Call start in containerd

This fixes a sync issue when the containerd api returns after a
container has started.  It fixes it by calling the runtime start inside
containerd after the oom handler has been setup.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

containerd-shim/main.go

@@ -136,13 +136,6 @@ func start(log *os.File) error {
 					Height: uint16(msg.Height),
 				}
 				term.SetWinsize(p.console.Fd(), &ws)
-			case 2:
-				// tell runtime to execute the init process
-				if err := p.start(); err != nil {
-					p.delete()
-					p.Wait()
-					return err
-				}
 			}
 		}
 	}

containerd-shim/process.go

@@ -206,26 +206,6 @@ func (p *process) create() error {
 	return nil
 }
 
-func (p *process) start() error {
-	cwd, err := os.Getwd()
-	if err != nil {
-		return err
-	}
-	logPath := filepath.Join(cwd, "log.json")
-	args := append([]string{
-		"--log", logPath,
-		"--log-format", "json",
-	}, p.state.RuntimeArgs...)
-	args = append(args, "start", p.id)
-	cmd := exec.Command(p.runtime, args...)
-	cmd.Dir = p.bundle
-	cmd.Stdin = p.stdio.stdin
-	cmd.Stdout = p.stdio.stdout
-	cmd.Stderr = p.stdio.stderr
-	cmd.SysProcAttr = setPDeathSig()
-	return cmd.Run()
-}
-
 func (p *process) pid() int {
 	return p.containerPid
 }

integration-test/start_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 	"syscall"
 	"time"
@@ -326,6 +327,9 @@ func (cs *ContainerdSuite) TestOOM(t *check.C) {
 		spec.Linux.Resources.Memory = &ocs.Memory{
 			Limit: &limit,
 		}
+		if swapEnabled() {
+			spec.Linux.Resources.Memory.Swap = &limit
+		}
 	}); err != nil {
 		t.Fatal(err)
 	}
@@ -362,7 +366,7 @@ func (cs *ContainerdSuite) TestOOM(t *check.C) {
 			evt.Timestamp = e.Timestamp
 			t.Assert(*e, checker.Equals, evt)
 		case <-time.After(60 * time.Second):
-			t.Fatal("Container took more than 10 seconds to terminate")
+			t.Fatalf("Container took more than 60 seconds to %s", evt.Type)
 		}
 	}
 }
@@ -479,3 +483,8 @@ func (cs *ContainerdSuite) TestRestart(t *check.C) {
 		t.Assert(containers[i].Status, checker.Equals, "running")
 	}
 }
+
+func swapEnabled() bool {
+	_, err := os.Stat("/sys/fs/cgroup/memory/memory.memsw.limit_in_bytes")
+	return err == nil
+}

runtime/process.go

@@ -260,8 +260,33 @@ func (p *process) Signal(s os.Signal) error {
 // This should only be called on the process with ID "init"
 func (p *process) Start() error {
 	if p.ID() == InitProcessID {
-		_, err := fmt.Fprintf(p.controlPipe, "%d %d %d\n", 2, 0, 0)
-		return err
+		var (
+			errC     = make(chan error, 1)
+			shimExit = make(chan struct{}, 1)
+			args     = append(p.container.runtimeArgs, "start", p.container.id)
+			cmd      = exec.Command(p.container.runtime, args...)
+		)
+		go func() {
+			out, err := cmd.CombinedOutput()
+			if err != nil {
+				errC <- fmt.Errorf("%s: %q", err.Error(), out)
+			}
+			errC <- nil
+		}()
+		go func() {
+			p.Wait()
+			close(shimExit)
+		}()
+		select {
+		case err := <-errC:
+			if err != nil {
+				return err
+			}
+		case <-shimExit:
+			cmd.Process.Kill()
+			cmd.Wait()
+			return ErrShimExited
+		}
 	}
 	return nil
 }

runtime/runtime.go

@@ -20,6 +20,9 @@ var (
 	// ErrContainerStartTimeout is returned if a container takes too
 	// long to start
 	ErrContainerStartTimeout = errors.New("containerd: container did not start before the specified timeout")
+	// ErrShimExited is returned if the shim or the contianer's init process
+	// exits before completing
+	ErrShimExited = errors.New("containerd: shim exited before container process was started")
 
 	errNoPidFile      = errors.New("containerd: no process pid file found")
 	errInvalidPidInt  = errors.New("containerd: process pid is invalid")

supervisor/worker.go

@@ -62,9 +62,23 @@ func (w *worker) Start() {
 		}
 		if err := w.s.monitorProcess(process); err != nil {
 			logrus.WithField("error", err).Error("containerd: add process to monitor")
+			t.Err <- err
+			evt := &DeleteTask{
+				ID:      t.Container.ID(),
+				NoEvent: true,
+			}
+			w.s.SendTask(evt)
+			continue
 		}
 		if err := process.Start(); err != nil {
 			logrus.WithField("error", err).Error("containerd: start init process")
+			t.Err <- err
+			evt := &DeleteTask{
+				ID:      t.Container.ID(),
+				NoEvent: true,
+			}
+			w.s.SendTask(evt)
+			continue
 		}
 		ContainerStartTimer.UpdateSince(started)
 		t.Err <- nil