sandbox: Export Start() to the API level

In order to support use cases such as containerd-shim-v2 where we
would have a long running process holding the sandbox pointer, there
would be no reason to call into the stateless function StartSandbox(),
which would recreate a new sandbox pointer and the corresponding ones
for containers.

Fixes #903

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

virtcontainers/api.go

@@ -232,7 +232,7 @@ func StartSandbox(ctx context.Context, sandboxID string) (VCSandbox, error) {
 
 func startSandbox(s *Sandbox) (*Sandbox, error) {
 	// Start it
-	err := s.start()
+	err := s.Start()
 	if err != nil {
 		return nil, err
 	}

virtcontainers/interfaces.go

@@ -66,6 +66,7 @@ type VCSandbox interface {
 	ID() string
 	SetAnnotations(annotations map[string]string) error
 
+	Start() error
 	Pause() error
 	Resume() error
 	Release() error

virtcontainers/pkg/vcmock/sandbox.go

@@ -67,6 +67,11 @@ func (s *Sandbox) Release() error {
 	return nil
 }
 
+// Start implements the VCSandbox function of the same name.
+func (s *Sandbox) Start() error {
+	return nil
+}
+
 // Pause implements the VCSandbox function of the same name.
 func (s *Sandbox) Pause() error {
 	return nil

virtcontainers/sandbox.go

@@ -1442,9 +1442,9 @@ func (s *Sandbox) createContainers() error {
 	return nil
 }
 
-// start starts a sandbox. The containers that are making the sandbox
+// Start starts a sandbox. The containers that are making the sandbox
 // will be started.
-func (s *Sandbox) start() error {
+func (s *Sandbox) Start() error {
 	if err := s.state.validTransition(s.state.State, StateRunning); err != nil {
 		return err
 	}

virtcontainers/sandbox_test.go

@@ -1345,7 +1345,7 @@ func TestStartContainer(t *testing.T) {
 	_, err = s.StartContainer(contID)
 	assert.NotNil(t, err, "Starting non-existing container should fail")
 
-	err = s.start()
+	err = s.Start()
 	assert.Nil(t, err, "Failed to start sandbox: %v", err)
 
 	contConfig := newTestContainerConfigNoop(contID)
@@ -1401,7 +1401,7 @@ func TestEnterContainer(t *testing.T) {
 	_, _, err = s.EnterContainer(contID, cmd)
 	assert.NotNil(t, err, "Entering non-running container should fail")
 
-	err = s.start()
+	err = s.Start()
 	assert.Nil(t, err, "Failed to start sandbox: %v", err)
 
 	_, _, err = s.EnterContainer(contID, cmd)
@@ -1416,7 +1416,7 @@ func TestMonitor(t *testing.T) {
 	_, err = s.Monitor()
 	assert.NotNil(t, err, "Monitoring non-running container should fail")
 
-	err = s.start()
+	err = s.Start()
 	assert.Nil(t, err, "Failed to start sandbox: %v", err)
 
 	_, err = s.Monitor()
@@ -1438,7 +1438,7 @@ func TestWaitProcess(t *testing.T) {
 	_, err = s.WaitProcess(contID, execID)
 	assert.NotNil(t, err, "Wait process in stopped sandbox should fail")
 
-	err = s.start()
+	err = s.Start()
 	assert.Nil(t, err, "Failed to start sandbox: %v", err)
 
 	_, err = s.WaitProcess(contID, execID)
@@ -1468,7 +1468,7 @@ func TestSignalProcess(t *testing.T) {
 	err = s.SignalProcess(contID, execID, syscall.SIGKILL, true)
 	assert.NotNil(t, err, "Wait process in stopped sandbox should fail")
 
-	err = s.start()
+	err = s.Start()
 	assert.Nil(t, err, "Failed to start sandbox: %v", err)
 
 	err = s.SignalProcess(contID, execID, syscall.SIGKILL, false)
@@ -1498,7 +1498,7 @@ func TestWinsizeProcess(t *testing.T) {
 	err = s.WinsizeProcess(contID, execID, 100, 200)
 	assert.NotNil(t, err, "Winsize process in stopped sandbox should fail")
 
-	err = s.start()
+	err = s.Start()
 	assert.Nil(t, err, "Failed to start sandbox: %v", err)
 
 	err = s.WinsizeProcess(contID, execID, 100, 200)
@@ -1528,7 +1528,7 @@ func TestContainerProcessIOStream(t *testing.T) {
 	_, _, _, err = s.IOStream(contID, execID)
 	assert.NotNil(t, err, "Winsize process in stopped sandbox should fail")
 
-	err = s.start()
+	err = s.Start()
 	assert.Nil(t, err, "Failed to start sandbox: %v", err)
 
 	_, _, _, err = s.IOStream(contID, execID)