Django fail to connect to postgres database in gitlab ci - django

Question

I have the following .gitlab-ci.yml :
image: python:3.6
stages:
- lint
- test
services:
- postgres:10.1-alpine
cache:
paths:
- /root/.local/share/virtualenvs/
before_script:
- python -V
- pip install pipenv
- pipenv install --dev
lint:
stage: lint
script:
- pipenv run pylint --output-format=text --load-plugins pylint_django project/ | tee pylint.txt
- score=$(sed -n 's/^Your code has been rated at \([-0-9.]*\)\/.*/\1/p' pylint.txt)
- echo "Pylint score was $score"
- pipenv run anybadge --value=$score --file=pylint.svg pylint
artifacts:
paths:
- pylint.svg
test:
stage: test
script:
- pipenv run python manage.py test
And I am connecting to the database like this :
# settings.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql',
'NAME': 'postgres',
'USER': 'postgres',
'PASSWORD': '',
'HOST': 'db', # set in docker-compose.yml
'PORT': 5432 # default postgres port
}
}
For now, I just have this tests in users/tests.py :
from .models import CustomUser
from django.test import TestCase
class LogInTest(TestCase):
def setUp(self):
self.credentials = {
'username': 'testuser',
'password': 'secret'}
CustomUser.objects.create_user(**self.credentials)
def testLogin(self):
# send login data
response = self.client.post('/users/login/', self.credentials, follow=True)
# should be logged in now
self.assertTrue(response.context['user'].is_authenticated)
Which fails with the following error :
psycopg2.OperationalError: could not translate host name "db" to address: Name or service not known
In development, I use the following docker-compose.yml file :
version: '3.3'
services:
db:
image: postgres:10.1-alpine
volumes:
- postgres_data:/var/lib/postgresql/data/
web:
build: .
command: python /code/manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- 8000:8000
environment:
- SECRET_KEY=changemeinprod
depends_on:
- db
volumes:
postgres_data:
With this Dockerfile :
FROM python:3.6
# Set environment varibles
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
# Set work directory
WORKDIR /code
# Install dependencies
RUN pip install --upgrade pip
RUN pip install pipenv
COPY ./Pipfile /code/Pipfile
RUN pipenv install --deploy --system --skip-lock --dev
# Copy project
COPY . /code/
I don't understand why the app cab't connect to the database in the CI but connect just fine in the development ENV with docker

Answer 1

In your docker-compose.yml you set the service name as db, and django settings.py for use db, but in gitlab will use the image name as the name of the service, postgres in case.
You have two options:
1 - Use environments variables in settings.py, some example here
2 - Set a alias in gitlab-ci.yml, like:
services:
- name: postgres:10.1-alpine
alias: db
link: gitlab docs