agent: Fix container creation

Commit bd3c4f844abed063a0d0a8575eb596159f33732c is included through
the new libcontainer vendoring:
    Fix race in runc exec

    There is a race in runc exec when the init process stops just before
    the check for the container status. It is then wrongly assumed that
    we are trying to start an init process instead of an exec process.

    This commit add an Init field to libcontainer Process to distinguish
    between init and exec processes to prevent this race.

In order to prevent from breaking Kata Containers with this commit,
we have to provide explicit information if the process is the init
process or not, depending if we're creating a new container or exec'ing
a process on an existing container.

Signed-off-by: Sebastien Boeuf <[email protected]>

grpc.go

@@ -293,7 +293,7 @@ func setConsoleCarriageReturn(fd int) error {
 	return unix.IoctlSetTermios(fd, unix.TCSETS, termios)
 }
 
-func buildProcess(agentProcess *pb.Process, procID string) (*process, error) {
+func buildProcess(agentProcess *pb.Process, procID string, init bool) (*process, error) {
 	user := agentProcess.User.Username
 	if user == "" {
 		// We can specify the user and the group separated by ":"
@@ -313,6 +313,7 @@ func buildProcess(agentProcess *pb.Process, procID string) (*process, error) {
 			Env:              agentProcess.Env,
 			User:             user,
 			AdditionalGroups: additionalGids,
+			Init:             init,
 		},
 	}
 
@@ -584,7 +585,7 @@ func (a *agentGRPC) finishCreateContainer(ctr *container, req *pb.CreateContaine
 	}
 	ctr.config = *config
 
-	ctr.initProcess, err = buildProcess(req.OCI.Process, req.ExecId)
+	ctr.initProcess, err = buildProcess(req.OCI.Process, req.ExecId, true)
 	if err != nil {
 		return emptyResp, err
 	}
@@ -875,7 +876,7 @@ func (a *agentGRPC) ExecProcess(ctx context.Context, req *pb.ExecProcessRequest)
 		return nil, grpcStatus.Errorf(codes.FailedPrecondition, "Cannot exec in stopped container %s", req.ContainerId)
 	}
 
-	proc, err := buildProcess(req.Process, req.ExecId)
+	proc, err := buildProcess(req.Process, req.ExecId, false)
 	if err != nil {
 		return emptyResp, err
 	}