Update KubernetesController.java

pulsar-functions/kubernetes/src/main/java/org/apache/pulsar/functions/kubernetes/KubernetesController.java

@@ -93,6 +93,8 @@ void create(InstanceConfig instanceConfig, String userCodeFile, String pulsarSer
             instanceCodeFile = pythonInstanceFile;
         }
         final String fqn = FunctionDetailsUtils.getFullyQualifiedName(instanceConfig.getFunctionDetails());
+
+        // there are other characters that are not allowed in a pod name. see the heron code for the regex check
         if (!fqn.equals(fqn.toLowerCase())) {
             throw new RuntimeException("K8S scheduler does not allow upper case fqns.");
         }
@@ -278,14 +280,16 @@ private V1Container getContainer(List<String> executorCommand, String cpu,
                 .valueFrom(new V1EnvVarSource()
                         .fieldRef(new V1ObjectFieldSelector()
                                 .fieldPath(KubernetesConstants.POD_IP)));
-
+        */
+
+        // This env variable is needed to get the shard id
         final V1EnvVar envVarPodName = new V1EnvVar();
         envVarPodName.name(KubernetesConstants.ENV_POD_NAME)
                 .valueFrom(new V1EnvVarSource()
                         .fieldRef(new V1ObjectFieldSelector()
                                 .fieldPath(KubernetesConstants.POD_NAME)));
         container.setEnv(Arrays.asList(envVarHost, envVarPodName));
-        */
+
 
 
         // set container resources
@@ -327,4 +331,4 @@ private void mountVolumeIfPresent(V1Container container) {
         }
     }
     */
-}
+}