Please improve README for the Image

[eximius313]

https://hub.docker.com/_/redmine can be improved:

1. start a database container - PostgreSQL

$ docker run -d --name some-postgres --network some-network -e POSTGRES_PASSWORD=secret -e POSTGRES_USER=redmine postgres

could also contain POSTGRES_DB for the consistency (as MySQL example has it):

$ docker run -d --name some-postgres --network some-network -e POSTGRES_DB=redmine_db -e POSTGRES_USER=redmine -e POSTGRES_PASSWORD=secret postgres

2. start redmine

$ docker run -d --name some-redmine --network some-network -e REDMINE_DB_POSTGRES=some-postgres -e REDMINE_DB_USERNAME=redmine -e REDMINE_DB_PASSWORD=secret redmine

could also include REDMINE_DB_DATABASE in order to differentiate it from REDMINE_DB_POSTGRES and REDMINE_SECRET_KEY_BASE in order to be consistent with docker-compose.yaml:

$ docker run -d --name some-redmine --network some-network -e REDMINE_DB_POSTGRES=some-postgres-ip -e REDMINE_DB_DATABASE=redmine_db -e REDMINE_DB_USERNAME=redmine -e REDMINE_DB_PASSWORD=secret -e REDMINE_SECRET_KEY_BASE=supersecretkey redmine

3. compose.yaml could also have version for Postgresql and be enhanced of volumes and depends_on:

services:
  redmine:
    image: redmine
    restart: always
    environment:
      REDMINE_DB_POSTGRES: postgresql
      REDMINE_DB_DATABASE: redmine_db
      REDMINE_DB_USERNAME: redmine
      REDMINE_DB_PASSWORD: secret
      REDMINE_SECRET_KEY_BASE: supersecretkey
    ports:
      - 8080:3000
    volumes:
      - redmine_data:/usr/src/redmine/files
    depends_on:
      - postgresql

  postgresql:
    image: postgres:17-alpine
    restart: unless-stopped
    environment:
      POSTGRES_DB: redmine_db
      POSTGRES_USER: redmine
      POSTGRES_PASSWORD: secret
    volumes:
      - postgresql_data:/var/lib/postgresql/data

volumes:
  redmine_data:
  postgresql_data:

[yosifkit]

I agree that the compose file could benefit from some volumes.

The rest is left mostly as an exercise for the reader; not every example is meant to show every possible combination of environment variables or even the same set, just a few possible combinations.

---

MYSQL_DATABASE is used because there isn't a database created automatically based on username like there is in the postgres image, so adding POSTGRES_DB is superfluous.

https://github.com/docker-library/docs/tree/0e406d31b1aca6af0da1d7d7a01a3e64a36e872c/postgres#postgres_db:

POSTGRES_DB

This optional environment variable can be used to define a different name for the default database that is created when the image is first started. If it is not specified, then the value of POSTGRES_USER will be used.

https://github.com/docker-library/docs/tree/0e406d31b1aca6af0da1d7d7a01a3e64a36e872c/mysql#mysql_database:

MYSQL_DATABASE

This variable is optional and allows you to specify the name of a database to be created on image startup. If a user/password was supplied (see below) then that user will be granted superuser access (corresponding to GRANT ALL⁠) to this database.