Lab → scenario

docker-compose wiring

Connect API and database with health checks and persistent storage.

Requirements

Database persistence

Named volume pgdata mounted at /var/lib/postgresql/data No volume — ephemeral container filesystem Bind mount ./data without backup plan in prod

API depends_on

depends_on db with condition: service_healthy depends_on: [db] only No depends_on — retry in app forever

DB password

POSTGRES_PASSWORD from ${DB_PASSWORD} / .env Hard-code password in docker-compose.yml ENV POSTGRES_PASSWORD in Dockerfile