Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/app/searchengine.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package app
+
+import (
+	"net/http"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/platform/services/searchengine"
+)
+
+func (a *App) TestElasticsearch(cfg *model.Config) *model.AppError {
+	if *cfg.ElasticsearchSettings.Password == model.FakeSetting {
+		if *cfg.ElasticsearchSettings.ConnectionURL == *a.Config().ElasticsearchSettings.ConnectionURL && *cfg.ElasticsearchSettings.Username == *a.Config().ElasticsearchSettings.Username {
+			*cfg.ElasticsearchSettings.Password = *a.Config().ElasticsearchSettings.Password
+		} else {
+			return model.NewAppError("TestElasticsearch", "ent.elasticsearch.test_config.reenter_password", nil, "", http.StatusBadRequest)
+		}
+	}
+
+	seI := a.SearchEngine().ElasticsearchEngine
+	if seI == nil {
+		err := model.NewAppError("TestElasticsearch", "ent.elasticsearch.test_config.license.error", nil, "", http.StatusNotImplemented)
+		return err
+	}
+	if err := seI.TestConfig(cfg); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *App) SetSearchEngine(se *searchengine.Broker) {
+	a.ch.srv.platform.SearchEngine = se
+}
+
+func (a *App) PurgeElasticsearchIndexes() *model.AppError {
+	engine := a.SearchEngine().ElasticsearchEngine
+	if engine == nil {
+		err := model.NewAppError("PurgeElasticsearchIndexes", "ent.elasticsearch.test_config.license.error", nil, "", http.StatusNotImplemented)
+		return err
+	}
+
+	if err := engine.PurgeIndexes(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *App) PurgeBleveIndexes() *model.AppError {
+	engine := a.SearchEngine().BleveEngine
+	if engine == nil {
+		err := model.NewAppError("PurgeBleveIndexes", "searchengine.bleve.disabled.error", nil, "", http.StatusNotImplemented)
+		return err
+	}
+	if err := engine.PurgeIndexes(); err != nil {
+		return err
+	}
+	return nil
+}