I am using Docker Stack to deploy a suite of images to AWS. I have previously been deploying and testing using docker-compose. The compose file provides a Postgres connection string for an RDS instance. Everything is great with Compose.
Now, I’ve modified the compose file to version 3 and added deploy tags. Then, I push the containers to multiple EC2 instances using docker stack deploy
. However, having done this, the app within the container can’t see the RDS instance. It’s fine with compose, just not with stack. Should I be doing something else to enable containers to see remote URLs?
My app is logging
[error] Postgrex.Protocol (#PID<0.299.0>) failed to connect: ** (DBConnection.ConnectionError) tcp connect (*******.*******.eu-west-1.rds.amazonaws.com:5432): non-existing domain - :nxdomain
Thanks,
Lee