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, 260 insertions, 0 deletions

diff --git a/api4/api.go b/api4/api.go
index 8ed94c193..3a4f2c412 100644
--- a/api4/api.go
+++ b/api4/api.go
@@ -53,6 +53,9 @@ type Routes struct {
 	Files *mux.Router // 'api/v4/files'
 	File  *mux.Router // 'api/v4/files/{file_id:[A-Za-z0-9]+}'
 
+	Plugins *mux.Router // 'api/v4/plugins'
+	Plugin  *mux.Router // 'api/v4/plugins/{plugin_id:[A-Za-z0-9_-]+}'
+
 	PublicFile *mux.Router // 'files/{file_id:[A-Za-z0-9]+}/public'
 
 	Commands *mux.Router // 'api/v4/commands'
@@ -146,6 +149,9 @@ func InitApi(full bool) {
 	BaseRoutes.File = BaseRoutes.Files.PathPrefix("/{file_id:[A-Za-z0-9]+}").Subrouter()
 	BaseRoutes.PublicFile = BaseRoutes.Root.PathPrefix("/files/{file_id:[A-Za-z0-9]+}/public").Subrouter()
 
+	BaseRoutes.Plugins = BaseRoutes.ApiRoot.PathPrefix("/plugins").Subrouter()
+	BaseRoutes.Plugin = BaseRoutes.Plugins.PathPrefix("/{plugin_id:[A-Za-z0-9\\_\\-]+}").Subrouter()
+
 	BaseRoutes.Commands = BaseRoutes.ApiRoot.PathPrefix("/commands").Subrouter()
 	BaseRoutes.Command = BaseRoutes.Commands.PathPrefix("/{command_id:[A-Za-z0-9]+}").Subrouter()
 
@@ -205,6 +211,7 @@ func InitApi(full bool) {
 	InitReaction()
 	InitWebrtc()
 	InitOpenGraph()
+	InitPlugin()
 
 	app.Srv.Router.Handle("/api/v4/{anything:.*}", http.HandlerFunc(Handle404))
 
diff --git a/api4/context.go b/api4/context.go
index 3ea67b30c..2c0e54ea0 100644
--- a/api4/context.go
+++ b/api4/context.go
@@ -428,6 +428,18 @@ func (c *Context) RequireFileId() *Context {
 	return c
 }
 
+func (c *Context) RequirePluginId() *Context {
+	if c.Err != nil {
+		return c
+	}
+
+	if len(c.Params.PluginId) == 0 {
+		c.SetInvalidUrlParam("plugin_id")
+	}
+
+	return c
+}
+
 func (c *Context) RequireReportId() *Context {
 	if c.Err != nil {
 		return c
diff --git a/api4/params.go b/api4/params.go
index 8b1d0febe..1f0fe8e63 100644
--- a/api4/params.go
+++ b/api4/params.go
@@ -24,6 +24,7 @@ type ApiParams struct {
 	ChannelId      string
 	PostId         string
 	FileId         string
+	PluginId       string
 	CommandId      string
 	HookId         string
 	ReportId       string
@@ -78,6 +79,10 @@ func ApiParamsFromRequest(r *http.Request) *ApiParams {
 		params.FileId = val
 	}
 
+	if val, ok := props["plugin_id"]; ok {
+		params.PluginId = val
+	}
+
 	if val, ok := props["command_id"]; ok {
 		params.CommandId = val
 	}
diff --git a/api4/plugin.go b/api4/plugin.go
new file mode 100644
index 000000000..109695174
--- /dev/null
+++ b/api4/plugin.go
@@ -0,0 +1,120 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+// EXPERIMENTAL - SUBJECT TO CHANGE
+
+package api4
+
+import (
+	"net/http"
+
+	l4g "github.com/alecthomas/log4go"
+	"github.com/mattermost/platform/app"
+	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/utils"
+)
+
+const (
+	MAXIMUM_PLUGIN_FILE_SIZE = 50 * 1024 * 1024
+)
+
+func InitPlugin() {
+	l4g.Debug("EXPERIMENTAL: Initializing plugin api")
+
+	BaseRoutes.Plugins.Handle("", ApiSessionRequired(uploadPlugin)).Methods("POST")
+	BaseRoutes.Plugins.Handle("", ApiSessionRequired(getPlugins)).Methods("GET")
+	BaseRoutes.Plugin.Handle("", ApiSessionRequired(removePlugin)).Methods("DELETE")
+
+}
+
+func uploadPlugin(c *Context, w http.ResponseWriter, r *http.Request) {
+	if !*utils.Cfg.PluginSettings.Enable {
+		c.Err = model.NewAppError("uploadPlugin", "app.plugin.disabled.app_error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	if !app.SessionHasPermissionTo(c.Session, model.PERMISSION_MANAGE_SYSTEM) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+		return
+	}
+
+	if err := r.ParseMultipartForm(MAXIMUM_PLUGIN_FILE_SIZE); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	m := r.MultipartForm
+
+	pluginArray, ok := m.File["plugin"]
+	if !ok {
+		c.Err = model.NewAppError("uploadPlugin", "api.plugin.upload.no_file.app_error", nil, "", http.StatusBadRequest)
+		return
+	}
+
+	if len(pluginArray) <= 0 {
+		c.Err = model.NewAppError("uploadPlugin", "api.plugin.upload.array.app_error", nil, "", http.StatusBadRequest)
+		return
+	}
+
+	file, err := pluginArray[0].Open()
+	if err != nil {
+		c.Err = model.NewAppError("uploadPlugin", "api.plugin.upload.file.app_error", nil, "", http.StatusBadRequest)
+		return
+	}
+	defer file.Close()
+
+	manifest, unpackErr := app.UnpackAndActivatePlugin(file)
+
+	if unpackErr != nil {
+		c.Err = unpackErr
+		return
+	}
+
+	w.WriteHeader(http.StatusCreated)
+	w.Write([]byte(manifest.ToJson()))
+}
+
+func getPlugins(c *Context, w http.ResponseWriter, r *http.Request) {
+	if !*utils.Cfg.PluginSettings.Enable {
+		c.Err = model.NewAppError("getPlugins", "app.plugin.disabled.app_error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	if !app.SessionHasPermissionTo(c.Session, model.PERMISSION_MANAGE_SYSTEM) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+		return
+	}
+
+	manifests, err := app.GetActivePluginManifests()
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	w.Write([]byte(model.ManifestListToJson(manifests)))
+}
+
+func removePlugin(c *Context, w http.ResponseWriter, r *http.Request) {
+	c.RequirePluginId()
+	if c.Err != nil {
+		return
+	}
+
+	if !*utils.Cfg.PluginSettings.Enable {
+		c.Err = model.NewAppError("getPlugins", "app.plugin.disabled.app_error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	if !app.SessionHasPermissionTo(c.Session, model.PERMISSION_MANAGE_SYSTEM) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+		return
+	}
+
+	err := app.RemovePlugin(c.Params.PluginId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	ReturnStatusOK(w)
+}
diff --git a/api4/plugin_test.go b/api4/plugin_test.go
new file mode 100644
index 000000000..c1d6c987c
--- /dev/null
+++ b/api4/plugin_test.go
@@ -0,0 +1,115 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package api4
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/mattermost/platform/app"
+	"github.com/mattermost/platform/utils"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPlugin(t *testing.T) {
+	pluginDir, err := ioutil.TempDir("", "mm-plugin-test")
+	require.NoError(t, err)
+	defer func() {
+		os.RemoveAll(pluginDir)
+	}()
+	webappDir, err := ioutil.TempDir("", "mm-webapp-test")
+	require.NoError(t, err)
+	defer func() {
+		os.RemoveAll(webappDir)
+	}()
+
+	th := Setup().InitBasic().InitSystemAdmin()
+	defer TearDown()
+
+	app.StartupPlugins(pluginDir, webappDir)
+
+	enablePlugins := *utils.Cfg.PluginSettings.Enable
+	defer func() {
+		*utils.Cfg.PluginSettings.Enable = enablePlugins
+	}()
+	*utils.Cfg.PluginSettings.Enable = true
+
+	path, _ := utils.FindDir("tests")
+	file, err := os.Open(path + "/testplugin.tar.gz")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file.Close()
+
+	// Successful upload
+	manifest, resp := th.SystemAdminClient.UploadPlugin(file)
+	defer func() {
+		os.RemoveAll("plugins/testplugin")
+	}()
+	CheckNoError(t, resp)
+
+	assert.Equal(t, "testplugin", manifest.Id)
+
+	// Upload error cases
+	_, resp = th.SystemAdminClient.UploadPlugin(bytes.NewReader([]byte("badfile")))
+	CheckBadRequestStatus(t, resp)
+
+	*utils.Cfg.PluginSettings.Enable = false
+	_, resp = th.SystemAdminClient.UploadPlugin(file)
+	CheckNotImplementedStatus(t, resp)
+
+	*utils.Cfg.PluginSettings.Enable = true
+	_, resp = th.Client.UploadPlugin(file)
+	CheckForbiddenStatus(t, resp)
+
+	// Successful get
+	manifests, resp := th.SystemAdminClient.GetPlugins()
+	CheckNoError(t, resp)
+
+	found := false
+	for _, m := range manifests {
+		if m.Id == manifest.Id {
+			found = true
+		}
+	}
+
+	assert.True(t, found)
+
+	// Get error cases
+	*utils.Cfg.PluginSettings.Enable = false
+	_, resp = th.SystemAdminClient.GetPlugins()
+	CheckNotImplementedStatus(t, resp)
+
+	*utils.Cfg.PluginSettings.Enable = true
+	_, resp = th.Client.GetPlugins()
+	CheckForbiddenStatus(t, resp)
+
+	// Successful remove
+	ok, resp := th.SystemAdminClient.RemovePlugin(manifest.Id)
+	CheckNoError(t, resp)
+
+	assert.True(t, ok)
+
+	// Remove error cases
+	ok, resp = th.SystemAdminClient.RemovePlugin(manifest.Id)
+	CheckBadRequestStatus(t, resp)
+
+	assert.False(t, ok)
+
+	*utils.Cfg.PluginSettings.Enable = false
+	_, resp = th.SystemAdminClient.RemovePlugin(manifest.Id)
+	CheckNotImplementedStatus(t, resp)
+
+	*utils.Cfg.PluginSettings.Enable = true
+	_, resp = th.Client.RemovePlugin(manifest.Id)
+	CheckForbiddenStatus(t, resp)
+
+	_, resp = th.SystemAdminClient.RemovePlugin("bad.id")
+	CheckNotFoundStatus(t, resp)
+
+	app.Srv.PluginEnv = nil
+}
diff --git a/api4/system.go b/api4/system.go
index 2ad408e13..8f98afedb 100644
--- a/api4/system.go
+++ b/api4/system.go
@@ -244,6 +244,7 @@ func getClientConfig(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	respCfg["NoAccounts"] = strconv.FormatBool(app.IsFirstUserAccount())
+	respCfg["Plugins"] = app.GetPluginsForClientConfig()
 
 	w.Write([]byte(model.MapToJson(respCfg)))
 }