plugins: experimental support for new plugin management

This patch introduces a new experimental engine-level plugin management
with a new API and command line. Plugins can be distributed via a Docker
registry, and their lifecycle is managed by the engine.
This makes plugins a first-class construct.

For more background, have a look at issue docker#20363.

Documentation is in a separate commit. If you want to understand how the
new plugin system works, you can start by reading the documentation.

Note: backwards compatibility with existing plugins is maintained,
albeit they won't benefit from the advantages of the new system.

Signed-off-by: Tibor Vass <[email protected]>
Signed-off-by: Anusha Ragunathan <[email protected]>

api/client/plugin/cmd.go

@@ -0,0 +1,12 @@
+// +build !experimental
+
+package plugin
+
+import (
+	"github.com/docker/docker/api/client"
+	"github.com/spf13/cobra"
+)
+
+// NewPluginCommand returns a cobra command for `plugin` subcommands
+func NewPluginCommand(cmd *cobra.Command, dockerCli *client.DockerCli) {
+}

api/client/plugin/cmd_experimental.go

@@ -0,0 +1,36 @@
+// +build experimental
+
+package plugin
+
+import (
+	"fmt"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+)
+
+// NewPluginCommand returns a cobra command for `plugin` subcommands
+func NewPluginCommand(rootCmd *cobra.Command, dockerCli *client.DockerCli) {
+	cmd := &cobra.Command{
+		Use:   "plugin",
+		Short: "Manage Docker plugins",
+		Args:  cli.NoArgs,
+		Run: func(cmd *cobra.Command, args []string) {
+			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())
+		},
+	}
+
+	cmd.AddCommand(
+		newDisableCommand(dockerCli),
+		newEnableCommand(dockerCli),
+		newInspectCommand(dockerCli),
+		newInstallCommand(dockerCli),
+		newListCommand(dockerCli),
+		newRemoveCommand(dockerCli),
+		newSetCommand(dockerCli),
+		newPushCommand(dockerCli),
+	)
+
+	rootCmd.AddCommand(cmd)
+}

api/client/plugin/disable.go

@@ -0,0 +1,23 @@
+// +build experimental
+
+package plugin
+
+import (
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+func newDisableCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "disable",
+		Short: "Disable a plugin",
+		Args:  cli.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return dockerCli.Client().PluginDisable(context.Background(), args[0])
+		},
+	}
+
+	return cmd
+}

api/client/plugin/enable.go

@@ -0,0 +1,23 @@
+// +build experimental
+
+package plugin
+
+import (
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+func newEnableCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "enable",
+		Short: "Enable a plugin",
+		Args:  cli.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return dockerCli.Client().PluginEnable(context.Background(), args[0])
+		},
+	}
+
+	return cmd
+}

api/client/plugin/inspect.go

@@ -0,0 +1,39 @@
+// +build experimental
+
+package plugin
+
+import (
+	"encoding/json"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+func newInspectCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "inspect",
+		Short: "Inspect a plugin",
+		Args:  cli.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runInspect(dockerCli, args[0])
+		},
+	}
+
+	return cmd
+}
+
+func runInspect(dockerCli *client.DockerCli, name string) error {
+	p, err := dockerCli.Client().PluginInspect(context.Background(), name)
+	if err != nil {
+		return err
+	}
+
+	b, err := json.MarshalIndent(p, "", "\t")
+	if err != nil {
+		return err
+	}
+	_, err = dockerCli.Out().Write(b)
+	return err
+}

api/client/plugin/install.go

@@ -0,0 +1,51 @@
+// +build experimental
+
+package plugin
+
+import (
+	"fmt"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/docker/docker/reference"
+	"github.com/docker/docker/registry"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+func newInstallCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "install",
+		Short: "Install a plugin",
+		Args:  cli.RequiresMinArgs(1), // TODO: allow for set args
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runInstall(dockerCli, args[0], args[1:])
+		},
+	}
+
+	return cmd
+}
+
+func runInstall(dockerCli *client.DockerCli, name string, args []string) error {
+	named, err := reference.ParseNamed(name) // FIXME: validate
+	if err != nil {
+		return err
+	}
+	named = reference.WithDefaultTag(named)
+	ref, ok := named.(reference.NamedTagged)
+	if !ok {
+		return fmt.Errorf("invalid name: %s", named.String())
+	}
+
+	ctx := context.Background()
+
+	repoInfo, err := registry.ParseRepositoryInfo(named)
+	authConfig := dockerCli.ResolveAuthConfig(ctx, repoInfo.Index)
+
+	encodedAuth, err := client.EncodeAuthToBase64(authConfig)
+	if err != nil {
+		return err
+	}
+	// TODO: pass acceptAllPermissions and noEnable flag
+	return dockerCli.Client().PluginInstall(ctx, ref.String(), encodedAuth, false, false, dockerCli.In(), dockerCli.Out())
+}

api/client/plugin/list.go

@@ -0,0 +1,44 @@
+// +build experimental
+
+package plugin
+
+import (
+	"fmt"
+	"text/tabwriter"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+func newListCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "ls",
+		Short:   "List plugins",
+		Aliases: []string{"list"},
+		Args:    cli.ExactArgs(0),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runList(dockerCli)
+		},
+	}
+
+	return cmd
+}
+
+func runList(dockerCli *client.DockerCli) error {
+	plugins, err := dockerCli.Client().PluginList(context.Background())
+	if err != nil {
+		return err
+	}
+
+	w := tabwriter.NewWriter(dockerCli.Out(), 20, 1, 3, ' ', 0)
+	fmt.Fprintf(w, "NAME \tTAG \tACTIVE")
+	fmt.Fprintf(w, "\n")
+
+	for _, p := range plugins {
+		fmt.Fprintf(w, "%s\t%s\t%v\n", p.Name, p.Tag, p.Active)
+	}
+	w.Flush()
+	return nil
+}

api/client/plugin/push.go

@@ -0,0 +1,50 @@
+// +build experimental
+
+package plugin
+
+import (
+	"fmt"
+
+	"golang.org/x/net/context"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/docker/docker/reference"
+	"github.com/docker/docker/registry"
+	"github.com/spf13/cobra"
+)
+
+func newPushCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "push",
+		Short: "Push a plugin",
+		Args:  cli.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runPush(dockerCli, args[0])
+		},
+	}
+	return cmd
+}
+
+func runPush(dockerCli *client.DockerCli, name string) error {
+	named, err := reference.ParseNamed(name) // FIXME: validate
+	if err != nil {
+		return err
+	}
+	named = reference.WithDefaultTag(named)
+	ref, ok := named.(reference.NamedTagged)
+	if !ok {
+		return fmt.Errorf("invalid name: %s", named.String())
+	}
+
+	ctx := context.Background()
+
+	repoInfo, err := registry.ParseRepositoryInfo(named)
+	authConfig := dockerCli.ResolveAuthConfig(ctx, repoInfo.Index)
+
+	encodedAuth, err := client.EncodeAuthToBase64(authConfig)
+	if err != nil {
+		return err
+	}
+	return dockerCli.Client().PluginPush(ctx, ref.String(), encodedAuth)
+}

api/client/plugin/remove.go

@@ -0,0 +1,43 @@
+// +build experimental
+
+package plugin
+
+import (
+	"fmt"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+func newRemoveCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "rm",
+		Short:   "Remove a plugin",
+		Aliases: []string{"remove"},
+		Args:    cli.RequiresMinArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runRemove(dockerCli, args)
+		},
+	}
+
+	return cmd
+}
+
+func runRemove(dockerCli *client.DockerCli, names []string) error {
+	var errs cli.Errors
+	for _, name := range names {
+		// TODO: pass names to api instead of making multiple api calls
+		if err := dockerCli.Client().PluginRemove(context.Background(), name); err != nil {
+			errs = append(errs, err)
+			continue
+		}
+		fmt.Fprintln(dockerCli.Out(), name)
+	}
+	// Do not simplify to `return errs` because even if errs == nil, it is not a nil-error interface value.
+	if errs != nil {
+		return errs
+	}
+	return nil
+}

api/client/plugin/set.go

@@ -0,0 +1,28 @@
+// +build experimental
+
+package plugin
+
+import (
+	"golang.org/x/net/context"
+
+	"github.com/docker/docker/api/client"
+	"github.com/docker/docker/cli"
+	"github.com/spf13/cobra"
+)
+
+func newSetCommand(dockerCli *client.DockerCli) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "set",
+		Short: "Change settings for a plugin",
+		Args:  cli.RequiresMinArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runSet(dockerCli, args[0], args[1:])
+		},
+	}
+
+	return cmd
+}
+
+func runSet(dockerCli *client.DockerCli, name string, args []string) error {
+	return dockerCli.Client().PluginSet(context.Background(), name, args)
+}

api/server/router/plugin/backend.go

@@ -0,0 +1,21 @@
+// +build experimental
+
+package plugin
+
+import (
+	"net/http"
+
+	enginetypes "github.com/docker/engine-api/types"
+)
+
+// Backend for Plugin
+type Backend interface {
+	Disable(name string) error
+	Enable(name string) error
+	List() ([]enginetypes.Plugin, error)
+	Inspect(name string) (enginetypes.Plugin, error)
+	Remove(name string) error
+	Set(name string, args []string) error
+	Pull(name string, metaHeaders http.Header, authConfig *enginetypes.AuthConfig) (enginetypes.PluginPrivileges, error)
+	Push(name string, metaHeaders http.Header, authConfig *enginetypes.AuthConfig) error
+}