Create a new ServerType struct for storing details about the server on the client.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

cli/command/cli.go

@@ -44,28 +44,17 @@ type Cli interface {
 // DockerCli is an instance the docker command line client.
 // Instances of the client can be returned from NewDockerCli.
 type DockerCli struct {
-	configFile      *configfile.ConfigFile
-	in              *InStream
-	out             *OutStream
-	err             io.Writer
-	keyFile         string
-	client          client.APIClient
-	hasExperimental bool
-	osType          string
-	defaultVersion  string
+	configFile     *configfile.ConfigFile
+	in             *InStream
+	out            *OutStream
+	err            io.Writer
+	keyFile        string
+	client         client.APIClient
+	defaultVersion string
+	server         ServerInfo
 }
 
-// HasExperimental returns true if experimental features are accessible.
-func (cli *DockerCli) HasExperimental() bool {
-	return cli.hasExperimental
-}
-
-// OSType returns the operating system the daemon is running on.
-func (cli *DockerCli) OSType() string {
-	return cli.osType
-}
-
-// DefaultVersion returns api.defaultVersion of DOCKER_API_VERSION if specified.
+// DefaultVersion returns api.defaultVersion or DOCKER_API_VERSION if specified.
 func (cli *DockerCli) DefaultVersion() string {
 	return cli.defaultVersion
 }
@@ -102,6 +91,12 @@ func (cli *DockerCli) ConfigFile() *configfile.ConfigFile {
 	return cli.configFile
 }
 
+// ServerInfo returns the server version details for the host this client is
+// connected to
+func (cli *DockerCli) ServerInfo() ServerInfo {
+	return cli.server
+}
+
 // GetAllCredentials returns all of the credentials stored in all of the
 // configured credential stores.
 func (cli *DockerCli) GetAllCredentials() (map[string]types.AuthConfig, error) {
@@ -161,7 +156,6 @@ func (cli *DockerCli) Initialize(opts *cliflags.ClientOptions) error {
 	if err != nil {
 		return err
 	}
-
 	cli.defaultVersion = cli.client.ClientVersion()
 
 	if opts.Common.TrustKey == "" {
@@ -171,8 +165,10 @@ func (cli *DockerCli) Initialize(opts *cliflags.ClientOptions) error {
 	}
 
 	if ping, err := cli.client.Ping(context.Background()); err == nil {
-		cli.hasExperimental = ping.Experimental
-		cli.osType = ping.OSType
+		cli.server = ServerInfo{
+			HasExperimental: ping.Experimental,
+			OSType:          ping.OSType,
+		}
 
 		// since the new header was added in 1.25, assume server is 1.24 if header is not present.
 		if ping.APIVersion == "" {
@@ -184,9 +180,17 @@ func (cli *DockerCli) Initialize(opts *cliflags.ClientOptions) error {
 			cli.client.UpdateClientVersion(ping.APIVersion)
 		}
 	}
+
 	return nil
 }
 
+// ServerInfo stores details about the supported features and platform of the
+// server
+type ServerInfo struct {
+	HasExperimental bool
+	OSType          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}

cmd/docker/docker.go

@@ -14,6 +14,7 @@ import (
 	cliconfig "github.com/docker/docker/cli/config"
 	"github.com/docker/docker/cli/debug"
 	cliflags "github.com/docker/docker/cli/flags"
+	"github.com/docker/docker/client"
 	"github.com/docker/docker/dockerversion"
 	"github.com/docker/docker/pkg/term"
 	"github.com/spf13/cobra"
@@ -49,7 +50,7 @@ func newDockerCommand(dockerCli *command.DockerCli) *cobra.Command {
 			if err := dockerCli.Initialize(opts); err != nil {
 				return err
 			}
-			return isSupported(cmd, dockerCli.Client().ClientVersion(), dockerCli.OSType(), dockerCli.HasExperimental())
+			return isSupported(cmd, dockerCli)
 		},
 	}
 	cli.SetupRootCommand(cmd)
@@ -80,7 +81,7 @@ func setFlagErrorFunc(dockerCli *command.DockerCli, cmd *cobra.Command, flags *p
 	flagErrorFunc := cmd.FlagErrorFunc()
 	cmd.SetFlagErrorFunc(func(cmd *cobra.Command, err error) error {
 		initializeDockerCli(dockerCli, flags, opts)
-		if err := isSupported(cmd, dockerCli.Client().ClientVersion(), dockerCli.OSType(), dockerCli.HasExperimental()); err != nil {
+		if err := isSupported(cmd, dockerCli); err != nil {
 			return err
 		}
 		return flagErrorFunc(cmd, err)
@@ -90,12 +91,12 @@ func setFlagErrorFunc(dockerCli *command.DockerCli, cmd *cobra.Command, flags *p
 func setHelpFunc(dockerCli *command.DockerCli, cmd *cobra.Command, flags *pflag.FlagSet, opts *cliflags.ClientOptions) {
 	cmd.SetHelpFunc(func(ccmd *cobra.Command, args []string) {
 		initializeDockerCli(dockerCli, flags, opts)
-		if err := isSupported(ccmd, dockerCli.Client().ClientVersion(), dockerCli.OSType(), dockerCli.HasExperimental()); err != nil {
+		if err := isSupported(ccmd, dockerCli); err != nil {
 			ccmd.Println(err)
 			return
 		}
 
-		hideUnsupportedFeatures(ccmd, dockerCli.Client().ClientVersion(), dockerCli.OSType(), dockerCli.HasExperimental())
+		hideUnsupportedFeatures(ccmd, dockerCli)
 
 		if err := ccmd.Help(); err != nil {
 			ccmd.Println(err)
@@ -122,7 +123,7 @@ func setValidateArgs(dockerCli *command.DockerCli, cmd *cobra.Command, flags *pf
 		cmdArgs := ccmd.Args
 		ccmd.Args = func(cmd *cobra.Command, args []string) error {
 			initializeDockerCli(dockerCli, flags, opts)
-			if err := isSupported(cmd, dockerCli.Client().ClientVersion(), dockerCli.OSType(), dockerCli.HasExperimental()); err != nil {
+			if err := isSupported(cmd, dockerCli); err != nil {
 				return err
 			}
 			return cmdArgs(cmd, args)
@@ -198,7 +199,16 @@ func dockerPreRun(opts *cliflags.ClientOptions) {
 	}
 }
 
-func hideUnsupportedFeatures(cmd *cobra.Command, clientVersion, osType string, hasExperimental bool) {
+type versionDetails interface {
+	Client() client.APIClient
+	ServerInfo() command.ServerInfo
+}
+
+func hideUnsupportedFeatures(cmd *cobra.Command, details versionDetails) {
+	clientVersion := details.Client().ClientVersion()
+	osType := details.ServerInfo().OSType
+	hasExperimental := details.ServerInfo().HasExperimental
+
 	cmd.Flags().VisitAll(func(f *pflag.Flag) {
 		// hide experimental flags
 		if !hasExperimental {
@@ -228,7 +238,11 @@ func hideUnsupportedFeatures(cmd *cobra.Command, clientVersion, osType string, h
 	}
 }
 
-func isSupported(cmd *cobra.Command, clientVersion, osType string, hasExperimental bool) error {
+func isSupported(cmd *cobra.Command, details versionDetails) error {
+	clientVersion := details.Client().ClientVersion()
+	osType := details.ServerInfo().OSType
+	hasExperimental := details.ServerInfo().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.Tags["version"]; ok && versions.LessThan(clientVersion, cmdVersion) {