feat(k8s/container): realtime metrics (#4416)

* feat(k8s/container): metrics layout

* feat(k8s/container): memory graph

* feat(k8s/container): cpu usage percent

* feat(k8s/metrics): metrics api validation to enable metrics server

* feat(k8s/pods): update error metrics view

* feat(k8s/container): improve stopRepeater function

* feat(k8s/pods): display empty view instead of empty graphs

* feat(k8s/pods): fix CPU usage

* feat(k8s/configure): fix the metrics server test

* feat(k8s/pod): fix cpu issue

* feat(k8s/pod): fix toaster for non register pods in metrics server

* feat(k8s/service): remove options before 30 secondes for refresh rate

* feat(k8s/pod): fix default value for the refresh rate

* feat(k8s/pod): fix rebase

app/kubernetes/metrics/metrics.js

@@ -0,0 +1,53 @@
+import angular from 'angular';
+import PortainerError from 'Portainer/error';
+import { KubernetesCommonParams } from 'Kubernetes/models/common/params';
+
+class KubernetesMetricsService {
+  /* @ngInject */
+  constructor($async, KubernetesMetrics) {
+    this.$async = $async;
+    this.KubernetesMetrics = KubernetesMetrics;
+
+    this.capabilitiesAsync = this.capabilitiesAsync.bind(this);
+    this.getPodAsync = this.getPodAsync.bind(this);
+  }
+
+  /**
+   * GET
+   */
+  async capabilitiesAsync(endpointID) {
+    try {
+      await this.KubernetesMetrics().capabilities({ endpointId: endpointID }).$promise;
+    } catch (err) {
+      throw new PortainerError('Unable to retrieve metrics', err);
+    }
+  }
+
+  capabilities(endpointID) {
+    return this.$async(this.capabilitiesAsync, endpointID);
+  }
+
+  /**
+   * Stats
+   *
+   * @param {string} namespace
+   * @param {string} podName
+   */
+  async getPodAsync(namespace, podName) {
+    try {
+      const params = new KubernetesCommonParams();
+      params.id = podName;
+      const data = await this.KubernetesMetrics(namespace).getPod(params).$promise;
+      return data;
+    } catch (err) {
+      throw new PortainerError('Unable to retrieve pod stats', err);
+    }
+  }
+
+  getPod(namespace, podName) {
+    return this.$async(this.getPodAsync, namespace, podName);
+  }
+}
+
+export default KubernetesMetricsService;
+angular.module('portainer.kubernetes').service('KubernetesMetricsService', KubernetesMetricsService);

app/kubernetes/metrics/rest.js

@@ -0,0 +1,27 @@
+angular.module('portainer.kubernetes').factory('KubernetesMetrics', [
+  '$resource',
+  'API_ENDPOINT_ENDPOINTS',
+  'EndpointProvider',
+  function KubernetesMetrics($resource, API_ENDPOINT_ENDPOINTS, EndpointProvider) {
+    'use strict';
+    return function (namespace) {
+      const url = API_ENDPOINT_ENDPOINTS + '/:endpointId/kubernetes/apis/metrics.k8s.io/v1beta1';
+      const podUrl = `${url}${namespace ? '/namespaces/:namespace' : ''}/pods/:id`;
+
+      return $resource(
+        url,
+        {
+          endpointId: EndpointProvider.endpointID,
+          namespace: namespace,
+        },
+        {
+          capabilities: { method: 'GET' },
+          getPod: {
+            method: 'GET',
+            url: podUrl,
+          },
+        }
+      );
+    };
+  },
+]);