dead_letter_tests

Dead Letter Topic

These functions test the Pub/Sub retries and dead-letter topics.

Test Cloud Functions

The cloud functions AckPubMessage and BadAckFunc test the subscription retries and dead-letter topics.

Main Pub/Sub topic radio-pluto, has cloud http trigger func BadAckFunc is attached to it that always returns code 500. Since radio-pluto topic is set to retry 5 times, the message will be sent 5 times to BadAckFunc. Once all retries fails, the message will be pushed to pluto-dead-letter topic.

Dead letter topic: pluto-dead-letter has listener AckPubMessage. Once the messages is received this function consumes it. Once consumed message is discarded (if configured).

# Activate  right project configuration
gcloud config configurations activate gcp-experiments
# Note that --runtime go116  is supported as beta
# https://cloud.google.com/functions/docs/concepts/go-runtime
gcloud functions deploy AckPubMessage --runtime go116 --trigger-topic pluto-dead-letter --project=gcp-experiments-334602
# Deploy a http func so we can return a error code (to test retry and dead-letter)
gcloud functions deploy BadAckFunc --runtime go116 --trigger-http --allow-unauthenticated --project=gcp-experiments-334602 --region=us-west1

Testing Message Retries

Pushing messages using command:

# Push a message to a 'radio-pluto' topic
gcloud pubsub topics publish radio-pluto --message='{"name": "GCP", "rating": "12-star"}' --project=gcp-experiments-334602

Then observe the logs for retries.

Multiple Subscriptions on a topic.

This is not tested yet.