Pub/Sub Controller

Description

Fetch the Subscription of the GCP Pub/Sub regularly, and if there is a message execute the script specified by the key in the message.

GCP Pub/SubのSubscriptionを定期的にFetchし、メッセージがあればメッセージ内のキーで指定されたスクリプトを実行する。

Installation and Try to this sample.

1. Create Pub/Sub topic and subscription on GCP. (ex: test-topic/test-sub)
2. pip install pubsub_controller
3. pubsubcontroller init and input your Pub/Sub setting
   (ex: GCP_PROJECT_ID=your project id / SUBSCRIPTION_ID=test-sub)
4. pubsubcontroller subscribe
5. Subscriber will start immediately.
6. Open Another Terminal Window.
7. pubsubcontroller publish test-topic test-message '{"target":"exec_sample","text":"test_text"}'
8. In the Subscriber's window you will see the contents of the message you just published!

How to add running process when message received.

1. Create a new python file under "exec_classes" directory.

• The same Python filename as the name specified by the attribute "target" key of the message to be published is executed.

2. Implement def main (message_data, message_attr) and describe what you want to do after receiving the message.

• "message_data" contains the contents of the received message.
• "message_attr" contains optional attributes of the received message.

Details

• Settings
  pubsub_controller/settings.py Required parameters are set here.
  (It is set automatically by the pubsubcontroller init command)
  

  • GCP PROJECT ID
    Your GCP ProjectID
  • SUBSCRIPTION ID
    Enter the Subscription ID to be used.
    If the Subscription name is projects/hoge-project/subscriptions/fuga, please enter fuga.
  • Interval Second
    Enter the interval to fetch Subscription in seconds.
    

• Subscriber
  If you need a new subscriber, please refer to apps/subscriber/pull/exec_classes/exec_sample.py and create it.

• Pull Subscriber
  This is a resident process that pulls Subscription.

  • config
    For reference, I am creating a supervisor config file.
    apps/subscriber/pull/config/pull_subscriber.ini

• Publisher
  Execute from the CLI or Python script and publish the message to the topic.

  • Exec on CommandLine
    • pubsubcontroller publish test test-message '{"target":"exec_sample","text":"test_text"}'
      
      • arguments
        • arg1 = topic name
        • arg2 = message data
        • arg3 = message attribute(json format)
  • Exec on PythonCode

    from apps.publisher.publish_message import publish
    publish('test-topic', 'test_data', {'target':'exec_sample','text':'test_text'})