remove undocumented top-level "docker remove" command

This was introduced in 9b54d86,
which added `docker container remove` as alias for `docker container rm`.

However, due to the `NewRmCommand` being used both for adding the top-level
`docker rm` command and for adding the `docker container rm` command, it
also introduced a (hidden) top-level `docker remove` command;

    docker remove --help | head -n1
    Usage:  docker rm [OPTIONS] CONTAINER [CONTAINER...]

The command was not documented, and did not appear in `--help` output,
nor was auto-complete provided;

    docker --help | grep remove

    docker r<TAB>
    rename               (Rename a container)  rm  (Remove one or more containers)  run  (Create and run a new container from an image)
    restart  (Restart one or more containers)  rmi     (Remove one or more images)

This patch adds a dedicated, non-exported `newRemoveCommand` to add sub-
commands for `docker container`, taking a similar approach as was done in
[moby@b993609d5a] for `docker image rm`.

With this patch applied, the hidden command is no longer there, but
the `docker rm`, `docker container rm`, and `docker container remove`
commands stay functional as intended;

    docker remove foo
    docker: unknown command: docker remove

    Run 'docker --help' for more information

    docker rm --help | head -n1
    Usage:  docker rm [OPTIONS] CONTAINER [CONTAINER...]
    docker container rm --help | head -n1
    Usage:  docker container rm [OPTIONS] CONTAINER [CONTAINER...]
    docker container remove --help | head -n1
    Usage:  docker container rm [OPTIONS] CONTAINER [CONTAINER...]

[moby@b993609d5a]: moby/moby@b993609

Reported-by: Lorenzo Buero <[email protected]>
Co-authored-by: Lorenzo Buero <[email protected]>
Signed-off-by: Sebastiaan van Stijn <[email protected]>

Author: thaJeztah

cli/command/container/cmd.go

@@ -28,7 +28,7 @@ func NewContainerCommand(dockerCli command.Cli) *cobra.Command {
 		NewPortCommand(dockerCli),
 		NewRenameCommand(dockerCli),
 		NewRestartCommand(dockerCli),
-		NewRmCommand(dockerCli),
+		newRemoveCommand(dockerCli),
 		NewRunCommand(dockerCli),
 		NewStartCommand(dockerCli),
 		NewStatsCommand(dockerCli),

cli/command/container/rm.go

@@ -27,10 +27,9 @@ func NewRmCommand(dockerCli command.Cli) *cobra.Command {
 	var opts rmOptions
 
 	cmd := &cobra.Command{
-		Use:     "rm [OPTIONS] CONTAINER [CONTAINER...]",
-		Aliases: []string{"remove"},
-		Short:   "Remove one or more containers",
-		Args:    cli.RequiresMinArgs(1),
+		Use:   "rm [OPTIONS] CONTAINER [CONTAINER...]",
+		Short: "Remove one or more containers",
+		Args:  cli.RequiresMinArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			opts.containers = args
 			return runRm(cmd.Context(), dockerCli, &opts)
@@ -50,6 +49,15 @@ func NewRmCommand(dockerCli command.Cli) *cobra.Command {
 	return cmd
 }
 
+// newRemoveCommand adds subcommands for "docker container"; unlike the
+// top-level "docker rm", it also adds a "remove" alias to support
+// "docker container remove" in addition to "docker container rm".
+func newRemoveCommand(dockerCli command.Cli) *cobra.Command {
+	cmd := *NewRmCommand(dockerCli)
+	cmd.Aliases = []string{"rm", "remove"}
+	return &cmd
+}
+
 func runRm(ctx context.Context, dockerCLI command.Cli, opts *rmOptions) error {
 	apiClient := dockerCLI.Client()
 	errChan := parallelOperation(ctx, opts.containers, func(ctx context.Context, ctrID string) error {