feat: support for -a and --attach in run

Signed-off-by: CodeChanning <[email protected]>

cmd/nerdctl/container_run.go

@@ -69,6 +69,7 @@ func newRunCommand() *cobra.Command {
  setCreateFlags(runCommand)
 
  runCommand.Flags().BoolP("detach", "d", false, "Run container in background and print container ID")
+ runCommand.Flags().StringSliceP("attach", "a", []string{}, "Attach STDIN, STDOUT, or STDERR")
 
  return runCommand
 }
@@ -304,6 +305,10 @@ func processCreateCommandFlagsInRun(cmd *cobra.Command) (opt types.ContainerCrea
  if err != nil {
  return
  }
+ opt.Attach, err = cmd.Flags().GetStringSlice("attach")
+ if err != nil {
+ return
+ }
  return opt, nil
 }
 
@@ -325,6 +330,10 @@ func runAction(cmd *cobra.Command, args []string) error {
  return errors.New("flags -d and --rm cannot be specified together")
  }
 
+ if len(createOpt.Attach) > 0 && createOpt.Detach {
+ return errors.New("flags -d and -a cannot be specified together")
+ }
+
  netFlags, err := loadNetworkFlags(cmd)
  if err != nil {
  return fmt.Errorf("failed to load networking flags: %s", err)
@@ -381,7 +390,7 @@ func runAction(cmd *cobra.Command, args []string) error {
  }
  logURI := lab[labels.LogURI]
  detachC := make(chan struct{})
- task, err := taskutil.NewTask(ctx, client, c, false, createOpt.Interactive, createOpt.TTY, createOpt.Detach,
+ task, err := taskutil.NewTask(ctx, client, c, createOpt.Attach, createOpt.Interactive, createOpt.TTY, createOpt.Detach,
  con, logURI, createOpt.DetachKeys, createOpt.GOptions.Namespace, detachC)
  if err != nil {
  return err

cmd/nerdctl/container_run_test.go

@@ -533,3 +533,39 @@ func TestRunRmTime(t *testing.T) {
  t.Fatalf("expected to have completed in %v, took %v", deadline, took)
  }
 }
+
+func TestRunAttachStdin(t *testing.T) {
+ if runtime.GOOS == "windows" {
+ t.Skip("run attach test is not yet implemented on Windows")
+ }
+
+ t.Parallel()
+ base := testutil.NewBase(t)
+ containerName := testutil.Identifier(t)
+
+ const testStr = "test-run-stdio"
+ opts := []func(*testutil.Cmd){
+ testutil.WithStdin(strings.NewReader("echo " + testStr + "\nexit\n")),
+ }
+
+ args := []string{"run", "--rm", "-i", "-a", "stdin", "-a", "stdout", "--name", containerName, testutil.CommonImage}
+ if testutil.GetTarget() == testutil.Docker {
+ args = append(args, "cat")
+ }
+
+ defer base.Cmd("rm", "-f", containerName).AssertOK()
+ base.Cmd(args...).CmdOption(opts...).AssertOutContains(testStr)
+}
+
+func TestRunAttachStdout(t *testing.T) {
+ if runtime.GOOS == "windows" {
+ t.Skip("run attach test is not yet implemented on Windows")
+ }
+
+ t.Parallel()
+ base := testutil.NewBase(t)
+ containerName := testutil.Identifier(t)
+
+ defer base.Cmd("rm", "-f", containerName).AssertOK()
+ base.Cmd("run", "-a", "stdout", "--name", containerName, testutil.CommonImage, "sh", "-euxc", "echo foo").AssertOutContains("foo")
+}

docs/command-reference.md

@@ -137,6 +137,7 @@ Usage: `nerdctl run [OPTIONS] IMAGE [COMMAND] [ARG...]`
 
 Basic flags:
 
+- :whale: `-a, --attach`: Attach STDIN, STDOUT, or STDERR
 - :whale: :blue_square: `-i, --interactive`: Keep STDIN open even if not attached"
 - :whale: :blue_square: `-t, --tty`: Allocate a pseudo-TTY
  - :warning: WIP: currently `-t` conflicts with `-d`
@@ -387,7 +388,7 @@ IPFS flags:
 - :nerd_face: `--ipfs-address`: Multiaddr of IPFS API (default uses `$IPFS_PATH` env variable if defined or local directory `~/.ipfs`)
 
 Unimplemented `docker run` flags:
- `--attach`, `--blkio-weight-device`, `--cpu-rt-*`, `--device-*`,
+ `--blkio-weight-device`, `--cpu-rt-*`, `--device-*`,
  `--disable-content-trust`, `--domainname`, `--expose`, `--health-*`, `--isolation`, `--no-healthcheck`,
  `--link*`, `--publish-all`, `--storage-opt`,
  `--userns`, `--volume-driver`

pkg/api/types/container_types.go

@@ -68,6 +68,8 @@ type ContainerCreateOptions struct {
  Detach bool
  // The key sequence for detaching a container.
  DetachKeys string
+ // Attach STDIN, STDOUT, or STDERR
+ Attach []string
  // Restart specifies the policy to apply when a container exits
  Restart string
  // Rm specifies whether to remove the container automatically when it exits

pkg/containerutil/containerutil.go

@@ -272,7 +272,11 @@ func Start(ctx context.Context, container containerd.Container, flagA bool, clie
  }
  }
  detachC := make(chan struct{})
- task, err := taskutil.NewTask(ctx, client, container, flagA, false, flagT, true, con, logURI, detachKeys, namespace, detachC)
+ flagAStreams := []string{}
+ if flagA {
+ flagAStreams = []string{"STDOUT", "STDERR"}
+ }
+ task, err := taskutil.NewTask(ctx, client, container, flagAStreams, false, flagT, true, con, logURI, detachKeys, namespace, detachC)
  if err != nil {
  return err
  }

pkg/taskutil/taskutil.go

@@ -23,6 +23,8 @@ import (
  "net/url"
  "os"
  "runtime"
+ "slices"
+ "strings"
  "sync"
  "syscall"
 
@@ -37,9 +39,9 @@ import (
  "golang.org/x/term"
 )
 
-// NewTask is from https://github.com/containerd/containerd/blob/v1.4.3/cmd/ctr/commands/tasks/tasks_unix.go#L70-L108
 func NewTask(ctx context.Context, client *containerd.Client, container containerd.Container,
- flagA, flagI, flagT, flagD bool, con console.Console, logURI, detachKeys, namespace string, detachC chan<- struct{}) (containerd.Task, error) {
+ flagA []string, flagI, flagT, flagD bool, con console.Console, logURI, detachKeys, namespace string, detachC chan<- struct{}) (containerd.Task, error) {
+
  var t containerd.Task
  closer := func() {
  if detachC != nil {
@@ -59,7 +61,7 @@ func NewTask(ctx context.Context, client *containerd.Client, container container
  io.Cancel()
  }
  var ioCreator cio.Creator
- if flagA {
+ if len(flagA) != 0 {
  log.G(ctx).Debug("attaching output instead of using the log-uri")
  if flagT {
  in, err := consoleutil.NewDetachableStdin(con, detachKeys, closer)
@@ -68,7 +70,8 @@ func NewTask(ctx context.Context, client *containerd.Client, container container
  }
  ioCreator = cio.NewCreator(cio.WithStreams(in, con, nil), cio.WithTerminal)
  } else {
- ioCreator = cio.NewCreator(cio.WithStdio)
+ streams := flagAStreams(flagA)
+ ioCreator = cio.NewCreator(cio.WithStreams(streams.stdIn, streams.stdOut, streams.stdErr))
  }
 
  } else if flagT && flagD {
@@ -146,6 +149,51 @@ func NewTask(ctx context.Context, client *containerd.Client, container container
  return t, nil
 }
 
+// struct used to store streams specified with flagA (-a, --attach)
+type streams struct {
+ stdIn *os.File
+ stdOut *os.File
+ stdErr *os.File
+}
+
+func nullStream() *os.File {
+ devNull, err := os.Open("/dev/null")
+ if err != nil {
+ return nil
+ }
+ defer devNull.Close()
+
+ return devNull
+}
+
+func flagAStreams(streamsArr []string) streams {
+ stdIn := os.Stdin
+ stdOut := os.Stdout
+ stdErr := os.Stderr
+
+ for i, str := range streamsArr {
+ streamsArr[i] = strings.ToUpper(str)
+ }
+
+ if !slices.Contains(streamsArr, "STDIN") {
+ stdIn = nullStream()
+ }
+
+ if !slices.Contains(streamsArr, "STDOUT") {
+ stdOut = nullStream()
+ }
+
+ if !slices.Contains(streamsArr, "STDERR") {
+ stdErr = nullStream()
+ }
+
+ return streams{
+ stdIn: stdIn,
+ stdOut: stdOut,
+ stdErr: stdErr,
+ }
+}
+
 // StdinCloser is from https://github.com/containerd/containerd/blob/v1.4.3/cmd/ctr/commands/tasks/exec.go#L181-L194
 type StdinCloser struct {
  mu sync.Mutex