Merge pull request #1989 from crosbymichael/reaper

Remove reaper from containerd daemon

cmd/containerd/config_linux.go

@@ -12,7 +12,6 @@ func defaultConfig() *server.Config {
 		GRPC: server.GRPCConfig{
 			Address: defaults.DefaultAddress,
 		},
-		NoSubreaper: false,
 		Debug: server.Debug{
 			Level:   "info",
 			Address: defaults.DefaultDebugAddress,

cmd/containerd/main_unix.go

@@ -11,7 +11,6 @@ import (
 	"golang.org/x/sys/unix"
 
 	"github.com/containerd/containerd/log"
-	"github.com/containerd/containerd/reaper"
 	"github.com/containerd/containerd/server"
 )
 
@@ -21,7 +20,6 @@ var handledSignals = []os.Signal{
 	unix.SIGTERM,
 	unix.SIGINT,
 	unix.SIGUSR1,
-	unix.SIGCHLD,
 	unix.SIGPIPE,
 }
 
@@ -36,10 +34,6 @@ func handleSignals(ctx context.Context, signals chan os.Signal, serverC chan *se
 			case s := <-signals:
 				log.G(ctx).WithField("signal", s).Debug("received signal")
 				switch s {
-				case unix.SIGCHLD:
-					if err := reaper.Reap(); err != nil {
-						log.G(ctx).WithError(err).Error("reap containerd processes")
-					}
 				case unix.SIGUSR1:
 					dumpStacks()
 				case unix.SIGPIPE:

linux/runtime.go

@@ -26,9 +26,7 @@ import (
 	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/plugin"
-	"github.com/containerd/containerd/reaper"
 	"github.com/containerd/containerd/runtime"
-	"github.com/containerd/containerd/sys"
 	runc "github.com/containerd/go-runc"
 	"github.com/containerd/typeurl"
 	ptypes "github.com/gogo/protobuf/types"
@@ -159,9 +157,6 @@ func (r *Runtime) Create(ctx context.Context, id string, opts runtime.CreateOpts
 		return nil, err
 	}
 
-	ec := reaper.Default.Subscribe()
-	defer reaper.Default.Unsubscribe(ec)
-
 	bundle, err := newBundle(id,
 		filepath.Join(r.state, namespace),
 		filepath.Join(r.root, namespace),
@@ -206,7 +201,7 @@ func (r *Runtime) Create(ctx context.Context, id string, opts runtime.CreateOpts
 				"id":        id,
 				"namespace": namespace,
 			}).Warn("cleaning up after killed shim")
-			err = r.cleanupAfterDeadShim(context.Background(), bundle, namespace, id, lc.pid, ec)
+			err = r.cleanupAfterDeadShim(context.Background(), bundle, namespace, id, lc.pid)
 			if err == nil {
 				r.tasks.Delete(ctx, lc)
 			} else {
@@ -313,7 +308,7 @@ func (r *Runtime) Delete(ctx context.Context, c runtime.Task) (*runtime.Exit, er
 
 	rsp, err := lc.shim.Delete(ctx, empty)
 	if err != nil {
-		if cerr := r.cleanupAfterDeadShim(ctx, bundle, namespace, c.ID(), lc.pid, nil); cerr != nil {
+		if cerr := r.cleanupAfterDeadShim(ctx, bundle, namespace, c.ID(), lc.pid); cerr != nil {
 			log.G(ctx).WithError(err).Error("unable to cleanup task")
 		}
 		return nil, errdefs.FromGRPC(err)
@@ -394,7 +389,7 @@ func (r *Runtime) loadTasks(ctx context.Context, ns string) ([]*Task, error) {
 				"id":        id,
 				"namespace": ns,
 			}).Error("connecting to shim")
-			err := r.cleanupAfterDeadShim(ctx, bundle, ns, id, pid, nil)
+			err := r.cleanupAfterDeadShim(ctx, bundle, ns, id, pid)
 			if err != nil {
 				log.G(ctx).WithError(err).WithField("bundle", bundle.path).
 					Error("cleaning up after dead shim")
@@ -419,7 +414,7 @@ func (r *Runtime) loadTasks(ctx context.Context, ns string) ([]*Task, error) {
 	return o, nil
 }
 
-func (r *Runtime) cleanupAfterDeadShim(ctx context.Context, bundle *bundle, ns, id string, pid int, ec chan runc.Exit) error {
+func (r *Runtime) cleanupAfterDeadShim(ctx context.Context, bundle *bundle, ns, id string, pid int) error {
 	ctx = namespaces.WithNamespace(ctx, ns)
 	if err := r.terminate(ctx, bundle, ns, id); err != nil {
 		if r.config.ShimDebug {
@@ -428,17 +423,6 @@ func (r *Runtime) cleanupAfterDeadShim(ctx context.Context, bundle *bundle, ns,
 		log.G(ctx).WithError(err).Warn("failed to terminate task")
 	}
 
-	if ec != nil {
-		// if sub-reaper is set, reap our new child
-		if v, err := sys.GetSubreaper(); err == nil && v == 1 {
-			for e := range ec {
-				if e.Pid == pid {
-					break
-				}
-			}
-		}
-	}
-
 	// Notify Client
 	exitedAt := time.Now().UTC()
 	r.events.Publish(ctx, runtime.TaskExitEventTopic, &eventstypes.TaskExit{

linux/shim/client/client.go

@@ -23,7 +23,6 @@ import (
 	"github.com/containerd/containerd/linux/shim"
 	shimapi "github.com/containerd/containerd/linux/shim/v1"
 	"github.com/containerd/containerd/log"
-	"github.com/containerd/containerd/reaper"
 	"github.com/containerd/containerd/sys"
 	ptypes "github.com/gogo/protobuf/types"
 )
@@ -51,8 +50,7 @@ func WithStart(binary, address, daemonAddress, cgroup string, debug bool, exitHa
 		if err != nil {
 			return nil, nil, err
 		}
-		ec, err := reaper.Default.Start(cmd)
-		if err != nil {
+		if err := cmd.Start(); err != nil {
 			return nil, nil, errors.Wrapf(err, "failed to start shim")
 		}
 		defer func() {
@@ -61,7 +59,7 @@ func WithStart(binary, address, daemonAddress, cgroup string, debug bool, exitHa
 			}
 		}()
 		go func() {
-			reaper.Default.Wait(cmd, ec)
+			cmd.Wait()
 			exitHandler()
 		}()
 		log.G(ctx).WithFields(logrus.Fields{

server/config.go

@@ -23,8 +23,6 @@ type Config struct {
 	Metrics MetricsConfig `toml:"metrics"`
 	// Plugins provides plugin specific configuration for the initialization of a plugin
 	Plugins map[string]toml.Primitive `toml:"plugins"`
-	// NoSubreaper disables containerd as a subreaper
-	NoSubreaper bool `toml:"no_subreaper"`
 	// OOMScore adjust the containerd's oom score
 	OOMScore int `toml:"oom_score"`
 	// Cgroup specifies cgroup information for the containerd daemon process

server/server_linux.go

@@ -12,12 +12,6 @@ import (
 
 // apply sets config settings on the server process
 func apply(ctx context.Context, config *Config) error {
-	if !config.NoSubreaper {
-		log.G(ctx).Info("setting subreaper...")
-		if err := sys.SetSubreaper(1); err != nil {
-			return err
-		}
-	}
 	if config.OOMScore != 0 {
 		log.G(ctx).Debugf("changing OOM score to %d", config.OOMScore)
 		if err := sys.SetOOMScore(os.Getpid(), config.OOMScore); err != nil {