Database Availability Race Condition during Intialisation

[sierja]

There is a race condition when bring up this stack with Docker Compose, the application will start before the MySQL instance is ready, preventing the schema being loaded and the seeding from occurring which poisons the stack's persistence.

The db service in the docker-compose.yml should have a health check, such as:

healthcheck:
  test: mysqladmin -p$$MYSQL_ROOT_PASSWORD ping -h localhost
  interval: 20s
  start_period: 10s
  timeout: 10s
  retries: 3

The app service in the docker-compose.yml should require db as a health dependency , such as:

depends_on:
  db:
    condition: service_healthy