diff --git a/site_utils/pubsub_utils.py b/site_utils/pubsub_utils.py
index f62a31d..2f6c71d 100755
--- a/site_utils/pubsub_utils.py
+++ b/site_utils/pubsub_utils.py
@@ -27,37 +27,61 @@
 # number of retry to publish an event.
 _PUBSUB_NUM_RETRIES = 3
 
-
-def _get_pubsub_service():
-    """Gets the pubsub service api handle."""
-    if not os.path.isfile(CLOUD_SERVICE_ACCOUNT_FILE):
-        logging.error('No credential file found')
-        return None
-
-    try:
-        credentials = GoogleCredentials.from_stream(CLOUD_SERVICE_ACCOUNT_FILE)
-        if credentials.create_scoped_required():
-            credentials = credentials.create_scoped(PUBSUB_SCOPES)
-        return discovery.build(PUBSUB_SERVICE_NAME, PUBSUB_VERSION,
-                                 credentials=credentials)
-    except ApplicationDefaultCredentialsError as ex:
-        logging.error('Failed to get credential.')
-    except:
-        logging.error('Failed to get the pubsub service handle.')
-
-    return None
+class PubSubException(Exception):
+    """Exception to be raised when the test to push to prod failed."""
+    pass
 
 
-def publish_notifications(topic, messages=[]):
-    """Publishes a test result notification to a given pubsub topic.
+class PubSubClient(object):
+    """A generic pubsub client. """
+    def __init__(self, credential_file=CLOUD_SERVICE_ACCOUNT_FILE):
+        """Constructor for PubSubClient.
 
-    @param topic: The Cloud pubsub topic.
-    @param messages: A list of notification messages.
+        @param credential_file: The credential filename.
+        @raises PubSubException if the credential file does not exist or
+            corrupted.
+        """
+        self.credential_file = credential_file
+        self.credential = self._get_credential()
 
-    @returns A list of pubsub message ids, and empty if fails.
-    """
-    pubsub = _get_pubsub_service()
-    if pubsub:
+    def _get_credential(self):
+        """Gets the pubsub service api handle."""
+        if not os.path.isfile(self.credential_file):
+            logging.error('No credential file found')
+            raise PubSubException("Credential file does not exists:"
+                    + self.credential_file)
+        try:
+            credential = GoogleCredentials.from_stream(self.credential_file)
+            if credential.create_scoped_required():
+                credential = credential.create_scoped(PUBSUB_SCOPES)
+            return credential
+        except ApplicationDefaultCredentialsError as ex:
+            logging.error('Failed to get credential.')
+        except:
+            logging.error('Failed to get the pubsub service handle.')
+
+        raise PubSubException("Credential file does not exists:"
+                + self.credential_file)
+
+    def _get_pubsub_service(self):
+        try:
+            return discovery.build(PUBSUB_SERVICE_NAME, PUBSUB_VERSION,
+                                   credentials=self.credential)
+        except:
+            logging.error('Failed to get pubsub resource object.')
+            raise PubSubException("Failed to get pubsub resource object")
+
+    def publish_notifications(self, topic, messages=[]):
+        """Publishes a test result notification to a given pubsub topic.
+
+        @param topic: The Cloud pubsub topic.
+        @param messages: A list of notification messages.
+
+        @returns A list of pubsub message ids, and empty if fails.
+
+        @raises PubSubException if failed to publish the notification.
+        """
+        pubsub = self._get_pubsub_service()
         try:
             body = {'messages': messages}
             resp = pubsub.projects().topics().publish(topic=topic,
@@ -68,6 +92,5 @@
                     logging.debug('Published notification message')
                     return msgIds
         except:
-            pass
-    logging.error('Failed to publish test result notifiation.')
-    return []
+            logging.error('Failed to publish test result notifiation.')
+            raise PubSubException("Failed to publish the notifiation.")