We’re getting this same error this morning when trying to deploy to our instance in london:
Error: 09:20:39.893 [error] Postgrex.Protocol (#PID<0.137.0>) failed to connect: ** (DBConnection.ConnectionError) tcp connect (top2.nearest.of.atlas-review-db.internal:5432): non-existing domain - :nxdomain
We deployed fine yesterday and nothing else changed, I simply updated an existing PR
[edit] perhaps related to Issues in LHR region?