Merge pull request #6 from epidemicsound/refinements

Liveness callback and raise on missing environment variable

README.md

@@ -7,12 +7,12 @@ This module exposes the necessary API to create a worker which starts polling me
 We can install the library through github by writing the dependency in `requirements.txt` as:
 
 ```
-https://github.com/epidemicsound/aws-sqs-worker/releases/download/v0.0.1/aws_sqs_worker-0.0.1-py3-none-any.whl
+https://github.com/epidemicsound/aws-sqs-worker/releases/download/v0.0.2/aws_sqs_worker-0.0.2-py3-none-any.whl
 ```
 
-Replace 0.0.1 with the desired version, on both places in the url!
+Replace 0.0.2 with the desired version, on both places in the url!
 
-If using pipenv, you can also run `pipenv install https://github.com/epidemicsound/aws-sqs-worker/releases/download/v0.0.1/aws_sqs_worker-0.0.1-py3-none-any.whl`.
+If using pipenv, you can also run `pipenv install https://github.com/epidemicsound/aws-sqs-worker/releases/download/v0.0.2/aws_sqs_worker-0.0.2-py3-none-any.whl`.
 
 ## Steps necessary to create a worker for the process:
 

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name='aws-sqs-worker',
-    version='0.0.1',
+    version='0.0.2',
     description='AWS SQS Worker Module',
     license='MIT',
     long_description=long_description,

worker/worker.py

@@ -9,10 +9,15 @@
 
 
 class QueueServiceWorker:
-    def __init__(self, queue_name, handler, logger):
+    def __init__(self, queue_name, handler, logger, liveness_callback=None):
         self.queue_name = queue_name
         self.handler = handler
         self.logger = logger
+        self.liveness_callback = liveness_callback
+
+        if settings.QUEUE_SERVICE_HOST is None:
+            raise Exception("aws-sqs-worker is missing a 'QUEUE_SERVICE_HOST' environment variable")
+
         self.client = request_client.Client(settings.QUEUE_SERVICE_HOST)
 
         self.run = True
@@ -75,6 +80,9 @@ def _work(self):
                 else:
                     raise Exception('Unhandled error {}', message_type)
 
+            if self.liveness_callback is not None:
+                self.liveness_callback()
+
         self.logger.info('Work loop exited')
 
     def start(self):