api/types/container: make ContainerState a concrete type

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

api/types/container/state.go

@@ -6,9 +6,7 @@ import (
 )
 
 // ContainerState is a string representation of the container's current state.
-//
-// It currently is an alias for string, but may become a distinct type in the future.
-type ContainerState = string
+type ContainerState string
 
 const (
 	StateCreated    ContainerState = "created"    // StateCreated indicates the container is created, but not (yet) started.
@@ -20,8 +18,14 @@ const (
 	StateDead       ContainerState = "dead"       // StateDead indicates that the container failed to be deleted. Containers in this state are attempted to be cleaned up when the daemon restarts.
 )
 
-var validStates = []ContainerState{
-	StateCreated, StateRunning, StatePaused, StateRestarting, StateRemoving, StateExited, StateDead,
+var validStates = []string{
+	string(StateCreated),
+	string(StateRunning),
+	string(StatePaused),
+	string(StateRestarting),
+	string(StateRemoving),
+	string(StateExited),
+	string(StateDead),
 }
 
 // ValidateContainerState checks if the provided string is a valid

api/types/container/state_test.go

@@ -21,7 +21,7 @@ func TestValidateContainerState(t *testing.T) {
 		{state: "invalid-state-string", expectedErr: `invalid value for state (invalid-state-string): must be one of created, running, paused, restarting, removing, exited, dead`},
 	}
 	for _, tc := range tests {
-		t.Run(tc.state, func(t *testing.T) {
+		t.Run(string(tc.state), func(t *testing.T) {
 			err := ValidateContainerState(tc.state)
 			if tc.expectedErr == "" {
 				assert.NilError(t, err)

daemon/container/state.go

@@ -31,7 +31,7 @@ type State struct {
 	//
 	// In a similar fashion, [State.Running] and [State.Restarting] can both
 	// be true in a situation where a container is in process of being restarted.
-	// Refer to [State.StateString] for order of precedence.
+	// Refer to [State.State] for order of precedence.
 	Running           bool
 	Paused            bool
 	Restarting        bool
@@ -114,10 +114,10 @@ func (s *State) String() string {
 	return fmt.Sprintf("Exited (%d) %s ago", s.ExitCode, units.HumanDuration(time.Now().UTC().Sub(s.FinishedAt)))
 }
 
-// StateString returns the container's current [ContainerState], based on the
+// State returns the container's current [container.ContainerState], based on the
 // [State.Running], [State.Paused], [State.Restarting], [State.RemovalInProgress],
 // [State.StartedAt] and [State.Dead] fields.
-func (s *State) StateString() container.ContainerState {
+func (s *State) State() container.ContainerState {
 	if s.Running {
 		if s.Paused {
 			return container.StatePaused
@@ -221,7 +221,7 @@ func (s *State) conditionAlreadyMet(condition container.WaitCondition) bool {
 //
 // In a similar fashion, [State.Running] and [State.Restarting] can both
 // be true in a situation where a container is in process of being restarted.
-// Refer to [State.StateString] for order of precedence.
+// Refer to [State.State] for order of precedence.
 func (s *State) IsRunning() bool {
 	s.Lock()
 	defer s.Unlock()
@@ -327,7 +327,7 @@ func (s *State) SetError(err error) {
 //
 // In a similar fashion, [State.Running] and [State.Restarting] can both
 // be true in a situation where a container is in process of being restarted.
-// Refer to [State.StateString] for order of precedence.
+// Refer to [State.State] for order of precedence.
 func (s *State) IsPaused() bool {
 	s.Lock()
 	defer s.Unlock()
@@ -346,7 +346,7 @@ func (s *State) IsPaused() bool {
 //
 // In a similar fashion, [State.Running] and [State.Restarting] can both
 // be true in a situation where a container is in process of being restarted.
-// Refer to [State.StateString] for order of precedence.
+// Refer to [State.State] for order of precedence.
 func (s *State) IsRestarting() bool {
 	s.Lock()
 	defer s.Unlock()

daemon/container/view.go

@@ -305,7 +305,7 @@ func (v *View) transform(ctr *Container) *Snapshot {
 			ImageID: ctr.ImageID.String(),
 			Ports:   []container.PortSummary{},
 			Mounts:  ctr.GetMountPoints(),
-			State:   ctr.State.StateString(),
+			State:   ctr.State.State(),
 			Status:  ctr.State.String(),
 			Health: &container.HealthSummary{
 				Status:        health,

daemon/container_operations.go

@@ -968,7 +968,7 @@ func (daemon *Daemon) getNetworkedContainer(containerID, connectedContainerPrefi
 		return nil, errdefs.System(errdefs.InvalidParameter(errors.New("cannot join own network namespace")))
 	}
 	if !nc.State.IsRunning() {
-		return nil, errdefs.Conflict(fmt.Errorf("cannot join network namespace of a non running container: container %s is %s", strings.TrimPrefix(nc.Name, "/"), nc.State.StateString()))
+		return nil, errdefs.Conflict(fmt.Errorf("cannot join network namespace of a non running container: container %s is %s", strings.TrimPrefix(nc.Name, "/"), nc.State.State()))
 	}
 	if nc.State.IsRestarting() {
 		return nil, fmt.Errorf("cannot join network namespace of container: %w", errContainerIsRestarting(connectedContainerPrefixOrName))

daemon/delete.go

@@ -92,7 +92,7 @@ func (daemon *Daemon) cleanupContainer(ctr *container.Container, config backend.
 			if ctr.State.Paused {
 				return errdefs.Conflict(errors.New("container is paused and must be unpaused first"))
 			} else {
-				return errdefs.Conflict(fmt.Errorf("container is %s: stop the container before removing or force remove", ctr.State.StateString()))
+				return errdefs.Conflict(fmt.Errorf("container is %s: stop the container before removing or force remove", ctr.State.State()))
 			}
 		}
 		if err := daemon.Kill(ctr); err != nil && !isNotRunning(err) {

daemon/inspect.go

@@ -125,7 +125,7 @@ func (daemon *Daemon) getInspectData(daemonCfg *config.Config, ctr *container.Co
 		Path:    ctr.Path,
 		Args:    ctr.Args,
 		State: &containertypes.State{
-			Status:     ctr.State.StateString(),
+			Status:     ctr.State.State(),
 			Running:    ctr.State.Running,
 			Paused:     ctr.State.Paused,
 			Restarting: ctr.State.Restarting,

daemon/internal/metrics/metrics.go

@@ -91,6 +91,7 @@ func (ctr *StateCounter) Get() (running int, paused int, stopped int) {
 	ctr.mu.RLock()
 	defer ctr.mu.RUnlock()
 
+	// FIXME(thaJeztah): there's no "container.StateStopped"; should we align these states with actual states?
 	for _, state := range ctr.states {
 		switch state {
 		case "running":

daemon/list.go

@@ -281,7 +281,7 @@ func (daemon *Daemon) foldFilter(ctx context.Context, view *container.View, conf
 	}
 
 	err = psFilters.WalkValues("status", func(value string) error {
-		if err := containertypes.ValidateContainerState(value); err != nil {
+		if err := containertypes.ValidateContainerState(containertypes.ContainerState(value)); err != nil {
 			return errdefs.InvalidParameter(fmt.Errorf("invalid filter 'status=%s': %w", value, err))
 		}
 		config.All = true
@@ -486,7 +486,7 @@ func includeContainerInList(container *container.Snapshot, filter *listContext)
 	}
 
 	// Do not include container if its status doesn't match the filter
-	if !filter.filters.Match("status", container.State) {
+	if !filter.filters.Match("status", string(container.State)) {
 		return excludeContainer
 	}
 

daemon/monitor.go

@@ -8,6 +8,7 @@ import (
 
 	cerrdefs "github.com/containerd/errdefs"
 	"github.com/containerd/log"
+	containertypes "github.com/moby/moby/api/types/container"
 	"github.com/moby/moby/api/types/events"
 	"github.com/moby/moby/v2/daemon/config"
 	"github.com/moby/moby/v2/daemon/container"
@@ -19,10 +20,10 @@ import (
 )
 
 func (daemon *Daemon) setStateCounter(c *container.Container) {
-	switch c.State.StateString() {
-	case "paused":
+	switch c.State.State() {
+	case containertypes.StatePaused:
 		metrics.StateCtr.Set(c.ID, "paused")
-	case "running":
+	case containertypes.StateRunning:
 		metrics.StateCtr.Set(c.ID, "running")
 	default:
 		metrics.StateCtr.Set(c.ID, "stopped")

integration/container/kill_test.go

@@ -92,17 +92,17 @@ func TestKillWithStopSignalAndRestartPolicies(t *testing.T) {
 	testCases := []struct {
 		doc        string
 		stopsignal string
-		status     string
+		status     containertypes.ContainerState
 	}{
 		{
 			doc:        "same-signal-disables-restart-policy",
 			stopsignal: "TERM",
-			status:     "exited",
+			status:     containertypes.StateExited,
 		},
 		{
 			doc:        "different-signal-keep-restart-policy",
 			stopsignal: "CONT",
-			status:     "running",
+			status:     containertypes.StateRunning,
 		},
 	}
 

integration/internal/container/states.go

@@ -39,15 +39,17 @@ func IsInState(ctx context.Context, apiClient client.APIClient, containerID stri
 		if err != nil {
 			return poll.Error(err)
 		}
+		var states []string
 		for _, v := range state {
+			states = append(states, string(v))
 			if inspect.Container.State.Status == v {
 				return poll.Success()
 			}
 		}
-		if len(state) == 1 {
+		if len(states) == 1 {
 			return poll.Continue("waiting for container State.Status to be '%s', currently '%s'", state[0], inspect.Container.State.Status)
 		} else {
-			return poll.Continue("waiting for container State.Status to be one of (%s), currently '%s'", strings.Join(state, ", "), inspect.Container.State.Status)
+			return poll.Continue("waiting for container State.Status to be one of (%s), currently '%s'", strings.Join(states, ", "), inspect.Container.State.Status)
 		}
 	}
 }

vendor/github.com/moby/moby/api/types/container/state.go

@@ -6,9 +6,7 @@ import (
 )
 
 // ContainerState is a string representation of the container's current state.
-//
-// It currently is an alias for string, but may become a distinct type in the future.
-type ContainerState = string
+type ContainerState string
 
 const (
 	StateCreated    ContainerState = "created"    // StateCreated indicates the container is created, but not (yet) started.
@@ -20,8 +18,14 @@ const (
 	StateDead       ContainerState = "dead"       // StateDead indicates that the container failed to be deleted. Containers in this state are attempted to be cleaned up when the daemon restarts.
 )
 
-var validStates = []ContainerState{
-	StateCreated, StateRunning, StatePaused, StateRestarting, StateRemoving, StateExited, StateDead,
+var validStates = []string{
+	string(StateCreated),
+	string(StateRunning),
+	string(StatePaused),
+	string(StateRestarting),
+	string(StateRemoving),
+	string(StateExited),
+	string(StateDead),
 }
 
 // ValidateContainerState checks if the provided string is a valid