Merge pull request #43751 from vvoland/fix-exitcode-wait

state/Wait: Fix race when reading exit status

container/container.go

@@ -86,6 +86,7 @@ type Container struct {
 	RestartCount             int
 	HasBeenStartedBefore     bool
 	HasBeenManuallyStopped   bool // used for unless-stopped restart policy
+	HasBeenManuallyRestarted bool `json:"-"` // used to distinguish restart caused by restart policy from the manual one
 	MountPoints              map[string]*volumemounts.MountPoint
 	HostConfig               *containertypes.HostConfig `json:"-"` // do not serialize the host config in the json, otherwise we'll make the container unportable
 	ExecCommands             *exec.Store                `json:"-"`

container/state.go

@@ -32,9 +32,10 @@ type State struct {
 	StartedAt         time.Time
 	FinishedAt        time.Time
 	Health            *Health
+	Removed           bool `json:"-"`
 
-	waitStop   chan struct{}
-	waitRemove chan struct{}
+	stopWaiters       []chan<- StateStatus
+	removeOnlyWaiters []chan<- StateStatus
 }
 
 // StateStatus is used to return container wait results.
@@ -57,12 +58,9 @@ func (s StateStatus) Err() error {
 	return s.err
 }
 
-// NewState creates a default state object with a fresh channel for state changes.
+// NewState creates a default state object.
 func NewState() *State {
-	return &State{
-		waitStop:   make(chan struct{}),
-		waitRemove: make(chan struct{}),
-	}
+	return &State{}
 }
 
 // String returns a human-readable description of the state
@@ -182,11 +180,10 @@ func (s *State) Wait(ctx context.Context, condition WaitCondition) <-chan StateS
 	s.Lock()
 	defer s.Unlock()
 
-	if condition == WaitConditionNotRunning && !s.Running {
-		// Buffer so we can put it in the channel now.
+	// Buffer so we can put status and finish even nobody receives it.
 	resultC := make(chan StateStatus, 1)
 
-		// Send the current status.
+	if s.conditionAlreadyMet(condition) {
 		resultC <- StateStatus{
 			exitCode: s.ExitCode(),
 			err:      s.Err(),
@@ -195,20 +192,17 @@ func (s *State) Wait(ctx context.Context, condition WaitCondition) <-chan StateS
 		return resultC
 	}
 
-	// If we are waiting only for removal, the waitStop channel should
-	// remain nil and block forever.
-	var waitStop chan struct{}
-	if condition < WaitConditionRemoved {
-		waitStop = s.waitStop
+	waitC := make(chan StateStatus, 1)
+
+	// Removal wakes up both removeOnlyWaiters and stopWaiters
+	// Container could be removed while still in "created" state
+	// in which case it is never actually stopped
+	if condition == WaitConditionRemoved {
+		s.removeOnlyWaiters = append(s.removeOnlyWaiters, waitC)
+	} else {
+		s.stopWaiters = append(s.stopWaiters, waitC)
 	}
 
-	// Always wait for removal, just in case the container gets removed
-	// while it is still in a "created" state, in which case it is never
-	// actually stopped.
-	waitRemove := s.waitRemove
-
-	resultC := make(chan StateStatus, 1)
-
 	go func() {
 		select {
 		case <-ctx.Done():
@@ -218,23 +212,25 @@ func (s *State) Wait(ctx context.Context, condition WaitCondition) <-chan StateS
 				err:      ctx.Err(),
 			}
 			return
-		case <-waitStop:
-		case <-waitRemove:
+		case status := <-waitC:
+			resultC <- status
 		}
-
-		s.Lock()
-		result := StateStatus{
-			exitCode: s.ExitCode(),
-			err:      s.Err(),
-		}
-		s.Unlock()
-
-		resultC <- result
 	}()
 
 	return resultC
 }
 
+func (s *State) conditionAlreadyMet(condition WaitCondition) bool {
+	switch condition {
+	case WaitConditionNotRunning:
+		return !s.Running
+	case WaitConditionRemoved:
+		return s.Removed
+	}
+
+	return false
+}
+
 // IsRunning returns whether the running flag is set. Used by Container to check whether a container is running.
 func (s *State) IsRunning() bool {
 	s.Lock()
@@ -292,8 +288,8 @@ func (s *State) SetStopped(exitStatus *ExitStatus) {
 	}
 	s.ExitCodeValue = exitStatus.ExitCode
 	s.OOMKilled = exitStatus.OOMKilled
-	close(s.waitStop) // fire waiters for stop
-	s.waitStop = make(chan struct{})
+
+	s.notifyAndClear(&s.stopWaiters)
 }
 
 // SetRestarting sets the container state to "restarting" without locking.
@@ -308,8 +304,8 @@ func (s *State) SetRestarting(exitStatus *ExitStatus) {
 	s.FinishedAt = time.Now().UTC()
 	s.ExitCodeValue = exitStatus.ExitCode
 	s.OOMKilled = exitStatus.OOMKilled
-	close(s.waitStop) // fire waiters for stop
-	s.waitStop = make(chan struct{})
+
+	s.notifyAndClear(&s.stopWaiters)
 }
 
 // SetError sets the container's error state. This is useful when we want to
@@ -374,22 +370,19 @@ func (s *State) IsDead() bool {
 	return res
 }
 
-// SetRemoved assumes this container is already in the "dead" state and
-// closes the internal waitRemove channel to unblock callers waiting for a
-// container to be removed.
+// SetRemoved assumes this container is already in the "dead" state and notifies all waiters.
 func (s *State) SetRemoved() {
 	s.SetRemovalError(nil)
 }
 
 // SetRemovalError is to be called in case a container remove failed.
-// It sets an error and closes the internal waitRemove channel to unblock
-// callers waiting for the container to be removed.
+// It sets an error and notifies all waiters.
 func (s *State) SetRemovalError(err error) {
 	s.SetError(err)
 	s.Lock()
-	close(s.waitRemove) // Unblock those waiting on remove.
-	// Recreate the channel so next ContainerWait will work
-	s.waitRemove = make(chan struct{})
+	s.Removed = true
+	s.notifyAndClear(&s.removeOnlyWaiters)
+	s.notifyAndClear(&s.stopWaiters)
 	s.Unlock()
 }
 
@@ -400,3 +393,15 @@ func (s *State) Err() error {
 	}
 	return nil
 }
+
+func (s *State) notifyAndClear(waiters *[]chan<- StateStatus) {
+	result := StateStatus{
+		exitCode: s.ExitCodeValue,
+		err:      s.Err(),
+	}
+
+	for _, c := range *waiters {
+		c <- result
+	}
+	*waiters = nil
+}

container/state_test.go

@@ -169,6 +169,31 @@ func TestStateTimeoutWait(t *testing.T) {
 	}
 }
 
+// Related issue: #39352
+func TestCorrectStateWaitResultAfterRestart(t *testing.T) {
+	s := NewState()
+
+	s.Lock()
+	s.SetRunning(0, true)
+	s.Unlock()
+
+	waitC := s.Wait(context.Background(), WaitConditionNotRunning)
+	want := ExitStatus{ExitCode: 10, ExitedAt: time.Now()}
+
+	s.Lock()
+	s.SetRestarting(&want)
+	s.Unlock()
+
+	s.Lock()
+	s.SetRunning(0, true)
+	s.Unlock()
+
+	got := <-waitC
+	if got.exitCode != want.ExitCode {
+		t.Fatalf("expected exit code %v, got %v", want.ExitCode, got.exitCode)
+	}
+}
+
 func TestIsValidStateString(t *testing.T) {
 	states := []struct {
 		state    string

daemon/monitor.go

@@ -52,7 +52,20 @@ func (daemon *Daemon) handleContainerExit(c *container.Container, e *libcontaine
 		}
 	}
 
-	restart, wait, err := c.RestartManager().ShouldRestart(ec, daemon.IsShuttingDown() || c.HasBeenManuallyStopped, time.Since(c.StartedAt))
+	daemonShutdown := daemon.IsShuttingDown()
+	execDuration := time.Since(c.StartedAt)
+	restart, wait, err := c.RestartManager().ShouldRestart(ec, daemonShutdown || c.HasBeenManuallyStopped, execDuration)
+	if err != nil {
+		logrus.WithError(err).
+			WithField("container", c.ID).
+			WithField("restartCount", c.RestartCount).
+			WithField("exitStatus", exitStatus).
+			WithField("daemonShuttingDown", daemonShutdown).
+			WithField("hasBeenManuallyStopped", c.HasBeenManuallyStopped).
+			WithField("execDuration", execDuration).
+			Warn("ShouldRestart failed, container will not be restarted")
+		restart = false
+	}
 
 	// cancel healthcheck here, they will be automatically
 	// restarted if/when the container is started again
@@ -62,13 +75,20 @@ func (daemon *Daemon) handleContainerExit(c *container.Container, e *libcontaine
 	}
 	daemon.Cleanup(c)
 
-	if err == nil && restart {
+	if restart {
 		c.RestartCount++
+		logrus.WithField("container", c.ID).
+			WithField("restartCount", c.RestartCount).
+			WithField("exitStatus", exitStatus).
+			WithField("manualRestart", c.HasBeenManuallyRestarted).
+			Debug("Restarting container")
 		c.SetRestarting(&exitStatus)
 	} else {
 		c.SetStopped(&exitStatus)
+		if !c.HasBeenManuallyRestarted {
 			defer daemon.autoRemove(c)
 		}
+	}
 	defer c.Unlock() // needs to be called before autoRemove
 
 	daemon.setStateCounter(c)
@@ -76,7 +96,7 @@ func (daemon *Daemon) handleContainerExit(c *container.Container, e *libcontaine
 
 	daemon.LogContainerEventWithAttributes(c, "die", attributes)
 
-	if err == nil && restart {
+	if restart {
 		go func() {
 			err := <-wait
 			if err == nil {

daemon/restart.go

@@ -6,7 +6,6 @@ import (
 
 	containertypes "github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/container"
-	"github.com/sirupsen/logrus"
 )
 
 // ContainerRestart stops and starts a container. It attempts to
@@ -52,19 +51,11 @@ func (daemon *Daemon) containerRestart(ctx context.Context, container *container
 	}
 
 	if container.IsRunning() {
-		// set AutoRemove flag to false before stop so the container won't be
-		// removed during restart process
-		autoRemove := container.HostConfig.AutoRemove
+		container.Lock()
+		container.HasBeenManuallyRestarted = true
+		container.Unlock()
 
-		container.HostConfig.AutoRemove = false
 		err := daemon.containerStop(ctx, container, options)
-		// restore AutoRemove irrespective of whether the stop worked or not
-		container.HostConfig.AutoRemove = autoRemove
-		// containerStop will write HostConfig to disk, we shall restore AutoRemove
-		// in disk too
-		if toDiskErr := daemon.checkpointAndSave(container); toDiskErr != nil {
-			logrus.Errorf("Write container to disk error: %v", toDiskErr)
-		}
 
 		if err != nil {
 			return err

daemon/start.go

@@ -206,6 +206,7 @@ func (daemon *Daemon) containerStart(container *container.Container, checkpoint
 		return translateContainerdStartErr(container.Path, container.SetExitCode, err)
 	}
 
+	container.HasBeenManuallyRestarted = false
 	container.SetRunning(pid, true)
 	container.HasBeenStartedBefore = true
 	daemon.setStateCounter(container)

integration/container/restart_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/client"
+	testContainer "github.com/docker/docker/integration/internal/container"
 	"github.com/docker/docker/testutil/daemon"
 	"gotest.tools/v3/assert"
 	"gotest.tools/v3/poll"
@@ -153,3 +154,60 @@ func pollForNewHealthCheck(ctx context.Context, client *client.Client, startTime
 		return poll.Continue("waiting for a new container healthcheck")
 	}
 }
+
+// Container started with --rm should be able to be restarted.
+// It should be removed only if killed or stopped
+func TestContainerWithAutoRemoveCanBeRestarted(t *testing.T) {
+	defer setupTest(t)()
+	cli := testEnv.APIClient()
+	ctx := context.Background()
+
+	noWaitTimeout := 0
+
+	for _, tc := range []struct {
+		desc  string
+		doSth func(ctx context.Context, containerID string) error
+	}{
+		{
+			desc: "kill",
+			doSth: func(ctx context.Context, containerID string) error {
+				return cli.ContainerKill(ctx, containerID, "SIGKILL")
+			},
+		},
+		{
+			desc: "stop",
+			doSth: func(ctx context.Context, containerID string) error {
+				return cli.ContainerStop(ctx, containerID, container.StopOptions{Timeout: &noWaitTimeout})
+			},
+		},
+	} {
+		tc := tc
+		t.Run(tc.desc, func(t *testing.T) {
+			cID := testContainer.Run(ctx, t, cli,
+				testContainer.WithName("autoremove-restart-and-"+tc.desc),
+				testContainer.WithAutoRemove,
+			)
+			defer func() {
+				err := cli.ContainerRemove(ctx, cID, types.ContainerRemoveOptions{Force: true})
+				if t.Failed() && err != nil {
+					t.Logf("Cleaning up test container failed with error: %v", err)
+				}
+			}()
+
+			err := cli.ContainerRestart(ctx, cID, container.StopOptions{Timeout: &noWaitTimeout})
+			assert.NilError(t, err)
+
+			inspect, err := cli.ContainerInspect(ctx, cID)
+			assert.NilError(t, err)
+			assert.Assert(t, inspect.State.Status != "removing", "Container should not be removing yet")
+
+			poll.WaitOn(t, testContainer.IsInState(ctx, cli, cID, "running"))
+
+			err = tc.doSth(ctx, cID)
+			assert.NilError(t, err)
+
+			poll.WaitOn(t, testContainer.IsRemoved(ctx, cli, cID))
+		})
+	}
+
+}

integration/container/wait_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/docker/docker/api/types"
 	containertypes "github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/integration/internal/container"
 	"github.com/docker/docker/testutil/request"
@@ -156,3 +157,69 @@ func TestWaitConditions(t *testing.T) {
 		})
 	}
 }
+
+func TestWaitRestartedContainer(t *testing.T) {
+	defer setupTest(t)()
+	cli := request.NewAPIClient(t)
+
+	testCases := []struct {
+		doc      string
+		waitCond containertypes.WaitCondition
+	}{
+		{
+			doc: "default",
+		},
+		{
+			doc:      "not-running",
+			waitCond: containertypes.WaitConditionNotRunning,
+		},
+		{
+			doc:      "next-exit",
+			waitCond: containertypes.WaitConditionNextExit,
+		},
+	}
+
+	// We can't catch the SIGTERM in the Windows based busybox image
+	isWindowDaemon := testEnv.DaemonInfo.OSType == "windows"
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.doc, func(t *testing.T) {
+			t.Parallel()
+			ctx := context.Background()
+			containerID := container.Run(ctx, t, cli,
+				container.WithCmd("sh", "-c", "trap 'exit 5' SIGTERM; while true; do sleep 0.1; done"),
+			)
+			defer cli.ContainerRemove(ctx, containerID, types.ContainerRemoveOptions{Force: true})
+
+			poll.WaitOn(t, container.IsInState(ctx, cli, containerID, "running"), poll.WithTimeout(30*time.Second), poll.WithDelay(100*time.Millisecond))
+
+			// Container is running now, wait for exit
+			waitResC, errC := cli.ContainerWait(ctx, containerID, tc.waitCond)
+
+			timeout := 5
+			// On Windows it will always timeout, because our process won't receive SIGTERM
+			// Skip to force killing immediately
+			if isWindowDaemon {
+				timeout = 0
+			}
+
+			err := cli.ContainerRestart(ctx, containerID, containertypes.StopOptions{Timeout: &timeout, Signal: "SIGTERM"})
+			assert.NilError(t, err)
+
+			select {
+			case err := <-errC:
+				t.Fatalf("Unexpected error: %v", err)
+			case <-time.After(time.Second * 3):
+				t.Fatalf("Wait should end after restart")
+			case waitRes := <-waitResC:
+				expectedCode := int64(5)
+
+				if !isWindowDaemon {
+					assert.Check(t, is.Equal(expectedCode, waitRes.StatusCode))
+				}
+			}
+		})
+	}
+
+}

integration/internal/container/states.go

@@ -57,3 +57,17 @@ func IsSuccessful(ctx context.Context, client client.APIClient, containerID stri
 		return poll.Continue("waiting for container to be \"exited\", currently %s", inspect.State.Status)
 	}
 }
+
+// IsRemoved verifies the container has been removed
+func IsRemoved(ctx context.Context, cli client.APIClient, containerID string) func(log poll.LogT) poll.Result {
+	return func(log poll.LogT) poll.Result {
+		inspect, err := cli.ContainerInspect(ctx, containerID)
+		if err != nil {
+			if client.IsErrNotFound(err) {
+				return poll.Success()
+			}
+			return poll.Error(err)
+		}
+		return poll.Continue("waiting for container to be removed, currently %s", inspect.State.Status)
+	}
+}