Implement experimental REST API endpoints for plugins (#7279)

* Implement experimental REST API endpoints for plugins

* Updates per feedback and rebase

* Update tests

* Further updates

* Update extraction of plugins

* Use OS temp dir for plugins instead of search path

* Fail extraction on paths that attempt to traverse upward

* Update pluginenv ActivePlugins()

6 files changed, 171 insertions, 65 deletions

diff --git a/plugin/pluginenv/environment.go b/plugin/pluginenv/environment.go
index 36a8c6e76..ebda0e0db 100644
--- a/plugin/pluginenv/environment.go
+++ b/plugin/pluginenv/environment.go
@@ -3,21 +3,31 @@ package pluginenv
 
 import (
 	"fmt"
+	"io/ioutil"
+	"sync"
 
 	"github.com/pkg/errors"
 
+	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/plugin"
 )
 
-type APIProviderFunc func(*plugin.Manifest) (plugin.API, error)
-type SupervisorProviderFunc func(*plugin.BundleInfo) (plugin.Supervisor, error)
+type APIProviderFunc func(*model.Manifest) (plugin.API, error)
+type SupervisorProviderFunc func(*model.BundleInfo) (plugin.Supervisor, error)
+
+type ActivePlugin struct {
+	BundleInfo *model.BundleInfo
+	Supervisor plugin.Supervisor
+}
 
 // Environment represents an environment that plugins are discovered and launched in.
 type Environment struct {
 	searchPath         string
+	webappPath         string
 	apiProvider        APIProviderFunc
 	supervisorProvider SupervisorProviderFunc
-	activePlugins      map[string]plugin.Supervisor
+	activePlugins      map[string]ActivePlugin
+	mutex              sync.Mutex
 }
 
 type Option func(*Environment)
@@ -25,7 +35,7 @@ type Option func(*Environment)
 // Creates a new environment. At a minimum, the APIProvider and SearchPath options are required.
 func New(options ...Option) (*Environment, error) {
 	env := &Environment{
-		activePlugins: make(map[string]plugin.Supervisor),
+		activePlugins: make(map[string]ActivePlugin),
 	}
 	for _, opt := range options {
 		opt(env)
@@ -35,19 +45,45 @@ func New(options ...Option) (*Environment, error) {
 	}
 	if env.searchPath == "" {
 		return nil, fmt.Errorf("a search path must be provided")
-	} else if env.apiProvider == nil {
-		return nil, fmt.Errorf("an api provider must be provided")
 	}
 	return env, nil
 }
 
+// Returns the configured webapp path.
+func (env *Environment) WebappPath() string {
+	return env.webappPath
+}
+
+// Returns the configured search path.
+func (env *Environment) SearchPath() string {
+	return env.searchPath
+}
+
 // Returns a list of all plugins found within the environment.
-func (env *Environment) Plugins() ([]*plugin.BundleInfo, error) {
+func (env *Environment) Plugins() ([]*model.BundleInfo, error) {
+	env.mutex.Lock()
+	defer env.mutex.Unlock()
 	return ScanSearchPath(env.searchPath)
 }
 
+// Returns a list of all currently active plugins within the environment.
+func (env *Environment) ActivePlugins() ([]*model.BundleInfo, error) {
+	env.mutex.Lock()
+	defer env.mutex.Unlock()
+
+	activePlugins := []*model.BundleInfo{}
+	for _, p := range env.activePlugins {
+		activePlugins = append(activePlugins, p.BundleInfo)
+	}
+
+	return activePlugins, nil
+}
+
 // Returns the ids of the currently active plugins.
 func (env *Environment) ActivePluginIds() (ids []string) {
+	env.mutex.Lock()
+	defer env.mutex.Unlock()
+
 	for id := range env.activePlugins {
 		ids = append(ids, id)
 	}
@@ -56,6 +92,9 @@ func (env *Environment) ActivePluginIds() (ids []string) {
 
 // Activates the plugin with the given id.
 func (env *Environment) ActivatePlugin(id string) error {
+	env.mutex.Lock()
+	defer env.mutex.Unlock()
+
 	if _, ok := env.activePlugins[id]; ok {
 		return fmt.Errorf("plugin already active: %v", id)
 	}
@@ -63,46 +102,91 @@ func (env *Environment) ActivatePlugin(id string) error {
 	if err != nil {
 		return err
 	}
-	var plugin *plugin.BundleInfo
+	var bundle *model.BundleInfo
 	for _, p := range plugins {
 		if p.Manifest != nil && p.Manifest.Id == id {
-			if plugin != nil {
+			if bundle != nil {
 				return fmt.Errorf("multiple plugins found: %v", id)
 			}
-			plugin = p
+			bundle = p
 		}
 	}
-	if plugin == nil {
+	if bundle == nil {
 		return fmt.Errorf("plugin not found: %v", id)
 	}
-	supervisor, err := env.supervisorProvider(plugin)
-	if err != nil {
-		return errors.Wrapf(err, "unable to create supervisor for plugin: %v", id)
-	}
-	api, err := env.apiProvider(plugin.Manifest)
-	if err != nil {
-		return errors.Wrapf(err, "unable to get api for plugin: %v", id)
-	}
-	if err := supervisor.Start(); err != nil {
-		return errors.Wrapf(err, "unable to start plugin: %v", id)
+
+	activePlugin := ActivePlugin{BundleInfo: bundle}
+
+	var supervisor plugin.Supervisor
+
+	if bundle.Manifest.Backend != nil {
+		if env.apiProvider == nil {
+			return fmt.Errorf("env missing api provider, cannot activate plugin: %v", id)
+		}
+
+		supervisor, err = env.supervisorProvider(bundle)
+		if err != nil {
+			return errors.Wrapf(err, "unable to create supervisor for plugin: %v", id)
+		}
+		api, err := env.apiProvider(bundle.Manifest)
+		if err != nil {
+			return errors.Wrapf(err, "unable to get api for plugin: %v", id)
+		}
+		if err := supervisor.Start(); err != nil {
+			return errors.Wrapf(err, "unable to start plugin: %v", id)
+		}
+		if err := supervisor.Hooks().OnActivate(api); err != nil {
+			supervisor.Stop()
+			return errors.Wrapf(err, "unable to activate plugin: %v", id)
+		}
+
+		activePlugin.Supervisor = supervisor
 	}
-	if err := supervisor.Hooks().OnActivate(api); err != nil {
-		supervisor.Stop()
-		return errors.Wrapf(err, "unable to activate plugin: %v", id)
+
+	if bundle.Manifest.Webapp != nil {
+		if env.webappPath == "" {
+			if supervisor != nil {
+				supervisor.Stop()
+			}
+			return fmt.Errorf("env missing webapp path, cannot activate plugin: %v", id)
+		}
+
+		webappBundle, err := ioutil.ReadFile(fmt.Sprintf("%s/%s/webapp/%s_bundle.js", env.searchPath, id, id))
+		if err != nil {
+			if supervisor != nil {
+				supervisor.Stop()
+			}
+			return errors.Wrapf(err, "unable to read webapp bundle: %v", id)
+		}
+
+		err = ioutil.WriteFile(fmt.Sprintf("%s/%s_bundle.js", env.webappPath, id), webappBundle, 0644)
+		if err != nil {
+			if supervisor != nil {
+				supervisor.Stop()
+			}
+			return errors.Wrapf(err, "unable to write webapp bundle: %v", id)
+		}
 	}
-	env.activePlugins[id] = supervisor
+
+	env.activePlugins[id] = activePlugin
 	return nil
 }
 
 // Deactivates the plugin with the given id.
 func (env *Environment) DeactivatePlugin(id string) error {
-	if supervisor, ok := env.activePlugins[id]; !ok {
+	env.mutex.Lock()
+	defer env.mutex.Unlock()
+
+	if activePlugin, ok := env.activePlugins[id]; !ok {
 		return fmt.Errorf("plugin not active: %v", id)
 	} else {
 		delete(env.activePlugins, id)
-		err := supervisor.Hooks().OnDeactivate()
-		if serr := supervisor.Stop(); err == nil {
-			err = serr
+		var err error
+		if activePlugin.Supervisor != nil {
+			err = activePlugin.Supervisor.Hooks().OnDeactivate()
+			if serr := activePlugin.Supervisor.Stop(); err == nil {
+				err = serr
+			}
 		}
 		return err
 	}
@@ -110,14 +194,19 @@ func (env *Environment) DeactivatePlugin(id string) error {
 
 // Deactivates all plugins and gracefully shuts down the environment.
 func (env *Environment) Shutdown() (errs []error) {
-	for _, supervisor := range env.activePlugins {
-		if err := supervisor.Hooks().OnDeactivate(); err != nil {
-			errs = append(errs, err)
-		}
-		if err := supervisor.Stop(); err != nil {
-			errs = append(errs, err)
+	env.mutex.Lock()
+	defer env.mutex.Unlock()
+
+	for _, activePlugin := range env.activePlugins {
+		if activePlugin.Supervisor != nil {
+			if err := activePlugin.Supervisor.Hooks().OnDeactivate(); err != nil {
+				errs = append(errs, err)
+			}
+			if err := activePlugin.Supervisor.Stop(); err != nil {
+				errs = append(errs, err)
+			}
 		}
 	}
-	env.activePlugins = make(map[string]plugin.Supervisor)
+	env.activePlugins = make(map[string]ActivePlugin)
 	return
 }
diff --git a/plugin/pluginenv/environment_test.go b/plugin/pluginenv/environment_test.go
index d933c8696..82086b9b6 100644
--- a/plugin/pluginenv/environment_test.go
+++ b/plugin/pluginenv/environment_test.go
@@ -11,6 +11,7 @@ import (
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/require"
 
+	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/plugin"
 	"github.com/mattermost/platform/plugin/plugintest"
 )
@@ -19,7 +20,7 @@ type MockProvider struct {
 	mock.Mock
 }
 
-func (m *MockProvider) API(manifest *plugin.Manifest) (plugin.API, error) {
+func (m *MockProvider) API(manifest *model.Manifest) (plugin.API, error) {
 	ret := m.Called()
 	if ret.Get(0) == nil {
 		return nil, ret.Error(1)
@@ -27,7 +28,7 @@ func (m *MockProvider) API(manifest *plugin.Manifest) (plugin.API, error) {
 	return ret.Get(0).(plugin.API), ret.Error(1)
 }
 
-func (m *MockProvider) Supervisor(bundle *plugin.BundleInfo) (plugin.Supervisor, error) {
+func (m *MockProvider) Supervisor(bundle *model.BundleInfo) (plugin.Supervisor, error) {
 	ret := m.Called()
 	if ret.Get(0) == nil {
 		return nil, ret.Error(1)
@@ -90,19 +91,13 @@ func TestNew_MissingOptions(t *testing.T) {
 	)
 	assert.Nil(t, env)
 	assert.Error(t, err)
-
-	env, err = New(
-		SearchPath(dir),
-	)
-	assert.Nil(t, env)
-	assert.Error(t, err)
 }
 
 func TestEnvironment(t *testing.T) {
 	dir := initTmpDir(t, map[string]string{
 		".foo/plugin.json": `{"id": "foo"}`,
 		"foo/bar":          "asdf",
-		"foo/plugin.json":  `{"id": "foo"}`,
+		"foo/plugin.json":  `{"id": "foo", "backend": {}}`,
 		"bar/zxc":          "qwer",
 		"baz/plugin.yaml":  "id: baz",
 		"bad/plugin.json":  "asd",
@@ -110,11 +105,14 @@ func TestEnvironment(t *testing.T) {
 	})
 	defer os.RemoveAll(dir)
 
+	webappDir := "notarealdirectory"
+
 	var provider MockProvider
 	defer provider.AssertExpectations(t)
 
 	env, err := New(
 		SearchPath(dir),
+		WebappPath(webappDir),
 		APIProvider(provider.API),
 		SupervisorProvider(provider.Supervisor),
 	)
@@ -125,6 +123,10 @@ func TestEnvironment(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Len(t, plugins, 3)
 
+	activePlugins, err := env.ActivePlugins()
+	assert.NoError(t, err)
+	assert.Len(t, activePlugins, 0)
+
 	assert.Error(t, env.ActivatePlugin("x"))
 
 	var api struct{ plugin.API }
@@ -144,6 +146,9 @@ func TestEnvironment(t *testing.T) {
 
 	assert.NoError(t, env.ActivatePlugin("foo"))
 	assert.Equal(t, env.ActivePluginIds(), []string{"foo"})
+	activePlugins, err = env.ActivePlugins()
+	assert.NoError(t, err)
+	assert.Len(t, activePlugins, 1)
 	assert.Error(t, env.ActivatePlugin("foo"))
 
 	hooks.On("OnDeactivate").Return(nil)
@@ -152,6 +157,10 @@ func TestEnvironment(t *testing.T) {
 
 	assert.NoError(t, env.ActivatePlugin("foo"))
 	assert.Equal(t, env.ActivePluginIds(), []string{"foo"})
+
+	assert.Equal(t, env.SearchPath(), dir)
+	assert.Equal(t, env.WebappPath(), webappDir)
+
 	assert.Empty(t, env.Shutdown())
 }
 
@@ -195,7 +204,7 @@ func TestEnvironment_BadSearchPathError(t *testing.T) {
 
 func TestEnvironment_ActivatePluginErrors(t *testing.T) {
 	dir := initTmpDir(t, map[string]string{
-		"foo/plugin.json": `{"id": "foo"}`,
+		"foo/plugin.json": `{"id": "foo", "backend": {}}`,
 	})
 	defer os.RemoveAll(dir)
 
@@ -254,7 +263,7 @@ func TestEnvironment_ActivatePluginErrors(t *testing.T) {
 
 func TestEnvironment_ShutdownError(t *testing.T) {
 	dir := initTmpDir(t, map[string]string{
-		"foo/plugin.json": `{"id": "foo"}`,
+		"foo/plugin.json": `{"id": "foo", "backend": {}}`,
 	})
 	defer os.RemoveAll(dir)
 
diff --git a/plugin/pluginenv/options.go b/plugin/pluginenv/options.go
index 3f83228fb..e5ef9678d 100644
--- a/plugin/pluginenv/options.go
+++ b/plugin/pluginenv/options.go
@@ -3,6 +3,7 @@ package pluginenv
 import (
 	"fmt"
 
+	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/plugin"
 	"github.com/mattermost/platform/plugin/rpcplugin"
 )
@@ -29,14 +30,21 @@ func SearchPath(path string) Option {
 	}
 }
 
+// WebappPath specifies the static directory serving the webapp.
+func WebappPath(path string) Option {
+	return func(env *Environment) {
+		env.webappPath = path
+	}
+}
+
 // DefaultSupervisorProvider chooses a supervisor based on the plugin's manifest contents. E.g. if
 // the manifest specifies a backend executable, it will be given an rpcplugin.Supervisor.
-func DefaultSupervisorProvider(bundle *plugin.BundleInfo) (plugin.Supervisor, error) {
+func DefaultSupervisorProvider(bundle *model.BundleInfo) (plugin.Supervisor, error) {
 	if bundle.Manifest == nil {
 		return nil, fmt.Errorf("a manifest is required")
 	}
 	if bundle.Manifest.Backend == nil {
-		return nil, fmt.Errorf("invalid manifest: at this time, only backend plugins are supported")
+		return nil, fmt.Errorf("invalid manifest: missing backend plugin")
 	}
 	return rpcplugin.SupervisorProvider(bundle)
 }
diff --git a/plugin/pluginenv/options_test.go b/plugin/pluginenv/options_test.go
index 4f8d411bd..073d1861e 100644
--- a/plugin/pluginenv/options_test.go
+++ b/plugin/pluginenv/options_test.go
@@ -6,22 +6,22 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/mattermost/platform/plugin"
+	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/plugin/rpcplugin"
 )
 
 func TestDefaultSupervisorProvider(t *testing.T) {
-	_, err := DefaultSupervisorProvider(&plugin.BundleInfo{})
+	_, err := DefaultSupervisorProvider(&model.BundleInfo{})
 	assert.Error(t, err)
 
-	_, err = DefaultSupervisorProvider(&plugin.BundleInfo{
-		Manifest: &plugin.Manifest{},
+	_, err = DefaultSupervisorProvider(&model.BundleInfo{
+		Manifest: &model.Manifest{},
 	})
 	assert.Error(t, err)
 
-	supervisor, err := DefaultSupervisorProvider(&plugin.BundleInfo{
-		Manifest: &plugin.Manifest{
-			Backend: &plugin.ManifestBackend{
+	supervisor, err := DefaultSupervisorProvider(&model.BundleInfo{
+		Manifest: &model.Manifest{
+			Backend: &model.ManifestBackend{
 				Executable: "foo",
 			},
 		},
diff --git a/plugin/pluginenv/search_path.go b/plugin/pluginenv/search_path.go
index daebdb0d3..b50c7019c 100644
--- a/plugin/pluginenv/search_path.go
+++ b/plugin/pluginenv/search_path.go
@@ -4,7 +4,7 @@ import (
 	"io/ioutil"
 	"path/filepath"
 
-	"github.com/mattermost/platform/plugin"
+	"github.com/mattermost/platform/model"
 )
 
 // Performs a full scan of the given path.
@@ -14,17 +14,17 @@ import (
 // parsed).
 //
 // Plugins are found non-recursively and paths beginning with a dot are always ignored.
-func ScanSearchPath(path string) ([]*plugin.BundleInfo, error) {
+func ScanSearchPath(path string) ([]*model.BundleInfo, error) {
 	files, err := ioutil.ReadDir(path)
 	if err != nil {
 		return nil, err
 	}
-	var ret []*plugin.BundleInfo
+	var ret []*model.BundleInfo
 	for _, file := range files {
 		if !file.IsDir() || file.Name()[0] == '.' {
 			continue
 		}
-		if info := plugin.BundleInfoForPath(filepath.Join(path, file.Name())); info.ManifestPath != "" {
+		if info := model.BundleInfoForPath(filepath.Join(path, file.Name())); info.ManifestPath != "" {
 			ret = append(ret, info)
 		}
 	}
diff --git a/plugin/pluginenv/search_path_test.go b/plugin/pluginenv/search_path_test.go
index d9a18cf56..f8243e5e4 100644
--- a/plugin/pluginenv/search_path_test.go
+++ b/plugin/pluginenv/search_path_test.go
@@ -9,7 +9,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/mattermost/platform/plugin"
+	"github.com/mattermost/platform/model"
 )
 
 func TestScanSearchPath(t *testing.T) {
@@ -27,17 +27,17 @@ func TestScanSearchPath(t *testing.T) {
 	plugins, err := ScanSearchPath(dir)
 	require.NoError(t, err)
 	assert.Len(t, plugins, 3)
-	assert.Contains(t, plugins, &plugin.BundleInfo{
+	assert.Contains(t, plugins, &model.BundleInfo{
 		Path:         filepath.Join(dir, "foo"),
 		ManifestPath: filepath.Join(dir, "foo", "plugin.json"),
-		Manifest: &plugin.Manifest{
+		Manifest: &model.Manifest{
 			Id: "foo",
 		},
 	})
-	assert.Contains(t, plugins, &plugin.BundleInfo{
+	assert.Contains(t, plugins, &model.BundleInfo{
 		Path:         filepath.Join(dir, "baz"),
 		ManifestPath: filepath.Join(dir, "baz", "plugin.yaml"),
-		Manifest: &plugin.Manifest{
+		Manifest: &model.Manifest{
 			Id: "baz",
 		},
 	})