In my Django project, I have a CI workflow for running tests, which requires a Postgres service. Recently a new app introduced heavier packages such as pandas, matplotlib, pytorch and so on and this increased the run-tests job time from 2 to 12 minutes which is absurd. Also in my project, I have a base Docker image with Python and these packages that are heavier to speed up the build of the images. So I was thinking to use this same image in the workflow when running the steps because the packages would be loaded already.

Unfortunately, all goes well until it reaches the step to actually run the tests because it seems that the postgres service is not connected with the container and I get the following error:

psycopg2.OperationalError: could not connect to server: Connection refused
	Is the server running on host "localhost" (127.0.0.1) and accepting
	TCP/IP connections on port 5432?

This is my workflow right now. Any ideas on what I am doing wrong?

name: server-ci
on:

pull_request:

types: [opened]
env:

DJANGO_SETTINGS_MODULE: settings_test
jobs:
run-tests:

name: Run tests
runs-on: ubuntu-latest

container:
  image: myimage/django-server:base
  credentials:
    username: ${{ secrets.DOCKERHUB_USERNAME }}
    password: ${{ secrets.DOCKERHUB_PASSWORD }}
  ports:
    - 8000:8000

services:
  postgres:
    image: postgres
    env:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: admin
      POSTGRES_DB: mydb
    ports:
      - 5432:5432
    options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5

env:
  POSTGRES_HOST: localhost
  POSTGRES_PORT: 5432
  POSTGRES_PASSWORD: admin
  POSTGRES_USER: postgres

steps:
  - name: Checkout repository
    uses: actions/checkout@v2

  - name: Cache dependencies
    uses: actions/cache@v2
    with:
      path: /opt/venv
      key: /opt/venv-${{ hashFiles('**/requirements.txt') }}

  - name: Install dependencies
    run: |
      python -m pip install --upgrade pip
      python -m pip install -r requirements.txt

    if: steps.cache.outputs.cache-hit != 'true'
  - name: Run tests
    run: |
      ./manage.py test --parallel --verbosity=2