Docker is not getting Postgres environment variables - postgresql

Question

Docker is using the variables from my .env file and i keep getting the error:
Unhandled rejection SequelizeConnectionError: role "eli" does not
exist
I would like for Postgres to get the variables from the environment set in docker-compose.yml
.env
POSTGRES_PORT=5432
POSTGRES_DB=elitest4
POSTGRES_USER=eli
POSTGRES_PASSWORD=
docker-compose.yml
# docker-compose.yml
version: "3"
services:
app:
build: .
depends_on:
- database
ports:
- 8000:8000
environment:
- POSTGRES_HOST=database
env_file:
- .env
database:
image: postgres:9.6.8-alpine
environment: # postgress should be getting these variables, not the variables set in the env file thats for localhost
POSTGRES_PASSWORD: password
POSTGRES_USER: user
POSTGRES_DB: db
volumes:
- pgdata:/var/lib/postgresql/pgdata
ports:
- 8002:5432
env_file:
- .env
react_client:
build:
context: ./client
dockerfile: Dockerfile
image: react_client
working_dir: /home/node/app/client
volumes:
- ./:/home/node/app
ports:
- 8001:8001
env_file:
- ./client/.env
volumes:
pgdata:

Answer 1

TL/DR
Try updating the docker-compose service database environment section as follows:
environment:
POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-password}
POSTGRES_USER: ${POSTGRES_USER:-user}
POSTGRES_DB: ${POSTGRES_DB:-db}
Also notice that if you would like to see how each bound variable ultimately evaluates in Compose you can run the following command to see the "effective" compose file:
$ docker-compose config
This command will print out what your compose file looks like with all variable substitution replaced with its evaluation.
See the Environment variables in Compose and the Variable substitution sections in the documentation.
Pay close attention to this section:
When you set the same environment variable in multiple files, here’s
the priority used by Compose to choose which value to use:
1. Compose file
2. Shell environment variables
3. Environment file Dockerfile
4. Variable is not defined
In the example below, we set the same environment variable on an Environment file, and the Compose file:
$ cat ./Docker/api/api.env
NODE_ENV=test
$ cat docker-compose.yml
version: '3'
services:
api:
image: 'node:6-alpine'
env_file:
- ./Docker/api/api.env
environment:
- NODE_ENV=production
When you run the container, the environment variable defined in the Compose file takes precedence.
$ docker-compose exec api node
process.env.NODE_ENV 'production'
Having any ARG or ENV setting in a Dockerfile evaluates only if there is no Docker Compose entry for environment or env_file.
Specifics for NodeJS containers
If you have a package.json entry for script:start like NODE_ENV=test node server.js, then this overrules any setting in your docker-compose.yml file.