Google Pub/Sub INVALID_PUSH_ENDPOINT error encountered when configuring a push subscription in Google Pub/Sub.

What is Google Pub/Sub INVALID_PUSH_ENDPOINT error encountered when configuring a push subscription in Google Pub/Sub.

Understanding Google Pub/Sub

Google Cloud Pub/Sub is a messaging service that allows you to send and receive messages between independent applications. It is designed to provide reliable, asynchronous, and scalable communication between services. Pub/Sub is often used for event-driven architectures, data streaming, and decoupling systems.

Identifying the Symptom

When configuring a push subscription in Google Pub/Sub, you might encounter the INVALID_PUSH_ENDPOINT error. This error indicates that the push endpoint URL you have specified is either invalid or unreachable, preventing Pub/Sub from delivering messages to your endpoint.

Common Error Message

The error message typically appears as follows:

{ "error": { "code": 400, "message": "INVALID_PUSH_ENDPOINT", "status": "INVALID_ARGUMENT" }}

Understanding the Issue

The INVALID_PUSH_ENDPOINT error occurs when the URL specified for the push endpoint does not meet the requirements or is not accessible. This can happen due to several reasons, such as incorrect URL format, network restrictions, or server configuration issues.

Requirements for Push Endpoints

The URL must be a valid HTTPS endpoint. The endpoint must be publicly accessible over the internet. The server must be configured to handle POST requests from Pub/Sub.

Steps to Fix the Issue

To resolve the INVALID_PUSH_ENDPOINT error, follow these steps:

1. Verify the URL Format

Ensure that the URL is correctly formatted and uses HTTPS. For example:

https://your-domain.com/your-endpoint

2. Check Endpoint Accessibility

Use tools like cURL or Postman to verify that the endpoint is accessible from the internet. Run the following cURL command:

curl -X POST https://your-domain.com/your-endpoint

If the endpoint is not accessible, check your network settings and firewall rules.

3. Configure the Server

Ensure that your server is configured to accept POST requests from Google Pub/Sub. You may need to adjust your server settings or update your application code to handle incoming requests.

4. Update the Push Subscription

If you have made changes to the endpoint or server configuration, update the push subscription in Google Pub/Sub. You can do this using the gcloud command-line tool:

gcloud pubsub subscriptions update your-subscription-name \ --push-endpoint=https://your-domain.com/your-endpoint

Conclusion

By following these steps, you should be able to resolve the INVALID_PUSH_ENDPOINT error and ensure that your push subscription in Google Pub/Sub is correctly configured. For more information, refer to the Google Cloud Pub/Sub documentation.