Add support for experimental Cli configuration

Allow to mark some commands and flags experimental on cli (i.e. not
depending to the state of the daemon). This will allow more flexibility
on experimentation with the cli.

Marking `docker trust` as cli experimental as it is documented so.

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

cli/command/cli.go

@@ -42,6 +42,7 @@ type Cli interface {
 	SetIn(in *InStream)
 	ConfigFile() *configfile.ConfigFile
 	ServerInfo() ServerInfo
+	ClientInfo() ClientInfo
 	NotaryClient(imgRefAndAuth trust.ImageRefAndAuth, actions []string) (notaryclient.Repository, error)
 }
 
@@ -53,13 +54,13 @@ type DockerCli struct {
 	out        *OutStream
 	err        io.Writer
 	client     client.APIClient
-	defaultVersion string
-	server         ServerInfo
+	serverInfo ServerInfo
+	clientInfo ClientInfo
 }
 
 // DefaultVersion returns api.defaultVersion or DOCKER_API_VERSION if specified.
 func (cli *DockerCli) DefaultVersion() string {
-	return cli.defaultVersion
+	return cli.clientInfo.DefaultVersion
 }
 
 // Client returns the APIClient
@@ -104,7 +105,12 @@ func (cli *DockerCli) ConfigFile() *configfile.ConfigFile {
 // ServerInfo returns the server version details for the host this client is
 // connected to
 func (cli *DockerCli) ServerInfo() ServerInfo {
-	return cli.server
+	return cli.serverInfo
+}
+
+// ClientInfo returns the client details for the cli
+func (cli *DockerCli) ClientInfo() ClientInfo {
+	return cli.clientInfo
 }
 
 // Initialize the dockerCli runs initialization that must happen after command
@@ -125,17 +131,34 @@ func (cli *DockerCli) Initialize(opts *cliflags.ClientOptions) error {
 	if err != nil {
 		return err
 	}
+	hasExperimental, err := isEnabled(cli.configFile.Experimental)
+	if err != nil {
+		return errors.Wrap(err, "Experimental field")
+	}
+	cli.clientInfo = ClientInfo{
+		DefaultVersion:  cli.client.ClientVersion(),
+		HasExperimental: hasExperimental,
+	}
 	cli.initializeFromClient()
 	return nil
 }
 
-func (cli *DockerCli) initializeFromClient() {
-	cli.defaultVersion = cli.client.ClientVersion()
+func isEnabled(value string) (bool, error) {
+	switch value {
+	case "enabled":
+		return true, nil
+	case "", "disabled":
+		return false, nil
+	default:
+		return false, errors.Errorf("%q is not valid, should be either enabled or disabled", value)
+	}
+}
 
+func (cli *DockerCli) initializeFromClient() {
 	ping, err := cli.client.Ping(context.Background())
 	if err != nil {
 		// Default to true if we fail to connect to daemon
-		cli.server = ServerInfo{HasExperimental: true}
+		cli.serverInfo = ServerInfo{HasExperimental: true}
 
 		if ping.APIVersion != "" {
 			cli.client.NegotiateAPIVersionPing(ping)
@@ -143,7 +166,7 @@ func (cli *DockerCli) initializeFromClient() {
 		return
 	}
 
-	cli.server = ServerInfo{
+	cli.serverInfo = ServerInfo{
 		HasExperimental: ping.Experimental,
 		OSType:          ping.OSType,
 	}
@@ -176,6 +199,12 @@ type ServerInfo struct {
 	OSType          string
 }
 
+// ClientInfo stores details about the supported features of the client
+type ClientInfo struct {
+	HasExperimental bool
+	DefaultVersion  string
+}
+
 // NewDockerCli returns a DockerCli instance with IO output and error streams set by in, out and err.
 func NewDockerCli(in io.ReadCloser, out, err io.Writer) *DockerCli {
 	return &DockerCli{in: NewInStream(in), out: NewOutStream(out), err: err}

cli/command/cli_test.go

@@ -1,17 +1,18 @@
 package command
 
 import (
+	"crypto/x509"
 	"os"
 	"testing"
 
-	"crypto/x509"
-
+	cliconfig "github.com/docker/cli/cli/config"
 	"github.com/docker/cli/cli/config/configfile"
 	"github.com/docker/cli/cli/flags"
 	"github.com/docker/cli/internal/test/testutil"
 	"github.com/docker/docker/api"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
+	"github.com/gotestyourself/gotestyourself/fs"
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -124,13 +125,51 @@ func TestInitializeFromClient(t *testing.T) {
 
 			cli := &DockerCli{client: apiclient}
 			cli.initializeFromClient()
-			assert.Equal(t, defaultVersion, cli.defaultVersion)
-			assert.Equal(t, testcase.expectedServer, cli.server)
+			assert.Equal(t, testcase.expectedServer, cli.serverInfo)
 			assert.Equal(t, testcase.negotiated, apiclient.negotiated)
 		})
 	}
 }
 
+func TestExperimentalCLI(t *testing.T) {
+	defaultVersion := "v1.55"
+
+	var testcases = []struct {
+		doc                     string
+		configfile              string
+		expectedExperimentalCLI bool
+	}{
+		{
+			doc:                     "default",
+			configfile:              `{}`,
+			expectedExperimentalCLI: false,
+		},
+		{
+			doc: "experimental",
+			configfile: `{
+	"experimental": "enabled"
+}`,
+			expectedExperimentalCLI: true,
+		},
+	}
+
+	for _, testcase := range testcases {
+		t.Run(testcase.doc, func(t *testing.T) {
+			dir := fs.NewDir(t, testcase.doc, fs.WithFile("config.json", testcase.configfile))
+			defer dir.Remove()
+			apiclient := &fakeClient{
+				version: defaultVersion,
+			}
+
+			cli := &DockerCli{client: apiclient, err: os.Stderr}
+			cliconfig.SetDir(dir.Path())
+			err := cli.Initialize(flags.NewClientOptions())
+			assert.NoError(t, err)
+			assert.Equal(t, testcase.expectedExperimentalCLI, cli.ClientInfo().HasExperimental)
+		})
+	}
+}
+
 func TestGetClientWithPassword(t *testing.T) {
 	expected := "password"
 

cli/command/system/version.go

@@ -23,6 +23,7 @@ Client:{{if ne .Platform.Name ""}} {{.Platform.Name}}{{end}}
  Git commit:	{{.GitCommit}}
  Built:	{{.BuildTime}}
  OS/Arch:	{{.Os}}/{{.Arch}}
+ Experimental:	{{.Experimental}}
 {{- end}}
 
 {{- if .ServerOK}}{{with .Server}}
@@ -69,6 +70,7 @@ type clientVersion struct {
 	Os                string
 	Arch              string
 	BuildTime         string `json:",omitempty"`
+	Experimental      bool
 }
 
 // ServerOK returns true when the client could connect to the docker server
@@ -133,6 +135,7 @@ func runVersion(dockerCli *command.DockerCli, opts *versionOptions) error {
 			BuildTime:         cli.BuildTime,
 			Os:                runtime.GOOS,
 			Arch:              runtime.GOARCH,
+			Experimental:      dockerCli.ClientInfo().HasExperimental,
 		},
 	}
 	vd.Client.Platform.Name = cli.PlatformName

cli/command/trust/cmd.go

@@ -13,6 +13,7 @@ func NewTrustCommand(dockerCli command.Cli) *cobra.Command {
 		Short:       "Manage trust on Docker images (experimental)",
 		Args:        cli.NoArgs,
 		RunE:        command.ShowHelp(dockerCli.Err()),
+		Annotations: map[string]string{"experimentalCLI": ""},
 	}
 	cmd.AddCommand(
 		newViewCommand(dockerCli),

cli/config/configfile/file.go

@@ -44,6 +44,7 @@ type ConfigFile struct {
 	NodesFormat          string                      `json:"nodesFormat,omitempty"`
 	PruneFilters         []string                    `json:"pruneFilters,omitempty"`
 	Proxies              map[string]ProxyConfig      `json:"proxies,omitempty"`
+	Experimental         string                      `json:"experimental,omitempty"`
 }
 
 // ProxyConfig contains proxy configuration settings

cmd/docker/docker.go

@@ -193,6 +193,7 @@ func dockerPreRun(opts *cliflags.ClientOptions) {
 
 type versionDetails interface {
 	Client() client.APIClient
+	ClientInfo() command.ClientInfo
 	ServerInfo() command.ServerInfo
 }
 
@@ -200,6 +201,7 @@ func hideUnsupportedFeatures(cmd *cobra.Command, details versionDetails) {
 	clientVersion := details.Client().ClientVersion()
 	osType := details.ServerInfo().OSType
 	hasExperimental := details.ServerInfo().HasExperimental
+	hasExperimentalCLI := details.ClientInfo().HasExperimental
 
 	cmd.Flags().VisitAll(func(f *pflag.Flag) {
 		// hide experimental flags
@@ -208,6 +210,11 @@ func hideUnsupportedFeatures(cmd *cobra.Command, details versionDetails) {
 				f.Hidden = true
 			}
 		}
+		if !hasExperimentalCLI {
+			if _, ok := f.Annotations["experimentalCLI"]; ok {
+				f.Hidden = true
+			}
+		}
 
 		// hide flags not supported by the server
 		if !isOSTypeSupported(f, osType) || !isVersionSupported(f, clientVersion) {
@@ -222,6 +229,11 @@ func hideUnsupportedFeatures(cmd *cobra.Command, details versionDetails) {
 				subcmd.Hidden = true
 			}
 		}
+		if !hasExperimentalCLI {
+			if _, ok := subcmd.Annotations["experimentalCLI"]; ok {
+				subcmd.Hidden = true
+			}
+		}
 
 		// hide subcommands not supported by the server
 		if subcmdVersion, ok := subcmd.Annotations["version"]; ok && versions.LessThan(clientVersion, subcmdVersion) {
@@ -234,6 +246,7 @@ func isSupported(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() {
@@ -243,6 +256,9 @@ func isSupported(cmd *cobra.Command, details versionDetails) error {
 		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 when experimental cli features are enabled", cmd.CommandPath())
+		}
 	}
 
 	errs := []string{}
@@ -260,6 +276,9 @@ func isSupported(cmd *cobra.Command, details versionDetails) error {
 			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 only supported when experimental cli features are enabled", f.Name))
+			}
 		}
 	})
 	if len(errs) > 0 {

e2e/internal/fixtures/fixtures.go

@@ -32,7 +32,8 @@ func SetupConfigFile(t *testing.T) fs.Dir {
 			"https://notary-server:4443": {
 				"auth": "ZWlhaXM6cGFzc3dvcmQK"
 			}
-		}
+		},
+		"experimental": "enabled"
 	}
 	`))
 	return *dir