Google Cloud Function triggered by Pub/Sub message being sent on certain topic.

This function is simple example of cloud function with Pub/Sub trigger type which send message to Slack channel on behalf of the user(Bot). User will be defined by user token from Slack.

We will use test slack channel test-webshop-cf to test how this function works.

Runtime: Node.js

Guidebook to run this function

1. Clone this repo

git clone [email protected]:lemon57/cloud-function-pubsub-slack-msg.git

2. Define Slack user SLACK_TOKEN and SLACK_CHANNEL_ID in .env file.
   You can find user SLACK_TOKEN -> Slack user toke.
   And SLACK_CHANNEL_ID you can find in description of the channel in Slack.
3. Deploy this function to GC. Wait a few min ☕

gcloud functions deploy <CF_NAME> \
     --trigger-resource <PUB_SUB_TOPIC_NAME> \
     --trigger-event google.pubsub.topic.publish \
     --region=<REGION_NAME> \
     --runtime=<CF_RUNTIME>

Replace PUB_SUB_TOPIC_NAME by your topic name. Define your own.
Replace REGION_NAME by region of current project.
Replace CF_RUNTIME by actual runtime, in our case is nodejs16

4. Check that the function deployed successfully: by command or through GCC UI.

gcloud functions describe <CF_NAME> --region=<REGION_NAME>

5. Invoke function directly by command:

gcloud functions call <CF_NAME> --data '{"data":"R29vZ2xlIGNsb3VkIGZ1bmN0aW9uIHdvcmtzaG9w"}'

This string R29vZ2xlIGNsb3VkIGZ1bmN0aW9uIHdvcmtzaG9w base64 encoded. To use your specific message and make it base64 encoded you can use this resource base64encode

or by sending message to certain topic by command:

gcloud pubsub topics publish projects/<PROJECT_NAME>/topics/<TOPIC_NAME> --message Hello

Replace PROJECT_NAME by our current boozt project name. Replace TOPIC_NAME by topic name which you find by following command:

gcloud pubsub topics list | grep <KEY_WORD_FROM_TOPIC_NAME>

Replace KEY_WORD_FROM_TOPIC_NAME by topic name which you just recently created when deploy the function.

6. Check the logs:

gcloud functions logs read --execution-id=<EXECUTION-ID> --region=<REGION_NAME>

Take EXECUTION_ID from the output after executing these commands: gcloud functions call or gcloud pubsub topics publish.

6. Check slack channel test-webshop-cf

Enjoy 🎆