fix: log and rethrow whenever are listFunctions fail

these calls aren't wrapped and end up as unhandled rejections, with little to no logging for their source and cause.
this commit wraps these calls with some logs so we can at least explain future unhandled rejections coming from this area.

Author: Shesekino

src/supervisor/watchers/handlers/index.ts

@@ -95,8 +95,17 @@ export function setupInformer(namespace: string, workloadKind: WorkloadKind) {
   const workloadMetadata = workloadWatchMetadata[workloadKind];
   const namespacedEndpoint = workloadMetadata.endpoint.replace('{namespace}', namespace);
 
-  const informer = makeInformer<KubernetesObject>(kubeConfig, namespacedEndpoint,
-    workloadMetadata.listFactory(namespace));
+  const listMethod = workloadMetadata.listFactory(namespace);
+  const loggedListMethod = async () => {
+    try {
+      return await listMethod();
+    } catch (err) {
+      logger.error({err, namespace, workloadKind}, 'error while listing entities on namespace');
+      throw err;
+    }
+  };
+
+  const informer = makeInformer<KubernetesObject>(kubeConfig, namespacedEndpoint, loggedListMethod);
 
   for (const informerVerb of Object.keys(workloadMetadata.handlers)) {
     informer.on(informerVerb, async (watchedWorkload) => {

src/supervisor/watchers/index.ts

@@ -1,5 +1,6 @@
 import { makeInformer, ADD } from '@kubernetes/client-node';
 import { V1Namespace } from '@kubernetes/client-node';
+
 import config = require('../../common/config');
 import logger = require('../../common/logger');
 import { WorkloadKind } from '../types';
@@ -51,7 +52,18 @@ export function isKubernetesInternalNamespace(namespace: string): boolean {
 }
 
 function setupWatchesForCluster(): void {
-  const informer = makeInformer(kubeConfig, '/api/v1/namespaces', () => k8sApi.coreClient.listNamespace());
+  const informer = makeInformer(
+    kubeConfig,
+    '/api/v1/namespaces',
+    async () => {
+      try {
+        return await k8sApi.coreClient.listNamespace();
+      } catch (err) {
+        logger.error({err}, 'error while listing namespaces');
+        throw err;
+      }
+    },
+  );
 
   informer.on(ADD, (namespace: V1Namespace) => {
     try {