Adding Cloud-VPS in case this is an indicator of a broader issue.

It's still unclear why the database isn't resolving - it works by direct IP connection.

We've deployed a hotfix directly to production and the tool is now up. I'll leave this task open until that gets merged back to the repository.

In T247322#5956926, @Samwalton9 wrote:

It's still unclear why the database isn't resolving - it works by direct IP connection.

What is the exact hostname that you were attempting to use? The message above seems to imply that you used the hostname db rather than a fully qualified domain name. Is the database deployed as a Cloud VPS instance or as a Docker container that you are managing?

What is the exact hostname that you were attempting to use? The message above seems to imply that you used the hostname db rather than a fully qualified domain name. Is the database deployed as a Cloud VPS instance or as a Docker container that you are managing?

Yeah, to clarify, this is about the connection between two docker containers in the same instance. The issue is between the twlight and db containers - until now the database has resolved with a hostname of db as expected.

hotfix posted to master. I was able to work around this issue by using the name entry used internally by the docker network manager, eg. s/db/tasks.production_db/g where production is the stack name and db is the service alias
https://github.com/WikipediaLibrary/TWLight/commit/a5c77fdbd0323114fd3c525be56e3dd7b726c6d8
I'll stash the change on prod and pull again once it makes it to the production branch. Will do the same for staging as part of the upcoming rebase.

it's not clear why the alias name spontaneously stopped resolving on both staging and production hosts.

before making that change, I tried a stack redeploy, some manual network dis/reconnects, package updates, and a reboot.

okay, hotfix made it to production branch. dropped the local changes on production host, pulled, and redeployed the stack. Production is looking happy. Staging rebase will be another day.

As an additional data point - Wikilink-Tool uses the same name resolution for its database via django + docker and hasn't run into any issues today.

Sorry did not mean to remove the actual project. Phabriccator sub-projects can be confusing.