Support State.Error field in inspect command

cmd/nerdctl/container_create.go

@@ -51,7 +51,7 @@ func newCreateCommand() *cobra.Command {
 	return createCommand
 }
 
-func createAction(cmd *cobra.Command, args []string) error {
+func createAction(cmd *cobra.Command, args []string) (err error) {
 	globalOptions, err := processRootCmdFlags(cmd)
 	if err != nil {
 		return err
@@ -91,6 +91,13 @@ func createAction(cmd *cobra.Command, args []string) error {
 		}
 		return err
 	}
+	// defer setting `nerdctl/error` label in case of error
+	defer func() {
+		if err != nil {
+			containerutil.UpdateErrorLabel(ctx, container, err)
+		}
+	}()
+
 	fmt.Fprintln(cmd.OutOrStdout(), container.ID())
 	return nil
 }

cmd/nerdctl/container_inspect_linux_test.go

@@ -18,6 +18,7 @@ package main
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/containerd/nerdctl/pkg/inspecttypes/dockercompat"
@@ -154,3 +155,56 @@ func TestContainerInspectContainsLabel(t *testing.T) {
 	assert.Equal(base.T, "foo", lbs["foo"])
 	assert.Equal(base.T, "bar", lbs["bar"])
 }
+
+func TestContainerInspectState(t *testing.T) {
+	t.Parallel()
+	testContainer := testutil.Identifier(t)
+	base := testutil.NewBase(t)
+
+	type testCase struct {
+		name, containerName, cmd string
+		want                     dockercompat.ContainerState
+	}
+	// nerdctl: run error produces a nil Task, so the Status is empty because Status comes from Task.
+	// docker : run error gives => `Status=created` as  in docker there is no a separation between container and Task.
+	errStatus := ""
+	if base.Target == testutil.Docker {
+		errStatus = "created"
+	}
+	testCases := []testCase{
+		{
+			name:          "inspect State with error",
+			containerName: fmt.Sprintf("%s-fail", testContainer),
+			cmd:           "aa",
+			want: dockercompat.ContainerState{
+				Error:  "executable file not found in $PATH",
+				Status: errStatus,
+			},
+		},
+		{
+			name:          "inspect State without error",
+			containerName: fmt.Sprintf("%s-success", testContainer),
+			cmd:           "ls",
+			want: dockercompat.ContainerState{
+				Error:  "",
+				Status: "exited",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			defer base.Cmd("rm", "-f", tc.containerName).Run()
+			if tc.want.Error != "" {
+				base.Cmd("run", "--name", tc.containerName, testutil.AlpineImage, tc.cmd).AssertFail()
+			} else {
+				base.Cmd("run", "--name", tc.containerName, testutil.AlpineImage, tc.cmd).AssertOK()
+			}
+			inspect := base.InspectContainer(tc.containerName)
+			assert.Assert(t, strings.Contains(inspect.State.Error, tc.want.Error), fmt.Sprintf("expected: %s, actual: %s", tc.want.Error, inspect.State.Error))
+			assert.Equal(base.T, inspect.State.Status, tc.want.Status)
+		})
+	}
+
+}

cmd/nerdctl/container_run.go

@@ -293,7 +293,7 @@ func setCreateFlags(cmd *cobra.Command) {
 
 // runAction is heavily based on ctr implementation:
 // https://github.com/containerd/containerd/blob/v1.4.3/cmd/ctr/commands/run/run.go
-func runAction(cmd *cobra.Command, args []string) error {
+func runAction(cmd *cobra.Command, args []string) (err error) {
 	globalOptions, err := processRootCmdFlags(cmd)
 	if err != nil {
 		return err
@@ -346,6 +346,12 @@ func runAction(cmd *cobra.Command, args []string) error {
 		}
 		return err
 	}
+	// defer setting `nerdctl/error` label in case of error
+	defer func() {
+		if err != nil {
+			containerutil.UpdateErrorLabel(ctx, c, err)
+		}
+	}()
 
 	id := c.ID()
 	if rm && !flagD {

pkg/cmd/container/remove.go

@@ -90,6 +90,12 @@ func Remove(ctx context.Context, client *containerd.Client, containers []string,
 
 // RemoveContainer removes a container from containerd store.
 func RemoveContainer(ctx context.Context, c containerd.Container, globalOptions types.GlobalCommandOptions, force bool, removeAnonVolumes bool) (retErr error) {
+	// defer the storage of remove error in the dedicated label
+	defer func() {
+		if retErr != nil {
+			containerutil.UpdateErrorLabel(ctx, c, retErr)
+		}
+	}()
 	ns, err := namespaces.NamespaceRequired(ctx)
 	if err != nil {
 		return err

pkg/containerutil/containerutil.go

@@ -114,6 +114,15 @@ func UpdateExplicitlyStoppedLabel(ctx context.Context, container containerd.Cont
 	return container.Update(ctx, containerd.UpdateContainerOpts(opt))
 }
 
+// UpdateErrorLabel updates the "nerdctl/error"
+// label of the container according to the container error.
+func UpdateErrorLabel(ctx context.Context, container containerd.Container, err error) error {
+	opt := containerd.WithAdditionalContainerLabels(map[string]string{
+		labels.Error: err.Error(),
+	})
+	return container.Update(ctx, containerd.UpdateContainerOpts(opt))
+}
+
 // WithBindMountHostProcfs replaces procfs mount with rbind.
 // Required for --pid=host on rootless.
 //
@@ -189,7 +198,13 @@ func GenerateSharingPIDOpts(ctx context.Context, targetCon containerd.Container)
 }
 
 // Start starts `container` with `attach` flag. If `attach` is true, it will attach to the container's stdio.
-func Start(ctx context.Context, container containerd.Container, flagA bool, client *containerd.Client) error {
+func Start(ctx context.Context, container containerd.Container, flagA bool, client *containerd.Client) (err error) {
+	// defer the storage of start error in the dedicated label
+	defer func() {
+		if err != nil {
+			UpdateErrorLabel(ctx, container, err)
+		}
+	}()
 	lab, err := container.Labels(ctx)
 	if err != nil {
 		return err
@@ -272,7 +287,13 @@ func Start(ctx context.Context, container containerd.Container, flagA bool, clie
 }
 
 // Stop stops `container` by sending SIGTERM. If the container is not stopped after `timeout`, it sends a SIGKILL.
-func Stop(ctx context.Context, container containerd.Container, timeout *time.Duration) error {
+func Stop(ctx context.Context, container containerd.Container, timeout *time.Duration) (err error) {
+	// defer the storage of stop error in the dedicated label
+	defer func() {
+		if err != nil {
+			UpdateErrorLabel(ctx, container, err)
+		}
+	}()
 	if err := UpdateExplicitlyStoppedLabel(ctx, container, true); err != nil {
 		return err
 	}

pkg/errutil/exit_coder.go

@@ -25,7 +25,6 @@ type ExitCoder interface {
 
 // ExitCodeError is to allow the program to exit with status code without outputting an error message.
 type ExitCodeError struct {
-	error
 	exitCode int
 }
 
@@ -39,6 +38,10 @@ func (e ExitCodeError) ExitCode() int {
 	return e.exitCode
 }
 
+func (e ExitCodeError) Error() string {
+	return ""
+}
+
 func HandleExitCoder(err error) {
 	if err == nil {
 		return

pkg/inspecttypes/dockercompat/dockercompat.go

@@ -167,7 +167,7 @@ type ContainerState struct {
 	// TODO:	Dead       bool
 	Pid      int
 	ExitCode int
-	// TODO: Error      string
+	Error    string
 	// TODO: StartedAt  string
 	FinishedAt string
 	// TODO: Health     *Health `json:",omitempty"`
@@ -257,23 +257,23 @@ func ContainerFromNative(n *native.Container) (*Container, error) {
 		c.Mounts = mounts
 	}
 
+	cs := new(ContainerState)
+	cs.Restarting = n.Labels[restart.StatusLabel] == string(containerd.Running)
+	cs.Error = n.Labels[labels.Error]
 	if n.Process != nil {
-		c.State = &ContainerState{
-			Status:     statusFromNative(n.Process.Status, n.Labels),
-			Running:    n.Process.Status.Status == containerd.Running,
-			Paused:     n.Process.Status.Status == containerd.Paused,
-			Restarting: n.Labels[restart.StatusLabel] == string(containerd.Running),
-			Pid:        n.Process.Pid,
-			ExitCode:   int(n.Process.Status.ExitStatus),
-			FinishedAt: n.Process.Status.ExitTime.Format(time.RFC3339Nano),
-		}
+		cs.Status = statusFromNative(n.Process.Status, n.Labels)
+		cs.Running = n.Process.Status.Status == containerd.Running
+		cs.Paused = n.Process.Status.Status == containerd.Paused
+		cs.Pid = n.Process.Pid
+		cs.ExitCode = int(n.Process.Status.ExitStatus)
+		cs.FinishedAt = n.Process.Status.ExitTime.Format(time.RFC3339Nano)
 		nSettings, err := networkSettingsFromNative(n.Process.NetNS, n.Spec.(*specs.Spec))
 		if err != nil {
 			return nil, err
 		}
 		c.NetworkSettings = nSettings
 	}
-
+	c.State = cs
 	c.Config = &Config{
 		Hostname: n.Labels[labels.Hostname],
 		Labels:   n.Labels,

pkg/labels/labels.go

@@ -58,7 +58,6 @@ const (
 	Ports = Prefix + "ports"
 
 	// IPAddress is the static IP address of the container assigned by the user
-
 	IPAddress = Prefix + "ip"
 
 	// LogURI is the log URI
@@ -90,6 +89,10 @@ const (
 	// PIDContainer is the `nerdctl run --pid` for restarting
 	PIDContainer = Prefix + "pid-container"
 
+	// Error encapsulates a container human-readable string
+	// that describes container error.
+	Error = Prefix + "error"
+
 	// NerdctlDefaultNetwork indicates whether a network is the default network
 	// created and owned by Nerdctl.
 	// Boolean value which can be parsed with strconv.ParseBool() is required.