbox.go

@@ -2201,3 +2201,7 @@ func (s *Sandbox) GetPatchedOCISpec() *specs.Spec {
 
 	return nil
 }
+
+func (s *Sandbox) GetOOMEvent() (string, error) {
+	return s.agent.getOOMEvent()
+}