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/api4/cluster.go

@@ -0,0 +1,35 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package api4
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+)
+
+func (api *API) InitCluster() {
+	api.BaseRoutes.Cluster.Handle("/status", api.APISessionRequired(getClusterStatus)).Methods("GET")
+}
+
+func getClusterStatus(c *Context, w http.ResponseWriter, r *http.Request) {
+	if !c.App.SessionHasPermissionTo(*c.AppContext.Session(), model.PermissionSysconsoleReadEnvironmentHighAvailability) {
+		c.SetPermissionError(model.PermissionSysconsoleReadEnvironmentHighAvailability)
+		return
+	}
+
+	if *c.App.Config().ExperimentalSettings.RestrictSystemAdmin {
+		c.Err = model.NewAppError("getClusterStatus", "api.restricted_system_admin", nil, "", http.StatusForbidden)
+		return
+	}
+
+	infos := c.App.GetClusterStatus()
+	js, err := json.Marshal(infos)
+	if err != nil {
+		c.Err = model.NewAppError("getClusterStatus", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(err)
+		return
+	}
+	w.Write(js)
+}