Dockerize django app along side with cucumber test - django

Question

Here is the case. I have simple django app with cucumber tests. I dockerized the django app and it works perfect, but I want to dockerize the cucumber test too and run them. Here is my project sturcutre:
-cucumber_drf_tests
-feature
-step_definitions
axiosinst.js
config.js
package.json
cucumber.js
Dockerfile
package-lock.json
-project_apps
-common
docker-compose.yaml
Dockerfile
manage.py
requirements.txt
Here is my cucumber_drf_tests/Dockerfile
FROM node:12
WORKDIR /app/src
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 8000
CMD ["yarn", "cucumber-drf"] (this is how I run my test locally)
My second Dockerfile
FROM python:3.8
ENV PYTHONUNBUFFERED=1
RUN mkdir -p /app/src
WORKDIR /app/src
COPY requirements.txt /app/src
RUN pip install -r requirements.txt
COPY . /app/src
And my docker-compose file
version: "3.8"
services:
test:
build: ./cucumber_drf_tests
image: cucumber_test
container_name: cucumber_container
ports:
- 8000:8000
depends_on:
- app
app:
build: .
image: app:django
container_name: django_rest_container
ports:
- 8000:8000
volumes:
- .:/django #describes a folder that resides on our OS within the container
command: >
bash -c "python manage.py migrate
&& python manage.py loaddata ./project_apps/fixtures/dummy_data.json
&& python manage.py runserver 0.0.0.0:8000"
depends_on:
- db
db:
image: postgres
container_name: postgres_db
volumes:
- ./data/db:/var/lib/postgresql/data
environment:
- POSTGRES_DB=postgres
- POSTGRES_USER=bla
- POSTGRES_PASSWORD=blaa
If I remove I remove test service and run the tests locally everything is fine, but otherwise I got different errors the last one is:
Bind for 0.0.0.0:8000 failed: port is already allocated
It is logic I know, but how to tell to test_container to make the API calls to the address of the running django_rest_container. Maybe this dummy question but I am new of containers world so every sharing of good practice is wellcomed

Answer 1

The issue is in exposing the ports. You are exposing both app and test on the same port (8000). For container you can keep it same. But for host it has to be different.
<host port> : <container port>
This is how ports are mapped in docker. So either change the host port in app or test to different port like below.
For app keep below ports:
7500:8000
Now your app will be accessible at port 7500 and test at 8000