Been struggling with this issue for close to a month now and I am at my wits end.

I have the following docker-compose.yml file:

version: '3.8'

services:
  web:
    container_name: targeting
    build: ./Targeting
    command: python manage.py runserver 0.0.0.0:80
    volumes:
      - ./:/usr/src/project/
    ports:
      - "80:80"

  db:
    env_file:
      - ./.env
    restart: always
    image: postgres
    container_name: postgres
    environment:
      - POSTGRES_DB=${NAME}
      - POSTGRES_USER=${USER}
      - POSTGRES_PASSWORD=${PASSWORD}
      - POSTGRES_PORT=${PORT}
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data/

  pgadmin:
    image: dpage/pgadmin4
    container_name: pgadmin4_container
    restart: always
    ports:
      - "8888:80"
    environment:
      PGADMIN_DEFAULT_EMAIL: [email protected]
      PGADMIN_DEFAULT_PASSWORD: strong-password
    volumes:
      - pgadmin-data:/var/lib/pgadmin

volumes:
  postgres_data:
  pgadmin-data:

and I have the following .env file:

SECRET_KEY=random_secret_key
DEBUG=TRUE

NAME=postgres
USER=postgres
PASSWORD=password
HOST=db
PORT=5432

The following Dockerfile is used to create the python container:

# pull official base image
FROM python:3.11.4-slim-buster

# set work directory
WORKDIR /usr/src/project

# set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1

# install dependencies
RUN pip install --upgrade pip
COPY ../requirements.txt .
RUN pip install -r requirements.txt

# copy project
COPY .. .

On a Windows machine, after a docker compose build and a docker compose up command is issued, the project will be up and running and the django project will connect to the postgres database perfectly fine. I have verified this on two Windows machines. However, on mac or linux, I get a “connection failed: FATAL: password authentication failed for the user “postgres” error and I have no idea why.

my settings.py file for Django looks like this. I use Python decouple to use .env variables.

from decouple import config

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.postgresql",
        "NAME": config('NAME'),
        "USER": config('USER'),
        "PASSWORD": config('PASSWORD'),
        "HOST": config('HOST'),
        "PORT": config('PORT')
    }
}

Anyone have any suggestions? I am guessing it could be something to do with paths, but I have not been able to find out the solution. Thanks.

I have tried credentials for a postgres database on a RDS instance in the env file and that worked fine on the Mac and linux machines.