docker-django-postgres

Disclaimer

I'm a Python, Django and Postgres noob - so a lot of this information may already be assumed by anyone trying to configure an application as such.

This is a reference point for myself to take advantage from the several learning points undertaken in getting the application working

This starts off by following the docs.docker.com example on building a Django Postgres admin application with some additional collated information from various other sources and docker tweaking to include PgAdmin4

Setting up the project

Start by installing Django inside a container and symlinking those files back out to the host machine

sudo docker-compose run web django-admin startproject composeexample .

web is the name of the service as defined in the docker-compose.yml file.

composeexample is going to be the name of the django-admin project

This instructs Compose to run django-admin startproject composeexample in a container, using the web service’s image and configuration. Because the web image doesn’t exist yet, Compose builds it from the current directory, as specified by the build: . line in docker-compose.yml.

Linux Note: If you are running Docker on Linux, the files django-admin created are owned by root. This is because the container runs as the Root user. Change the ownership of the new files.

sudo chown -R $USER:$USER .

Connect the databse to Django

In this section, set up the database connection for Django.

1. In the project directory, edit the composeexample/settings.py file
2. Replace the DATABASES = ... with the following:

   # settings.py
   
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql',
            'NAME': 'postgres',
            'USER': 'postgres',
            'PASSWORD': 'postgres',
            'HOST': 'db',
            'PORT': 5432,
        }
    }
   

   These settings are determined by the postgres Docker image specified in docker-compose.yml
3. Save and close the file
4. Run the docker-compose up command from the top level directory for your project

Adding PgAdmin as a web service

This is already part of the docker-compose.yml file and will mostly be setup on the docker-compose up command. For more information view khezen/compose-postgres github

Creating django tables and viewing them in PgAdmin

1. Run the docker-compose up command from the top level directory for your project
2. Once the application has fully started, run migrations to create the tables docker-compose exec web python manage.py migrate
3. Create a super user for django-admin docker-compose exec web python manage.py createsuperuser
4. Open PgAdmin in a web browser localhost:5050
5. login using the environment variables in the docker-compose.yml file
   1. username: pgadmin4@pgadmin.org
   2. password: admin
6. Create a connection to the postgres db
   1. 
7. Give the connection a reasonable name - for this example docker_django_postgres_db
   1. 
8. Enter the credentials. The really cool thing about this - for the Host name\address we can simply use the name of the docker service. In this example, it is simply db
   1. Host name\address : db
   2. port: 5432
   3. Maintenance database: postgres
   4. Username: postgres
   5. Password: postgres
   6. 
9. Check that the tables and super user are created by navigating the sidebar in PgAdmin
   1. 

References

docker django postgres example

create a django project

khezen/compose-postgres github