Add logging for started supervisor

Signed-off-by: Alexander Morozov <lk4d4@docker.com>

linux/linux.go

@@ -343,6 +343,10 @@ type libcontainerRuntime struct {
 	factory libcontainer.Factory
 }
 
+func (r *libcontainerRuntime) Type() string {
+	return "libcontainer"
+}
+
 func (r *libcontainerRuntime) Create(id, bundlePath string, stdio *runtime.Stdio) (runtime.Container, error) {
 	spec, rspec, err := r.loadSpec(
 		filepath.Join(bundlePath, "config.json"),

runc/runc.go

@@ -135,6 +135,10 @@ type runcRuntime struct {
 	stateDir string
 }
 
+func (r *runcRuntime) Type() string {
+	return "runc"
+}
+
 func (r *runcRuntime) Create(id, bundlePath string, stdio *runtime.Stdio) (runtime.Container, error) {
 	cmd := exec.Command("runc", "--root", r.stateDir, "--id", id, "start")
 	cmd.Dir = bundlePath

runtime/runtime.go

@@ -17,4 +17,5 @@ var (
 type Runtime interface {
 	Create(id, bundlePath string, stdio *Stdio) (Container, error)
 	StartProcess(Container, specs.Process, *Stdio) (Process, error)
+	Type() string
 }

supervisor.go

@@ -149,6 +149,10 @@ func (s *Supervisor) Start() error {
 			close(e.Err)
 		}
 	}()
+	logrus.WithFields(logrus.Fields{
+		"runtime":  s.runtime.Type(),
+		"stateDir": s.stateDir,
+	}).Debug("Supervisor started")
 	return nil
 }