package main import ( "errors" "fmt" "os" "strings" "github.com/docker/cli/cli" pluginmanager "github.com/docker/cli/cli-plugins/manager" "github.com/docker/cli/cli/command" "github.com/docker/cli/cli/command/commands" cliflags "github.com/docker/cli/cli/flags" "github.com/docker/cli/cli/version" "github.com/docker/docker/api/types/versions" "github.com/docker/docker/client" "github.com/sirupsen/logrus" "github.com/spf13/cobra" "github.com/spf13/pflag" ) func newDockerCommand(dockerCli *command.DockerCli) *cobra.Command { var ( opts *cliflags.ClientOptions flags *pflag.FlagSet helpCmd *cobra.Command ) cmd := &cobra.Command{ Use: "docker [OPTIONS] COMMAND [ARG...]", Short: "A self-sufficient runtime for containers", SilenceUsage: true, SilenceErrors: true, TraverseChildren: true, FParseErrWhitelist: cobra.FParseErrWhitelist{ // UnknownFlags ignores any unknown // --arguments on the top-level docker command // only. This is necessary to allow passing // --arguments to plugins otherwise // e.g. `docker plugin --foo` is caught here // in the monolithic CLI and `foo` is reported // as an unknown argument. UnknownFlags: true, }, RunE: func(cmd *cobra.Command, args []string) error { if len(args) == 0 { return command.ShowHelp(dockerCli.Err())(cmd, args) } plugincmd, err := pluginmanager.PluginRunCommand(dockerCli, args[0], cmd) if pluginmanager.IsNotFound(err) { return fmt.Errorf( "docker: '%s' is not a docker command.\nSee 'docker --help'", args[0]) } if err != nil { return err } return plugincmd.Run() }, PersistentPreRunE: func(cmd *cobra.Command, args []string) error { // flags must be the top-level command flags, not cmd.Flags() opts.Common.SetDefaultOptions(flags) if err := dockerCli.Initialize(opts); err != nil { return err } return isSupported(cmd, dockerCli) }, Version: fmt.Sprintf("%s, build %s", version.Version, version.GitCommit), DisableFlagsInUseLine: true, } opts, flags, helpCmd = cli.SetupRootCommand(cmd) flags.BoolP("version", "v", false, "Print version information and quit") setFlagErrorFunc(dockerCli, cmd, flags, opts) setupHelpCommand(dockerCli, cmd, helpCmd, flags, opts) setHelpFunc(dockerCli, cmd, flags, opts) cmd.SetOutput(dockerCli.Out()) commands.AddCommands(cmd, dockerCli) cli.DisableFlagsInUseLine(cmd) setValidateArgs(dockerCli, cmd, flags, opts) return cmd } func setFlagErrorFunc(dockerCli *command.DockerCli, cmd *cobra.Command, flags *pflag.FlagSet, opts *cliflags.ClientOptions) { // When invoking `docker stack --nonsense`, we need to make sure FlagErrorFunc return appropriate // output if the feature is not supported. // As above cli.SetupRootCommand(cmd) have already setup the FlagErrorFunc, we will add a pre-check before the FlagErrorFunc // is called. flagErrorFunc := cmd.FlagErrorFunc() cmd.SetFlagErrorFunc(func(cmd *cobra.Command, err error) error { if err := initializeDockerCli(dockerCli, flags, opts); err != nil { return err } if err := isSupported(cmd, dockerCli); err != nil { return err } return flagErrorFunc(cmd, err) }) } func setupHelpCommand(dockerCli *command.DockerCli, rootCmd, helpCmd *cobra.Command, flags *pflag.FlagSet, opts *cliflags.ClientOptions) { origRun := helpCmd.Run origRunE := helpCmd.RunE helpCmd.Run = nil helpCmd.RunE = func(c *cobra.Command, args []string) error { // No Persistent* hooks are called for help, so we must initialize here. if err := initializeDockerCli(dockerCli, flags, opts); err != nil { return err } if len(args) > 0 { helpcmd, err := pluginmanager.PluginRunCommand(dockerCli, args[0], rootCmd) if err == nil { err = helpcmd.Run() if err != nil { return err } } if !pluginmanager.IsNotFound(err) { return err } } if origRunE != nil { return origRunE(c, args) } origRun(c, args) return nil } } func tryRunPluginHelp(dockerCli command.Cli, ccmd *cobra.Command, cargs []string) error { root := ccmd.Root() cmd, _, err := root.Traverse(cargs) if err != nil { return err } helpcmd, err := pluginmanager.PluginRunCommand(dockerCli, cmd.Name(), root) if err != nil { return err } return helpcmd.Run() } func setHelpFunc(dockerCli *command.DockerCli, cmd *cobra.Command, flags *pflag.FlagSet, opts *cliflags.ClientOptions) { defaultHelpFunc := cmd.HelpFunc() cmd.SetHelpFunc(func(ccmd *cobra.Command, args []string) { if err := initializeDockerCli(dockerCli, flags, opts); err != nil { ccmd.Println(err) return } // Add a stub entry for every plugin so they are // included in the help output and so that // `tryRunPluginHelp` can find them or if we fall // through they will be included in the default help // output. if err := pluginmanager.AddPluginCommandStubs(dockerCli, ccmd.Root()); err != nil { ccmd.Println(err) return } if len(args) >= 1 { err := tryRunPluginHelp(dockerCli, ccmd, args) if err == nil { // Successfully ran the plugin return } if !pluginmanager.IsNotFound(err) { ccmd.Println(err) return } } if err := isSupported(ccmd, dockerCli); err != nil { ccmd.Println(err) return } if err := hideUnsupportedFeatures(ccmd, dockerCli); err != nil { ccmd.Println(err) return } defaultHelpFunc(ccmd, args) }) } func setValidateArgs(dockerCli *command.DockerCli, cmd *cobra.Command, flags *pflag.FlagSet, opts *cliflags.ClientOptions) { // The Args is handled by ValidateArgs in cobra, which does not allows a pre-hook. // As a result, here we replace the existing Args validation func to a wrapper, // where the wrapper will check to see if the feature is supported or not. // The Args validation error will only be returned if the feature is supported. cli.VisitAll(cmd, func(ccmd *cobra.Command) { // if there is no tags for a command or any of its parent, // there is no need to wrap the Args validation. if !hasTags(ccmd) { return } if ccmd.Args == nil { return } cmdArgs := ccmd.Args ccmd.Args = func(cmd *cobra.Command, args []string) error { if err := initializeDockerCli(dockerCli, flags, opts); err != nil { return err } if err := isSupported(cmd, dockerCli); err != nil { return err } return cmdArgs(cmd, args) } }) } func initializeDockerCli(dockerCli *command.DockerCli, flags *pflag.FlagSet, opts *cliflags.ClientOptions) error { if dockerCli.Client() != nil { return nil } // when using --help, PersistentPreRun is not called, so initialization is needed. // flags must be the top-level command flags, not cmd.Flags() opts.Common.SetDefaultOptions(flags) return dockerCli.Initialize(opts) } func main() { dockerCli, err := command.NewDockerCli() if err != nil { fmt.Fprintln(os.Stderr, err) os.Exit(1) } logrus.SetOutput(dockerCli.Err()) cmd := newDockerCommand(dockerCli) if err := cmd.Execute(); err != nil { if sterr, ok := err.(cli.StatusError); ok { if sterr.Status != "" { fmt.Fprintln(dockerCli.Err(), sterr.Status) } // StatusError should only be used for errors, and all errors should // have a non-zero exit status, so never exit with 0 if sterr.StatusCode == 0 { os.Exit(1) } os.Exit(sterr.StatusCode) } fmt.Fprintln(dockerCli.Err(), err) os.Exit(1) } } type versionDetails interface { Client() client.APIClient ClientInfo() command.ClientInfo ServerInfo() command.ServerInfo } func hideFeatureFlag(f *pflag.Flag, hasFeature bool, annotation string) { if hasFeature { return } if _, ok := f.Annotations[annotation]; ok { f.Hidden = true } } func hideFeatureSubCommand(subcmd *cobra.Command, hasFeature bool, annotation string) { if hasFeature { return } if _, ok := subcmd.Annotations[annotation]; ok { subcmd.Hidden = true } } func hideUnsupportedFeatures(cmd *cobra.Command, details versionDetails) error { clientVersion := details.Client().ClientVersion() osType := details.ServerInfo().OSType hasExperimental := details.ServerInfo().HasExperimental hasExperimentalCLI := details.ClientInfo().HasExperimental hasBuildKit, err := command.BuildKitEnabled(details.ServerInfo()) if err != nil { return err } cmd.Flags().VisitAll(func(f *pflag.Flag) { hideFeatureFlag(f, hasExperimental, "experimental") hideFeatureFlag(f, hasExperimentalCLI, "experimentalCLI") hideFeatureFlag(f, hasBuildKit, "buildkit") hideFeatureFlag(f, !hasBuildKit, "no-buildkit") // hide flags not supported by the server if !isOSTypeSupported(f, osType) || !isVersionSupported(f, clientVersion) { f.Hidden = true } // root command shows all top-level flags if cmd.Parent() != nil { if commands, ok := f.Annotations["top-level"]; ok { f.Hidden = !findCommand(cmd, commands) } } }) for _, subcmd := range cmd.Commands() { hideFeatureSubCommand(subcmd, hasExperimental, "experimental") hideFeatureSubCommand(subcmd, hasExperimentalCLI, "experimentalCLI") hideFeatureSubCommand(subcmd, hasBuildKit, "buildkit") hideFeatureSubCommand(subcmd, !hasBuildKit, "no-buildkit") // hide subcommands not supported by the server if subcmdVersion, ok := subcmd.Annotations["version"]; ok && versions.LessThan(clientVersion, subcmdVersion) { subcmd.Hidden = true } if v, ok := subcmd.Annotations["ostype"]; ok && v != osType { subcmd.Hidden = true } } return nil } // Checks if a command or one of its ancestors is in the list func findCommand(cmd *cobra.Command, commands []string) bool { if cmd == nil { return false } for _, c := range commands { if c == cmd.Name() { return true } } return findCommand(cmd.Parent(), commands) } func isSupported(cmd *cobra.Command, details versionDetails) error { if err := areSubcommandsSupported(cmd, details); err != nil { return err } return areFlagsSupported(cmd, details) } func areFlagsSupported(cmd *cobra.Command, details versionDetails) error { clientVersion := details.Client().ClientVersion() osType := details.ServerInfo().OSType hasExperimental := details.ServerInfo().HasExperimental hasExperimentalCLI := details.ClientInfo().HasExperimental errs := []string{} cmd.Flags().VisitAll(func(f *pflag.Flag) { if f.Changed { if !isVersionSupported(f, clientVersion) { errs = append(errs, fmt.Sprintf("\"--%s\" requires API version %s, but the Docker daemon API version is %s", f.Name, getFlagAnnotation(f, "version"), clientVersion)) return } if !isOSTypeSupported(f, osType) { errs = append(errs, fmt.Sprintf("\"--%s\" is only supported on a Docker daemon running on %s, but the Docker daemon is running on %s", f.Name, getFlagAnnotation(f, "ostype"), osType)) return } if _, ok := f.Annotations["experimental"]; ok && !hasExperimental { errs = append(errs, fmt.Sprintf("\"--%s\" is only supported on a Docker daemon with experimental features enabled", f.Name)) } if _, ok := f.Annotations["experimentalCLI"]; ok && !hasExperimentalCLI { errs = append(errs, fmt.Sprintf("\"--%s\" is on a Docker cli with experimental cli features enabled", f.Name)) } // buildkit-specific flags are noop when buildkit is not enabled, so we do not add an error in that case } }) if len(errs) > 0 { return errors.New(strings.Join(errs, "\n")) } return nil } // Check recursively so that, e.g., `docker stack ls` returns the same output as `docker stack` func areSubcommandsSupported(cmd *cobra.Command, details versionDetails) error { clientVersion := details.Client().ClientVersion() osType := details.ServerInfo().OSType hasExperimental := details.ServerInfo().HasExperimental hasExperimentalCLI := details.ClientInfo().HasExperimental // Check recursively so that, e.g., `docker stack ls` returns the same output as `docker stack` for curr := cmd; curr != nil; curr = curr.Parent() { if cmdVersion, ok := curr.Annotations["version"]; ok && versions.LessThan(clientVersion, cmdVersion) { return fmt.Errorf("%s requires API version %s, but the Docker daemon API version is %s", cmd.CommandPath(), cmdVersion, clientVersion) } if os, ok := curr.Annotations["ostype"]; ok && os != osType { return fmt.Errorf("%s is only supported on a Docker daemon running on %s, but the Docker daemon is running on %s", cmd.CommandPath(), os, osType) } if _, ok := curr.Annotations["experimental"]; ok && !hasExperimental { return fmt.Errorf("%s is only supported on a Docker daemon with experimental features enabled", cmd.CommandPath()) } if _, ok := curr.Annotations["experimentalCLI"]; ok && !hasExperimentalCLI { return fmt.Errorf("%s is only supported on a Docker cli with experimental cli features enabled", cmd.CommandPath()) } } return nil } func getFlagAnnotation(f *pflag.Flag, annotation string) string { if value, ok := f.Annotations[annotation]; ok && len(value) == 1 { return value[0] } return "" } func isVersionSupported(f *pflag.Flag, clientVersion string) bool { if v := getFlagAnnotation(f, "version"); v != "" { return versions.GreaterThanOrEqualTo(clientVersion, v) } return true } func isOSTypeSupported(f *pflag.Flag, osType string) bool { if v := getFlagAnnotation(f, "ostype"); v != "" && osType != "" { return osType == v } return true } // hasTags return true if any of the command's parents has tags func hasTags(cmd *cobra.Command) bool { for curr := cmd; curr != nil; curr = curr.Parent() { if len(curr.Annotations) > 0 { return true } } return false }