fix(dashboard): use faster proxy request [EE-5160] (#8694)

Co-authored-by: testa113 <testa113>

app/kubernetes/__module.js

@@ -1,4 +1,5 @@
 import { EnvironmentStatus } from '@/react/portainer/environments/types';
+import { getSelfSubjectAccessReview } from '@/react/kubernetes/namespaces/service';
 
 import { PortainerEndpointTypes } from 'Portainer/models/endpoint/models';
 
@@ -47,7 +48,13 @@ angular.module('portainer.kubernetes', ['portainer.app', registriesModule, custo
               throw new Error('Unable to contact Edge agent, please ensure that the agent is properly running on the remote environment.');
             }
 
-            await KubernetesNamespaceService.get();
+            // use selfsubject access review to check if we can connect to the kubernetes environment
+            // because it's gets a fast response, and is accessible to all users
+            try {
+              await getSelfSubjectAccessReview(endpoint.Id, 'default');
+            } catch (e) {
+              throw new Error('Environment is unreachable.');
+            }
           } catch (e) {
             let params = {};
 

app/react/kubernetes/namespaces/service.ts

@@ -3,6 +3,7 @@ import { EnvironmentId } from '@/react/portainer/environments/types';
 
 import { Namespaces, SelfSubjectAccessReviewResponse } from './types';
 
+// getNamespace is used to retrieve a namespace using the Portainer backend
 export async function getNamespace(
   environmentId: EnvironmentId,
   namespace: string
@@ -17,6 +18,7 @@ export async function getNamespace(
   }
 }
 
+// getNamespaces is used to retrieve namespaces using the Portainer backend with caching
 export async function getNamespaces(environmentId: EnvironmentId) {
   try {
     const { data: namespaces } = await axios.get<Namespaces>(