Always enable experimental features

The CLI disabled experimental features by default, requiring users
to set a configuration option to enable them.

Disabling experimental features was a request from Enterprise users
that did not want experimental features to be accessible.

We are changing this policy, and now enable experimental features
by default. Experimental features may still change and/or removed,
and will be highlighted in the documentation and "usage" output.

For example, the `docker manifest inspect --help` output now shows:

    EXPERIMENTAL:
      docker manifest inspect is an experimental feature.

      Experimental features provide early access to product functionality. These features
      may change between releases without warning or can be removed entirely from a future
      release. Learn more about experimental features: https://docs.docker.com/go/experimental/

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli-plugins/examples/helloworld/main.go

@@ -101,6 +101,5 @@ func main() {
 			SchemaVersion: "0.1.0",
 			Vendor:        "Docker Inc.",
 			Version:       "testing",
-			Experimental:  os.Getenv("HELLO_EXPERIMENTAL") != "",
 		})
 }

cli-plugins/manager/candidate_test.go

@@ -12,10 +12,9 @@ import (
 )
 
 type fakeCandidate struct {
-	path              string
-	exec              bool
-	meta              string
-	allowExperimental bool
+	path string
+	exec bool
+	meta string
 }
 
 func (c *fakeCandidate) Path() string {
@@ -30,7 +29,7 @@ func (c *fakeCandidate) Metadata() ([]byte, error) {
 }
 
 func TestValidateCandidate(t *testing.T) {
-	var (
+	const (
 		goodPluginName = NamePrefix + "goodplugin"
 
 		builtinName  = NamePrefix + "builtin"
@@ -70,14 +69,12 @@ func TestValidateCandidate(t *testing.T) {
 		{name: "invalid schemaversion", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: `{"SchemaVersion": "xyzzy"}`}, invalid: `plugin SchemaVersion "xyzzy" is not valid`},
 		{name: "no vendor", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: `{"SchemaVersion": "0.1.0"}`}, invalid: "plugin metadata does not define a vendor"},
 		{name: "empty vendor", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: `{"SchemaVersion": "0.1.0", "Vendor": ""}`}, invalid: "plugin metadata does not define a vendor"},
-		{name: "experimental required", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: metaExperimental}, invalid: "requires experimental CLI"},
 		// This one should work
 		{name: "valid", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: `{"SchemaVersion": "0.1.0", "Vendor": "e2e-testing"}`}},
-		{name: "valid + allowing experimental", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: `{"SchemaVersion": "0.1.0", "Vendor": "e2e-testing"}`, allowExperimental: true}},
-		{name: "experimental + allowing experimental", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: metaExperimental, allowExperimental: true}},
+		{name: "experimental + allowing experimental", c: &fakeCandidate{path: goodPluginPath, exec: true, meta: metaExperimental}},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			p, err := newPlugin(tc.c, fakeroot, tc.c.allowExperimental)
+			p, err := newPlugin(tc.c, fakeroot)
 			if tc.err != "" {
 				assert.ErrorContains(t, err, tc.err)
 			} else if tc.invalid != "" {

cli-plugins/manager/manager.go

@@ -1,7 +1,6 @@
 package manager
 
 import (
-	"fmt"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -30,16 +29,6 @@ func (e errPluginNotFound) Error() string {
 	return "Error: No such CLI plugin: " + string(e)
 }
 
-type errPluginRequireExperimental string
-
-// Note: errPluginRequireExperimental implements notFound so that the plugin
-// is skipped when listing the plugins.
-func (e errPluginRequireExperimental) NotFound() {}
-
-func (e errPluginRequireExperimental) Error() string {
-	return fmt.Sprintf("plugin candidate %q: requires experimental CLI", string(e))
-}
-
 type notFound interface{ NotFound() }
 
 // IsNotFound is true if the given error is due to a plugin not being found.
@@ -133,7 +122,7 @@ func ListPlugins(dockerCli command.Cli, rootcmd *cobra.Command) ([]Plugin, error
 			continue
 		}
 		c := &candidate{paths[0]}
-		p, err := newPlugin(c, rootcmd, dockerCli.ClientInfo().HasExperimental)
+		p, err := newPlugin(c, rootcmd)
 		if err != nil {
 			return nil, err
 		}
@@ -181,19 +170,12 @@ func PluginRunCommand(dockerCli command.Cli, name string, rootcmd *cobra.Command
 		}
 
 		c := &candidate{path: path}
-		plugin, err := newPlugin(c, rootcmd, dockerCli.ClientInfo().HasExperimental)
+		plugin, err := newPlugin(c, rootcmd)
 		if err != nil {
 			return nil, err
 		}
 		if plugin.Err != nil {
 			// TODO: why are we not returning plugin.Err?
-
-			err := plugin.Err.(*pluginError).Cause()
-			// if an experimental plugin was invoked directly while experimental mode is off
-			// provide a more useful error message than "not found".
-			if err, ok := err.(errPluginRequireExperimental); ok {
-				return nil, err
-			}
 			return nil, errPluginNotFound(name)
 		}
 		cmd := exec.Command(plugin.Path, args...)

cli-plugins/manager/metadata.go

@@ -23,6 +23,6 @@ type Metadata struct {
 	// URL is a pointer to the plugin's homepage.
 	URL string `json:",omitempty"`
 	// Experimental specifies whether the plugin is experimental.
-	// Experimental plugins are not displayed on non-experimental CLIs.
+	// Deprecated: experimental features are now always enabled in the CLI
 	Experimental bool `json:",omitempty"`
 }

cli-plugins/manager/plugin.go

@@ -35,7 +35,7 @@ type Plugin struct {
 // non-recoverable error.
 //
 // nolint: gocyclo
-func newPlugin(c Candidate, rootcmd *cobra.Command, allowExperimental bool) (Plugin, error) {
+func newPlugin(c Candidate, rootcmd *cobra.Command) (Plugin, error) {
 	path := c.Path()
 	if path == "" {
 		return Plugin{}, errors.New("plugin candidate path cannot be empty")
@@ -96,10 +96,6 @@ func newPlugin(c Candidate, rootcmd *cobra.Command, allowExperimental bool) (Plu
 		p.Err = wrapAsPluginError(err, "invalid metadata")
 		return p, nil
 	}
-	if p.Experimental && !allowExperimental {
-		p.Err = &pluginError{errPluginRequireExperimental(p.Name)}
-		return p, nil
-	}
 	if p.Metadata.SchemaVersion != "0.1.0" {
 		p.Err = NewPluginError("plugin SchemaVersion %q is not valid, must be 0.1.0", p.Metadata.SchemaVersion)
 		return p, nil