Can't see Google Pub/Sub Push Notifications on my endpoint

Question

I have configured a Google Pub/Sub topic and can Pull successfully from it. I have also configured a Push subscription, but my endpoint doesn't seem to be receiving any messages from it.

I have a publicly accessible HTTPS server, with a valid SSL certificate signed by a certificate authority and routable by DNS.

I have registered the endpoint, first verifying that I have access to the domain and then registering the endpoint on the Google Cloud Platform Console, as per the instructions here.

I do not have a firewall, and have checked the logs of my endpoint. I can POST to it from my app, but it doesn't receive anything from Google Pub/Sub (To address questions brought up in this post).

Note: my app is not hosted on Google App Engine, but that shouldn't be a problem according to Pub/Sub Documentation and FAQ.

Any idea what might be going on?

Best, Ishaan

Answer 1

If you received no errors when setting up your push subscription, then the best way to find out what is going on is to look at the relevant metrics in Stackdriver. In particular, you would want to look at the Push Request Count for the Pub/Sub Subscription resource type (in the metrics list as "push_request_count"). You can break down this metric by response class and response code to see if push deliveries to your endpoint are being attempted and if so, what response code Cloud Pub/Sub is getting back.