Hi, I have suddenly started to get the following error on my Dagster deployment running in Kubernetes. The Daemon restarts and I see:

sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not translate host name "$HOST_NAME" to address: Temporary failure in name resolution

This started happening all of a sudden and my DB is running so that shouldn't be an issue. I am running Dagster version 1.1.3 and HELM chart 1.1.3. Is this a known bug in that version and updating should fix it or is it something else?

Hey Daniel - I haven't seen this error reported before. Any idea where that "$HOST_NAME" reference might be coming from? I don't see that environment variable referenced anywhere in the Dagster codebase

I just replaced the host name here but it is a URL to the RDS DB

Oh i see - yeah that makes me think that your cluster is having trouble reaching your RDS instance

That's what I thought as well but on start-up there's a container called check-db-ready and I can see inside the logs that it establishes a connection to my database. The Daemon does not for some reason

You could try kubectl execing into the daemon container and seeing if its able to resolve the host. But to the original question, no this isn't a known issue - the fact that it happened all of a sudden without upgrading or changing anything makes me suspect that something in the networking setup o the cluster changed

Thanks for the tip! I will look into it 🙂