MM-49984: Displaying active search backend in system console (#22721)

This will be shown in the system console to let users know
which search backend is active.

Implemented via adding an extra param in the ping response.

https://mattermost.atlassian.net/browse/MM-49984

```release-note
The database section in the system console now has an additional
read-only section which shows the active search backend in use.

This can be helpful to confirm which is the currently active
search engine when there are multiple of them configured.
```
---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/api4/system.go

@@ -190,6 +190,8 @@ func getSystemPing(c *Context, w http.ResponseWriter, r *http.Request) {
 		s["CanReceiveNotifications"] = c.App.SendTestPushNotification(deviceID)
 	}
 
+	s["ActiveSearchBackend"] = c.App.ActiveSearchBackend()
+
 	if s[model.STATUS] != model.StatusOk {
 		w.WriteHeader(http.StatusInternalServerError)
 	}

server/channels/app/app_iface.go

@@ -400,6 +400,7 @@ type AppIface interface {
 	VerifyPlugin(plugin, signature io.ReadSeeker) *model.AppError
 	AccountMigration() einterfaces.AccountMigrationInterface
 	ActivateMfa(userID, token string) *model.AppError
+	ActiveSearchBackend() string
 	AddChannelsToRetentionPolicy(policyID string, channelIDs []string) *model.AppError
 	AddConfigListener(listener func(*model.Config, *model.Config)) string
 	AddDirectChannels(c request.CTX, teamID string, user *model.User) *model.AppError

server/channels/app/opentracing/opentracing_layer.go

@@ -89,6 +89,23 @@ func (a *OpenTracingAppLayer) ActivateMfa(userID string, token string) *model.Ap
 	return resultVar0
 }
 
+func (a *OpenTracingAppLayer) ActiveSearchBackend() string {
+	origCtx := a.ctx
+	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.ActiveSearchBackend")
+
+	a.ctx = newCtx
+	a.app.Srv().Store().SetContext(newCtx)
+	defer func() {
+		a.app.Srv().Store().SetContext(origCtx)
+		a.ctx = origCtx
+	}()
+
+	defer span.Finish()
+	resultVar0 := a.app.ActiveSearchBackend()
+
+	return resultVar0
+}
+
 func (a *OpenTracingAppLayer) AddChannelMember(c request.CTX, userID string, channel *model.Channel, opts app.ChannelMemberOpts) (*model.ChannelMember, *model.AppError) {
 	origCtx := a.ctx
 	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.AddChannelMember")

server/channels/app/searchengine.go

@@ -60,3 +60,7 @@ func (a *App) PurgeBleveIndexes() *model.AppError {
 	}
 	return nil
 }
+
+func (a *App) ActiveSearchBackend() string {
+	return a.ch.srv.platform.SearchEngine.ActiveEngine()
+}

server/i18n/en.json

@@ -7795,6 +7795,10 @@
     "id": "ent.elasticsearch.indexer.index_batch.nothing_left_to_index.error",
     "translation": "Trying to index a new batch when all the entities are completed"
   },
+  {
+    "id": "ent.elasticsearch.max_version.app_error",
+    "translation": "Elasticsearch version {{.Version}} is higher than max supported version of {{.MaxVersion}}"
+  },
   {
     "id": "ent.elasticsearch.not_started.error",
     "translation": "Elasticsearch is not started"
@@ -7863,10 +7867,6 @@
     "id": "ent.elasticsearch.search_users.unmarshall_user_failed",
     "translation": "Failed to decode search results"
   },
-  {
-    "id": "ent.elasticsearch.start.already_started.app_error",
-    "translation": "Elasticsearch is already started."
-  },
   {
     "id": "ent.elasticsearch.start.create_bulk_processor_failed.app_error",
     "translation": "Failed to create Elasticsearch bulk processor."

server/platform/services/searchengine/searchengine.go

@@ -45,8 +45,19 @@ func (seb *Broker) GetActiveEngines() []SearchEngineInterface {
 	if seb.ElasticsearchEngine != nil && seb.ElasticsearchEngine.IsActive() {
 		engines = append(engines, seb.ElasticsearchEngine)
 	}
-	if seb.BleveEngine != nil && seb.BleveEngine.IsActive() {
+	if seb.BleveEngine != nil && seb.BleveEngine.IsActive() && seb.BleveEngine.IsIndexingEnabled() {
 		engines = append(engines, seb.BleveEngine)
 	}
 	return engines
 }
+
+func (seb *Broker) ActiveEngine() string {
+	activeEngines := seb.GetActiveEngines()
+	if len(activeEngines) > 0 {
+		return activeEngines[0].GetName()
+	}
+	if *seb.cfg.SqlSettings.DisableDatabaseSearch {
+		return "none"
+	}
+	return "database"
+}

server/platform/services/searchengine/searchengine_test.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package searchengine
+
+import (
+	"testing"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/platform/services/searchengine/mocks"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestActiveEngine(t *testing.T) {
+	cfg := &model.Config{}
+	cfg.SetDefaults()
+
+	b := NewBroker(cfg)
+
+	esMock := &mocks.SearchEngineInterface{}
+	esMock.On("IsActive").Return(true)
+	esMock.On("GetName").Return("elasticsearch")
+
+	bleveMock := &mocks.SearchEngineInterface{}
+	bleveMock.On("IsActive").Return(true)
+	bleveMock.On("IsIndexingEnabled").Return(true)
+	bleveMock.On("GetName").Return("bleve")
+
+	assert.Equal(t, "database", b.ActiveEngine())
+
+	b.ElasticsearchEngine = esMock
+	assert.Equal(t, "elasticsearch", b.ActiveEngine())
+
+	b.ElasticsearchEngine = nil
+	b.BleveEngine = bleveMock
+	assert.Equal(t, "bleve", b.ActiveEngine())
+
+	b.BleveEngine = nil
+	*b.cfg.SqlSettings.DisableDatabaseSearch = true
+
+	assert.Equal(t, "none", b.ActiveEngine())
+}

webapp/channels/src/components/admin_console/__snapshots__/database_settings.test.jsx.snap

@@ -353,6 +353,36 @@ exports[`components/DatabaseSettings should match snapshot 1`] = `
           </div>
         </div>
       </div>
+      <div
+        className="form-group"
+      >
+        <label
+          className="control-label col-sm-4"
+        >
+          <MemoizedFormattedMessage
+            defaultMessage="Active Search Backend:"
+            id="admin.database.search_backend.title"
+          />
+        </label>
+        <div
+          className="col-sm-8"
+        >
+          <input
+            className="form-control"
+            disabled={true}
+            type="text"
+            value=""
+          />
+          <div
+            className="help-text"
+          >
+            <MemoizedFormattedMessage
+              defaultMessage="Shows the currently active backend used for search. Values can be none, database, elasticsearch, bleve etc."
+              id="admin.database.search_backend.help_text"
+            />
+          </div>
+        </div>
+      </div>
     </SettingsGroup>
     <div
       className="admin-console-save"

webapp/channels/src/components/admin_console/database_settings.jsx

@@ -4,7 +4,7 @@
 import React from 'react';
 import {FormattedMessage} from 'react-intl';
 
-import {recycleDatabaseConnection} from 'actions/admin_actions.jsx';
+import {recycleDatabaseConnection, ping} from 'actions/admin_actions';
 import * as Utils from 'utils/utils';
 import {t} from 'utils/i18n';
 
@@ -19,6 +19,15 @@ import TextSetting from './text_setting';
 import MigrationsTable from './database';
 
 export default class DatabaseSettings extends AdminSettings {
+    constructor(props) {
+        super(props);
+
+        this.state = {
+            ...this.state,
+            searchBackend: '',
+        };
+    }
+
     getConfigFromState = (config) => {
         // driverName and dataSource are read-only from the UI
 
@@ -34,6 +43,17 @@ export default class DatabaseSettings extends AdminSettings {
         return config;
     };
 
+    componentDidMount() {
+        this.getSearchBackend().then((searchBackend) => {
+            this.setState({searchBackend});
+        });
+    }
+
+    async getSearchBackend() {
+        const res = await ping()();
+        return res.ActiveSearchBackend;
+    }
+
     getStateFromConfig(config) {
         return {
             driverName: config.SqlSettings.DriverName,
@@ -368,6 +388,30 @@ export default class DatabaseSettings extends AdminSettings {
                         </div>
                     </div>
                 </div>
+                <div className='form-group'>
+                    <label
+                        className='control-label col-sm-4'
+                    >
+                        <FormattedMessage
+                            id='admin.database.search_backend.title'
+                            defaultMessage='Active Search Backend:'
+                        />
+                    </label>
+                    <div className='col-sm-8'>
+                        <input
+                            type='text'
+                            className='form-control'
+                            value={this.state.searchBackend}
+                            disabled={true}
+                        />
+                        <div className='help-text'>
+                            <FormattedMessage
+                                id='admin.database.search_backend.help_text'
+                                defaultMessage='Shows the currently active backend used for search. Values can be none, database, elasticsearch, bleve etc.'
+                            />
+                        </div>
+                    </div>
+                </div>
             </SettingsGroup>
         );
     };

webapp/channels/src/components/admin_console/database_settings.test.jsx

@@ -7,8 +7,14 @@ import {shallow} from 'enzyme';
 import DatabaseSettings from 'components/admin_console/database_settings.jsx';
 
 jest.mock('actions/admin_actions.jsx', () => {
+    const pingFn = () => {
+        return jest.fn(() => {
+            return {ActiveSearchBackend: 'none'};
+        });
+    };
     return {
         recycleDatabaseConnection: jest.fn(),
+        ping: pingFn,
     };
 });
 

webapp/channels/src/i18n/en.json

@@ -741,6 +741,8 @@
   "admin.database.migrations_table.name": "Name",
   "admin.database.migrations_table.title": "Applied Schema Migrations",
   "admin.database.migrations_table.version": "Version",
+  "admin.database.search_backend.help_text": "Shows the currently active backend used for search. Values can be none, database, elasticsearch, bleve etc.",
+  "admin.database.search_backend.title": "Active Search Backend",
   "admin.database.title": "Database",
   "admin.developer.title": "Developer Settings",
   "admin.elasticsearch.bulkIndexingTitle": "Bulk Indexing:",

webapp/platform/client/src/client4.ts

@@ -2439,6 +2439,7 @@ export default class Client4 {
     ping = () => {
         return this.doFetch<{
             status: string;
+            ActiveSearchBackend: string;
         }>(
             `${this.getBaseRoute()}/system/ping?time=${Date.now()}`,
             {method: 'get'},