agent: New method stop() for agent interface

This stop method will be used to make sure we stop the connection
with the agent running on the VM, before the hypervisor stop the VM.

In some cases, keeping an opened connection could prevent the hypervisor
from stopping the VM.

In case we want to stop the pod, this means the pod

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

agent.go

@@ -127,4 +127,7 @@ type agent interface {
 
 	// stopPod will tell the agent to stop all containers related to the Pod.
 	stopPod(config PodConfig) error
+
+	// stop will stop the agent on the host.
+	stop() error
 }

hyperstart.go

@@ -498,3 +498,28 @@ func (h *hyper) stopPod(config PodConfig) error {
 
 	return nil
 }
+
+// stop is the agent stopping implementation for hyperstart.
+func (h *hyper) stop() error {
+	if h.cCtl == nil {
+		return fmt.Errorf("Cannot close CTL channel, fd is nil")
+	}
+
+	err := h.cCtl.Close()
+	if err != nil {
+		return err
+	}
+	h.cCtl = nil
+
+	if h.cTty == nil {
+		return fmt.Errorf("Cannot close TTY channel, fd is nil")
+	}
+
+	err = h.cTty.Close()
+	if err != nil {
+		return err
+	}
+	h.cTty = nil
+
+	return nil
+}

noop_agent.go

@@ -45,3 +45,8 @@ func (n *noopAgent) startPod(config PodConfig) error {
 func (n *noopAgent) stopPod(config PodConfig) error {
 	return nil
 }
+
+// stop is the Noop agent stopping implementation. It does nothing.
+func (n *noopAgent) stop() error {
+	return nil
+}

pod.go

@@ -812,6 +812,11 @@ func (p *Pod) stop() error {
 		return err
 	}
 
+	err = p.agent.stop()
+	if err != nil {
+		return err
+	}
+
 	err = p.hypervisor.stopPod()
 	if err != nil {
 		return err

sshd.go

@@ -157,3 +157,8 @@ func (s *sshd) startPod(config PodConfig) error {
 func (s *sshd) stopPod(config PodConfig) error {
 	return nil
 }
+
+// stop is the agent stopping implementation for sshd.
+func (s *sshd) stop() error {
+	return nil
+}