Connection refused to GCP LoadBalancer in Kubernetes

This turned out to be a dumb mistake on my part. The gunicorn server was using a bind to 127.0.0.1 instead of 0.0.0.0, so it wasn't accessible from outside of the pod, but worked when I exec-ed into the pod.

The fix in my case was changing the entrypoint of the Dockerfile to

CMD [ "gunicorn", "server:app", "-b", "0.0.0.0:8000", "-w", "3" ]

rebuilding the image and updating the deployment.