Multiple users with docker-compose

[eldarj]

Given a simple docker-compose

version: '3.8'

services:
  psql:
    image: postgres:16-alpine
    container_name: my-psql
    ports:
      - "5432:5432"
    environment:
      - POSTGRES_USER=something
      - POSTGRES_PASSWORD=something
      - POSTGRES_DB=sample

What is the suggest approach for creating multiple users? Ideally with the logic in docker-compose alone. Or if not possible, perhaps with a sh script, but without custom Dockerfiles.

[ImreSamu]

( as a user )
You can effectively use an initialization script by mapping it in your Docker Compose file.

Here are the steps to follow:

1.) Add an Initialization Script: ( /docker-entrypoint-initdb.d/init-database.sh )
For guidance on how to set up this script, please refer to the official Postgres documentation in the Docker Library. They provide helpful examples, such as how to add additional users and databases. You can find these examples here:

• https://github.com/docker-library/docs/tree/master/postgres#initialization-scripts

2.) Configure Docker Compose::
Below is an example that you need to add to your docker-compose file for setting this up:

    volumes:
      - ./init-database.sh:/docker-entrypoint-initdb.d/init-database.sh    

This example is based on a solution found on Stack Overflow ( https://stackoverflow.com/a/61729115/20859909 )

[eldarj]

@ImreSamu Thanks for the comment. Shell script will work perfectly!

Improvement-wise - would it be possible and would we want to update the image itself, to accept multiple values via POSTGRES_USER?

Also what do you mean by this?

( as a user )

Thanks again!

[ImreSamu]

... to update the image itself, to accept multiple values via POSTGRES_USER?

see :

• Create multiple users and databases #151
• Create multiple database READonly users for different cluster #872
• Creation multiple users and databases #240