From b867f6c6e18f9d999ddec911a241941428777569 Mon Sep 17 00:00:00 2001
From: Anusha Ragunathan <anusha@docker.com>
Date: Mon, 25 Jul 2016 14:06:27 -0700
Subject: [PATCH] Check for plugin state before enable and disable.

This prevents unnecessary API call to containerd.

Signed-off-by: Anusha Ragunathan <anusha@docker.com>
---
 integration-cli/docker_cli_plugins_test.go | 21 +++++++++++++++++++++
 plugin/manager_linux.go                    | 13 +++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/integration-cli/docker_cli_plugins_test.go b/integration-cli/docker_cli_plugins_test.go
index bedeff6ecc..ca1b7d2b8f 100644
--- a/integration-cli/docker_cli_plugins_test.go
+++ b/integration-cli/docker_cli_plugins_test.go
@@ -68,3 +68,24 @@ func (s *DockerSuite) TestPluginInstallImage(c *check.C) {
 	c.Assert(err, checker.NotNil)
 	c.Assert(out, checker.Contains, "content is not a plugin")
 }
+
+func (s *DockerSuite) TestPluginEnableDisableNegative(c *check.C) {
+	testRequires(c, DaemonIsLinux, ExperimentalDaemon)
+	out, _, err := dockerCmdWithError("plugin", "install", "--grant-all-permissions", pName)
+	c.Assert(err, checker.IsNil)
+	c.Assert(strings.TrimSpace(out), checker.Contains, pName)
+
+	out, _, err = dockerCmdWithError("plugin", "enable", pName)
+	c.Assert(err, checker.NotNil)
+	c.Assert(strings.TrimSpace(out), checker.Contains, "already enabled")
+
+	_, _, err = dockerCmdWithError("plugin", "disable", pName)
+	c.Assert(err, checker.IsNil)
+
+	out, _, err = dockerCmdWithError("plugin", "disable", pName)
+	c.Assert(err, checker.NotNil)
+	c.Assert(strings.TrimSpace(out), checker.Contains, "already disabled")
+
+	_, _, err = dockerCmdWithError("plugin", "remove", pName)
+	c.Assert(err, checker.IsNil)
+}
diff --git a/plugin/manager_linux.go b/plugin/manager_linux.go
index 2ce7470405..b50415b124 100644
--- a/plugin/manager_linux.go
+++ b/plugin/manager_linux.go
@@ -3,6 +3,7 @@
 package plugin
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"syscall"
@@ -20,6 +21,9 @@ import (
 )
 
 func (pm *Manager) enable(p *plugin) error {
+	if p.P.Active {
+		return fmt.Errorf("plugin %s is already enabled", p.Name())
+	}
 	spec, err := pm.initSpec(p)
 	if err != nil {
 		return err
@@ -27,12 +31,18 @@ func (pm *Manager) enable(p *plugin) error {
 
 	p.restartManager = restartmanager.New(container.RestartPolicy{Name: "always"}, 0)
 	if err := pm.containerdClient.Create(p.P.ID, libcontainerd.Spec(*spec), libcontainerd.WithRestartManager(p.restartManager)); err != nil { // POC-only
+		if err := p.restartManager.Cancel(); err != nil {
+			logrus.Errorf("enable: restartManager.Cancel failed due to %v", err)
+		}
 		return err
 	}
 
 	socket := p.P.Manifest.Interface.Socket
 	p.client, err = plugins.NewClient("unix://"+filepath.Join(p.runtimeSourcePath, socket), nil)
 	if err != nil {
+		if err := p.restartManager.Cancel(); err != nil {
+			logrus.Errorf("enable: restartManager.Cancel failed due to %v", err)
+		}
 		return err
 	}
 
@@ -114,6 +124,9 @@ func (pm *Manager) initSpec(p *plugin) (*specs.Spec, error) {
 }
 
 func (pm *Manager) disable(p *plugin) error {
+	if !p.P.Active {
+		return fmt.Errorf("plugin %s is already disabled", p.Name())
+	}
 	if err := p.restartManager.Cancel(); err != nil {
 		logrus.Error(err)
 	}