Installation

pip install awsPySqsListener

Listening to a queue

Here is a basic code sample:

Standard Listener

from sqs_listener import SqsListener

class MyListener(SqsListener):
    def handle_message(self, body, attributes, messages_attributes):
        run_my_function(body['param1'], body['param2'])

listener = MyListener('my-message-queue', error_queue='my-error-queue', region_name='us-east-1')
listener.listen()

Error Listener

from sqs_listener import SqsListener
class MyErrorListener(SqsListener):
    def handle_message(self, body, attributes, messages_attributes):
        save_to_log(body['exception_type'], body['error_message']

error_listener = MyErrorListener('my-error-queue')
error_listener.listen()

• error_queue (str) - name of queue to push errors.

• force_delete (boolean) - delete the message received from the queue, whether or not the handler function is successful. By default the message is deleted only if the handler function returns with no exceptions

• interval (int) - number of seconds in between polls. Set to 60 by default

• visibility_timeout (str) - Number of seconds the message will be invisible (‘in flight’) after being read. After this time interval it reappear in the queue if it wasn’t deleted in the meantime. Set to ‘600’ (10 minutes) by default

• error_visibility_timeout (str) - Same as previous argument, for the error queue. Applicable only if the error_queue argument is set, and the queue doesn’t already exist.

Running as a Daemon

Logging

logger = logging.getLogger('sqs_listener')
logger.setLevel(logging.INFO)

sh = logging.StreamHandler(sys.stdout)
sh.setLevel(logging.INFO)

formatstr = '[%(asctime)s - %(name)s - %(levelname)s]  %(message)s'
formatter = logging.Formatter(formatstr)

sh.setFormatter(formatter)
logger.addHandler(sh)

logger = logging.getLogger('sqs_listener')
logger.setLevel(logging.INFO)

sh = logging.FileHandler('mylog.log')
sh.setLevel(logging.INFO)

formatstr = '[%(asctime)s - %(name)s - %(levelname)s]  %(message)s'
formatter = logging.Formatter(formatstr)

sh.setFormatter(formatter)
logger.addHandler(sh)

Sending messages

Launcher Example

from sqs_launcher import SqsLauncher

launcher = SqsLauncher('my-queue')
response = launcher.launch_message({'param1': 'hello', 'param2': 'world'})

Important Notes

• The environment variable AWS_ACCOUNT_ID must be set, in addition to the environment having valid AWS credentials (via environment variables or a credentials file)

• For both the main queue and the error queue, if the queue doesn’t exist (in the specified region), it will be created at runtime.

• The error queue receives only two values in the message body: exception_type and error_message. Both are of type str

• If the function that the listener executes involves connecting to a database, you should explicitly close the connection at the end of the function. Otherwise, you’re likely to get an error like this: OperationalError(2006, 'MySQL server has gone away')

Contributing

Fork the repo and make a pull request.