Docker Usage | Identity Service User Guide

Start the complete stack

docker compose up --build

This command builds the Java application image and starts two services:

db: PostgreSQL 16 on host port 5432, database identity_db.
app: the packaged Spring Boot service on host port 8080.

Use detached mode when terminal logs are not needed continuously:

docker compose up --build -d

Readiness and startup order

The database health check runs pg_isready against identity_db. Compose starts the application only after PostgreSQL reports healthy through depends_on.condition: service_healthy.

After the application starts, Flyway applies migrations and Hibernate validates the schema. Inspect state and logs with:

docker compose ps

docker compose logs -f db
docker compose logs -f app

Environment variables

Variable	Default	Effect
`DB_USERNAME`	`postgres`	Configures the PostgreSQL user and the application's datasource username.
`DB_PASSWORD`	`postgres`	Configures the PostgreSQL password and the application's datasource password.

Compose injects jdbc:postgresql://db:5432/identity_db into the application. The hostname is the Compose service name, so it differs from the localhost URL used by a Maven development run.

The defaults are local development credentials. Use environment-specific secret management outside this portfolio Compose file for any real deployment.

Stop and clean up

Stop containers while keeping them available for a later restart:

docker compose stop

docker compose start

Remove the containers and Compose network:

docker compose down

The current Compose file does not define a persistent database volume. Removing the database container also removes its local database state.

Common Docker checks

Run docker compose config to validate interpolation and structure.
Run docker compose build app to validate the application image without starting services.
Check that ports 5432 and 8080 are free before startup.
Use docker compose logs before rebuilding repeatedly; migration or credential errors are usually visible there.

See Troubleshooting for daemon, port, Flyway, and startup failures.