simulator-database-migration:latest — alembic.ini appears to hardcode localhost, migration container exits 1 on fresh genlayer up

[theboyplunger0x]

Summary

The yeagerai/simulator-database-migration:latest image fails to boot when genlayer up --headless --numValidators 5 is run on a fresh install. The migration container exits with code 1 because its alembic configuration appears to hardcode sqlalchemy.url to localhost instead of reading DB_URL from the environment. In the docker-compose network, postgres is a service alias — not reachable at localhost from another container.

Repro

Fresh install, macOS on Apple Silicon, Docker Desktop 29.6.1, GenLayer CLI v0.39.2:

genlayer up --headless --numValidators 5

Observed

Containers after boot attempt:

• genlayer-postgres-1 — starts healthy on 5432 ✅
• genlayer-hardhat-1 / genlayer-webdriver-1 — healthy ✅
• genlayer-database-migration-1 — starts, then exits with code 1 ❌
• genlayer-jsonrpc-1 — stays in Created state (depends on migration completing) ❌
• Port 4000 never bound → RPC unreachable → CLI eventually prints "Unable to initialize the GenLayer simulator"

Migration container logs (verbatim tail):

Running migrations online
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError)
  connection to server at "localhost" (::1), port 5432 failed: Connection refused
  connection to server at "localhost" (127.0.0.1), port 5432 failed: Connection refused

Root cause

The migration container's DB_URL env is correctly set to a value pointing at the docker service name postgres, and postgres is reachable at postgres:5432 from the same genlayer_default network (verified via docker inspect). But alembic attempts to connect to localhost:5432 inside the migration container's own namespace, where nothing is listening, so it errors with Connection refused.

The most likely cause is that alembic.ini inside the image hardcodes sqlalchemy.url = ...@localhost/... and env.py doesn't override it with DB_URL.

Fix suggestions

Either:

• Update env.py to override the URL at runtime: config.set_main_option("sqlalchemy.url", os.environ["DB_URL"]) before running migrations
• Or publish an updated alembic.ini that uses the service alias (postgres) as the default host

Environment

• macOS 14 (Darwin 24.6.0), Apple Silicon
• Docker Desktop 29.6.1
• GenLayer CLI v0.39.2
• Image: yeagerai/simulator-database-migration:latest (pulled 2026-07-01)

Impact

Blocks fresh genlayer up on macOS across our lab environment. Workarounds (patching the running container, docker exec overrides) are brittle for CI/dev use.

Happy to test a fix if you have a candidate tag.