I wanted to build a postgres docker container so my spring application can connect to it and use it. After booting up the container my application could not connect to it due to a fatal authentication error.

After unsuccessfully trying to connect to the db with dbeaver I can’t figure out where my problem is.

This is my docker compose file.

version: '2'

services:
  db:
    image: 'postgres:alpine'
    container_name: productServicePostgres
    ports:
      - 0.0.0.0:5432:5432
    environment:
      POSTGRES_DB: "testDB"
      POSTGRES_USER: "test"
      POSTGRES_PASSWORD: "test"

I also tried to start a postgres container from command like this :

docker run --name postgres-0 -e POSTGRES_PASSWORD=test -d testdb -p 0.0.0.0:5432:5432 postgres:alpine

When I’m entering the container with docker exec -it productServicePostgres bash and try to call psql I’m getting the following error message.

psql: error: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: FATAL: role "root" does not exist