How to use local DNS in Pyppeteer

Question

I've got a reverse proxy, frontend and backend container. The backend is running Pyppeteer and the reverse proxy is set up with an alias "servicename.localhost" in docker-compose.yml:

networks:
  default:
    aliases:
      - servicename.localhost

This way I'm able to curl --insecure https://servicename.localhost from the backend container, but unfortunately it seems Chromium on the same container ignores that setting and so "servicename.localhost" resolves to 127.0.0.1:

pyppeteer.errors.PageError: net::ERR_CONNECTION_REFUSED at https://servicename.localhost/login

How can I work around this?

It looks like it may be related to DNS prefetching or asynchronous DNS, but there doesn't seem to be a command line flag to disable either of them anymore.

Things I've tried which didn't change anything:

• Adding "--host-rules='MAP servicename.localhost {}'".format(socket.gethostbyaddr('servicename.localhost')[-1][0]) to the pyppeteer.launch args list parameter.
• Adding "--host-resolver-rules=[same as above] to the pyppeteer.launch args list parameter.

Answer 1

I worked around this by changing the TLD from "localhost" to "test".