How to execute commands in docker compose files [duplicate] - postgresql

Question

This question already has answers here:
How to create User/Database in script for Docker Postgres
(9 answers)
Closed 8 months ago.
I have a very complex environment, there are two services which named as A service and B service depend on service postgresql, but A and B use difference super user. so once I start the service postgresql, I need create another superuser for service B.
This is a part of docker compose file :
postgres:
image: postgres:13.4
container_name: postgresql
hostname: postgresql
volumes:
- 'postgres_data:/var/lib/postgresql/data'
environment:
POSTGRES_DB: keycloak
POSTGRES_USER: keycloak
POSTGRES_PASSWORD: password
command: ["CREATE ROLE postgres LOGIN SUPERUSER; | ALTER USER postgres CREATEDB CREATEROLE LOGIN INHERIT REPLICATION BYPASSRLS;"]
enter image description here
In the environments, I already setup the default user, password and DB in service postgresql for service A, BUT I’d like to create another super user for service B once service postgresql started, does there any one know how to write the commands. many thanks.
I think this grammer is wrong: command: ["CREATE ROLE postgres LOGIN SUPERUSER; | ALTER USER postgres CREATEDB CREATEROLE LOGIN INHERIT REPLICATION BYPASSRLS;"]

Answer 1

The issue with running commands on container startup is that you need the database to be up to be able to run the commands. By overriding the command: on the container, you replace the normal command which is to start Postgres. So with a new command, Postgres will never start.
You can run the command from a different container once Postgres is started. The command-runner container uses psql to connect to the database and run the command. It also uses the postgres docker image, but because it overrides the command on the container, this container doesn't start a database. It only runs the command.
Here's what I've come up with.
version: "3"
services:
postgres:
image: postgres
environment:
- POSTGRES_USER=keycloak
- POSTGRES_PASSWORD=password
- POSTGRES_DB=keycloak
command-runner:
image: postgres
command: /bin/sh -c 'sleep 10 && PGPASSWORD=password psql -U keycloak -h postgres -d keycloak -c "CREATE ROLE postgres LOGIN SUPERUSER; ALTER USER postgres CREATEDB CREATEROLE LOGIN INHERIT REPLICATION BYPASSRLS;"'
depends_on:
- postgres
I had to put in a sleep 10 command in the command-runner container for it to wait for Postgres to be ready to accept connections.
I also removed the | you had in your command before ALTER USER. I got a syntax error on it.