How do you perform Django database migrations when using Docker-Compose?
DjangoDockerDocker ComposeDjango Problem Overview
I have set up a Docker Django/PostgreSQL app closely following the Django Quick Start instructions on the Docker site.
The first time I run Django's manage.py migrate, using the command sudo docker-compose run web python manage.py migrate
, it works as expected. The database is built inside the Docker PostgreSQL container just fine.
Changes made to the Django app itself are likewise reflected in the Docker Django container, the moment I save them. It's great!
But if I then change a model in Django, and try to update the Postgres database to match the model, no changes are detected so no migration happens no matter how many times I run makemigrations
or migrate
again.
Basically, every time I change the Django model, I have to delete the Docker containers (using sudo docker-compose rm
) and start afresh with a new migration.
I'm still trying to get my head around Docker, and there's an awful lot I don't understand about how it works, but this one is driving me nuts. Why doesn't migrate see my changes? What am I doing wrong?
Django Solutions
Solution 1 - Django
You just have to log into your running docker container and run your commands.
- Build your stack :
docker-compose build -f path/to/docker-compose.yml
- Launch your stack :
docker-compose up -f path/to/docker-compose.yml
- Display docker running containers :
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3fcc49196a84 ex_nginx "nginx -g 'daemon off" 3 days ago Up 32 seconds 0.0.0.0:80->80/tcp, 443/tcp ex_nginx_1
66175bfd6ae6 ex_webapp "/docker-entrypoint.s" 3 days ago Up 32 seconds 0.0.0.0:32768->8000/tcp ex_webapp_1
# postgres docker container ...
4. Get the CONTAINER ID of you django app and log into :
docker exec -t -i 66175bfd6ae6 bash
5. Now you are logged into, then go to the right folder : cd path/to/django_app
- And now, each time you edit your models, run in your container :
python manage.py makemigrations
andpython manage.py migrate
I also recommend you to use a docker-entrypoint for your django docker container file to run automatically :
- collecstatic
- migrate
- runserver or start it with gunicorn or uWSGI
Here is an example (docker-entrypoint.sh
) :
#!/bin/bash
# Collect static files
echo "Collect static files"
python manage.py collectstatic --noinput
# Apply database migrations
echo "Apply database migrations"
python manage.py migrate
# Start server
echo "Starting server"
python manage.py runserver 0.0.0.0:8000
Solution 2 - Django
I use these method:
services:
web:
build: .
image: uzman
command: python manage.py runserver 0.0.0.0:8000
ports:
- "3000:3000"
- "8000:8000"
volumes:
- .:/code
depends_on:
- migration
- db
migration:
image: uzman
command: python manage.py migrate --noinput
volumes:
- .:/code
depends_on:
- db
Using docker
hierarchy we made, the service migration runs after set up the database and before to run the main service. Now when you run your service docker
will run migrations before runs the server; look that migration
server is applied over the same image that web server, it means that all migrations will be taken from your project, avoiding problems.
You avoid made entry point or whatever other thing with this way.
Solution 3 - Django
Have your stack running then fire off a one shot docker-compose run command. E.g
#assume django in container named web
docker-compose run web python3 manage.py migrate
This works great for the built-in (default) SQLite database, but also for an external dockerized database that's listed as dependency. Here's an example docker-compose.yaml file
version: '3'
services:
db:
image: postgres
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- "8000:8000"
depends_on:
- db
Solution 4 - Django
You can use docker exec
command
docker exec -it container_id python manage.py migrate
Solution 5 - Django
you can use docker-entrypoint.sh
or a newer solution would be multiple comments in your docker-compose.yml
version: '3.7'
services:
web:
build: ./
command: >
sh -c "python manage.py collectstatic --noinput &&
python manage.py migrate &&
python manage.py runserver 0.0.0.0:8000"
volumes:
- ./:/usr/src/app/
ports:
- 8000:8000
env_file:
- ./.env
depends_on:
- postgres
postgres:
image: postgres:13.0-alpine
ports:
- 5432:5432
volumes:
- ./data/db:/var/lib/postgresql/data
environment:
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=postgres
- POSTGRES_DB=postgres
Solution 6 - Django
If you have something like this in your docker-compose.yml
version: "3.7"
services:
app:
build:
context: .
dockerfile: docker/app/Dockerfile
ports:
- 8000:8000
volumes:
- ./:/usr/src/app
depends_on:
- db
db:
image: postgres
restart: always
environment:
POSTGRES_USER: docker
POSTGRES_PASSWORD: docker
POSTGRES_DB: docker
Then you can simple run...
~$ docker-compose exec app python manage.py makemigrations
~$ docker-compose exec app python manage.py migrate
Solution 7 - Django
I know this is old, and maybe I am missing something here (if so, please enlighten me!), but why not just add the commands to your start.sh
script, run by Docker to fire up your instance? It will take only a few extra seconds.
N.B. I set the DJANGO_SETTINGS_MODULE
variable to make sure the correct database is used, as I use different databases for development and production (although I know this is not 'best practice').
This solved it for me:
#!/bin/bash
# Migrate the database first
echo "Migrating the database before starting the server"
export DJANGO_SETTINGS_MODULE="edatool.settings.production"
python manage.py makemigrations
python manage.py migrate
# Start Gunicorn processes
echo "Starting Gunicorn."
exec gunicorn edatool.wsgi:application \
--bind 0.0.0.0:8000 \
--workers 3
Solution 8 - Django
Using docker exec, I was getting the following error:
AppRegistryNotReady("Models aren't loaded yet.")
So I used this command instead:
docker-compose -f local.yml run django python manage.py makemigrations
Solution 9 - Django
If you only want to use Dockerfile, you can add ENTRYPOINT[] command. Example how to run .sh script:
FROM python:3.9.4
RUN apt-get update
RUN apt-get install libpq-dev --assume-yes
RUN pip3 install psycopg2
COPY . /app
WORKDIR /app
RUN pip install -r requirements.txt
RUN pip3 install debugpy
ENTRYPOINT ["/app/docker-entrypoint.sh"]
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]