Postgres Password Secrets in Docker

I needed a way to spin up a postgres container without hardcoding any credentials. But it turns out postgres wants at least POSTGRES_PASSWORD being set.

After some digging, I found out that there is a very non-trivial way to accomplish what I wanted to achieve. It needed the password to be provided in a file and set secrets in the docker-compose.yml. Here is how:

version: '3'
services:
  database:
    container_name: database
    environment:
      POSTGRES_PASSWORD_FILE: /run/secrets/postgres_password
    image: postgis/postgis:13-master
    volumes:
      - /data/database:/var/lib/postgresql/data
    secrets:
      - postgres_password
secrets:
  postgres_password:
    file: ./docker_postgres_password

Notice POSTGRES_PASSWORD_FILE instead of just POSTGRES_PASSWORD. Also notice at the very bottom how I’ve mentioned that postgres_password will be in a file named docker_postgres_password. The contents of this file is simply just the password itself and nothing else.

docker postgres