|
|
@@ -0,0 +1,286 @@
|
|
|
+# Quickstart: Compose and Django
|
|
|
+
|
|
|
+This quick-start guide demonstrates how to use Docker Compose to set up and run a simple Django/PostgreSQL app. Before starting,
|
|
|
+[install Compose](https://docs.docker.com/compose/install/).
|
|
|
+
|
|
|
+## Define the project components
|
|
|
+
|
|
|
+For this project, you need to create a Dockerfile, a Python dependencies file,
|
|
|
+and a `docker-compose.yml` file. (You can use either a `.yml` or `.yaml` extension for this file.)
|
|
|
+
|
|
|
+1. Create an empty project directory.
|
|
|
+
|
|
|
+ You can name the directory something easy for you to remember. This directory is the context for your application image. The directory should only contain resources to build that image.
|
|
|
+
|
|
|
+2. Create a new file called `Dockerfile` in your project directory.
|
|
|
+
|
|
|
+ The Dockerfile defines an application's image content via one or more build
|
|
|
+ commands that configure that image. Once built, you can run the image in a
|
|
|
+ container. For more information on `Dockerfile`, see the [Docker user guide](https://docs.docker.com/get-started/)
|
|
|
+ and the [Dockerfile reference](https://docs.docker.com/engine/reference/builder/).
|
|
|
+
|
|
|
+3. Add the following content to the `Dockerfile`.
|
|
|
+
|
|
|
+ ```dockerfile
|
|
|
+ # syntax=docker/dockerfile:1
|
|
|
+ FROM python:3
|
|
|
+ ENV PYTHONDONTWRITEBYTECODE=1
|
|
|
+ ENV PYTHONUNBUFFERED=1
|
|
|
+ WORKDIR /code
|
|
|
+ COPY requirements.txt /code/
|
|
|
+ RUN pip install -r requirements.txt
|
|
|
+ COPY . /code/
|
|
|
+ ```
|
|
|
+
|
|
|
+ This `Dockerfile` starts with a [Python 3 parent image](https://hub.docker.com/r/library/python/tags/3/).
|
|
|
+ The parent image is modified by adding a new `code` directory. The parent image is further modified
|
|
|
+ by installing the Python requirements defined in the `requirements.txt` file.
|
|
|
+
|
|
|
+4. Save and close the `Dockerfile`.
|
|
|
+
|
|
|
+5. Create a `requirements.txt` in your project directory.
|
|
|
+
|
|
|
+ This file is used by the `RUN pip install -r requirements.txt` command in your `Dockerfile`.
|
|
|
+
|
|
|
+6. Add the required software in the file.
|
|
|
+
|
|
|
+ ```python
|
|
|
+ Django>=3.0,<4.0
|
|
|
+ psycopg2>=2.8
|
|
|
+ ```
|
|
|
+
|
|
|
+7. Save and close the `requirements.txt` file.
|
|
|
+
|
|
|
+8. Create a file called `docker-compose.yml` in your project directory.
|
|
|
+
|
|
|
+ The `docker-compose.yml` file describes the services that make your app. In
|
|
|
+ this example those services are a web server and database. The compose file
|
|
|
+ also describes which Docker images these services use, how they link
|
|
|
+ together, any volumes they might need to be mounted inside the containers.
|
|
|
+ Finally, the `docker-compose.yml` file describes which ports these services
|
|
|
+ expose. See the [`docker-compose.yml` reference](https://docs.docker.com/compose/compose-file/) for more
|
|
|
+ information on how this file works.
|
|
|
+
|
|
|
+9. Add the following configuration to the file.
|
|
|
+
|
|
|
+ ```yaml
|
|
|
+ services:
|
|
|
+ db:
|
|
|
+ image: postgres
|
|
|
+ volumes:
|
|
|
+ - ./data/db:/var/lib/postgresql/data
|
|
|
+ environment:
|
|
|
+ - POSTGRES_DB=postgres
|
|
|
+ - POSTGRES_USER=postgres
|
|
|
+ - POSTGRES_PASSWORD=postgres
|
|
|
+ web:
|
|
|
+ build: .
|
|
|
+ command: python manage.py runserver 0.0.0.0:8000
|
|
|
+ volumes:
|
|
|
+ - .:/code
|
|
|
+ ports:
|
|
|
+ - "8000:8000"
|
|
|
+ environment:
|
|
|
+ - POSTGRES_NAME=postgres
|
|
|
+ - POSTGRES_USER=postgres
|
|
|
+ - POSTGRES_PASSWORD=postgres
|
|
|
+ depends_on:
|
|
|
+ - db
|
|
|
+ ```
|
|
|
+
|
|
|
+ This file defines two services: The `db` service and the `web` service.
|
|
|
+
|
|
|
+ > Note:
|
|
|
+ >
|
|
|
+ > This uses the build in development server to run your application
|
|
|
+ > on port 8000. Do not use this in a production environment. For more
|
|
|
+ > information, see [Django documentation](https://docs.djangoproject.com/en/3.1/intro/tutorial01/#the-development-server){: target="_blank" rel="noopener" class="_”}.
|
|
|
+
|
|
|
+10. Save and close the `docker-compose.yml` file.
|
|
|
+
|
|
|
+## Create a Django project
|
|
|
+
|
|
|
+In this step, you create a Django starter project by building the image from the build context defined in the previous procedure.
|
|
|
+
|
|
|
+1. Change to the root of your project directory.
|
|
|
+
|
|
|
+2. Create the Django project by running the [docker compose run](https://docs.docker.com/engine/reference/commandline/compose_run/)
|
|
|
+ command as follows.
|
|
|
+
|
|
|
+ ```console
|
|
|
+ sudo docker compose run web django-admin startproject composeexample .
|
|
|
+ ```
|
|
|
+
|
|
|
+ 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`.
|
|
|
+
|
|
|
+ Once the `web` service image is built, Compose runs it and executes the
|
|
|
+ `django-admin startproject` command in the container. This command
|
|
|
+ instructs Django to create a set of files and directories representing a
|
|
|
+ Django project.
|
|
|
+
|
|
|
+3. After the `docker compose` command completes, list the contents of your project.
|
|
|
+
|
|
|
+ ```console
|
|
|
+ $ ls -l
|
|
|
+
|
|
|
+ drwxr-xr-x 2 root root composeexample
|
|
|
+ drwxr-xr-x 3 root root data
|
|
|
+ -rw-rw-r-- 1 user user docker-compose.yml
|
|
|
+ -rw-rw-r-- 1 user user Dockerfile
|
|
|
+ -rwxr-xr-x 1 root root manage.py
|
|
|
+ -rw-rw-r-- 1 user user requirements.txt
|
|
|
+ ```
|
|
|
+
|
|
|
+ If you are running Docker on Linux, the files `django-admin` created are
|
|
|
+ owned by root. This happens because the container runs as the root user.
|
|
|
+ Change the ownership of the new files.
|
|
|
+
|
|
|
+ Do not change the permission of the data folder where Postgres has its file, otherwise Postgres will not be able to start due to permission issues.
|
|
|
+
|
|
|
+ ```console
|
|
|
+ sudo chown -R $USER:$USER composeexample manage.py
|
|
|
+ ```
|
|
|
+
|
|
|
+ If you are running Docker on Mac or Windows, you should already
|
|
|
+ have ownership of all files, including those generated by
|
|
|
+ `django-admin`. List the files just to verify this.
|
|
|
+
|
|
|
+ ```console
|
|
|
+ $ ls -l
|
|
|
+
|
|
|
+ total 32
|
|
|
+ -rw-r--r-- 1 user staff 145 Feb 13 23:00 Dockerfile
|
|
|
+ drwxr-xr-x 6 user staff 204 Feb 13 23:07 composeexample
|
|
|
+ -rw-r--r-- 1 user staff 159 Feb 13 23:02 docker-compose.yml
|
|
|
+ -rwxr-xr-x 1 user staff 257 Feb 13 23:07 manage.py
|
|
|
+ -rw-r--r-- 1 user staff 16 Feb 13 23:01 requirements.txt
|
|
|
+ ```
|
|
|
+
|
|
|
+### Connect the database
|
|
|
+
|
|
|
+In this section, you set up the database connection for Django.
|
|
|
+
|
|
|
+1. In your project directory, edit the `composeexample/settings.py` file.
|
|
|
+
|
|
|
+2. Replace the `DATABASES = ...` with the following:
|
|
|
+
|
|
|
+ ```python
|
|
|
+ # settings.py
|
|
|
+
|
|
|
+ import os
|
|
|
+
|
|
|
+ [...]
|
|
|
+
|
|
|
+ DATABASES = {
|
|
|
+ 'default': {
|
|
|
+ 'ENGINE': 'django.db.backends.postgresql',
|
|
|
+ 'NAME': os.environ.get('POSTGRES_NAME'),
|
|
|
+ 'USER': os.environ.get('POSTGRES_USER'),
|
|
|
+ 'PASSWORD': os.environ.get('POSTGRES_PASSWORD'),
|
|
|
+ 'HOST': 'db',
|
|
|
+ 'PORT': 5432,
|
|
|
+ }
|
|
|
+ }
|
|
|
+ ```
|
|
|
+
|
|
|
+ These settings are determined by the
|
|
|
+ [postgres](https://hub.docker.com/_/postgres) Docker image
|
|
|
+ specified in `docker-compose.yml`.
|
|
|
+
|
|
|
+3. Save and close the file.
|
|
|
+
|
|
|
+4. Run the [docker compose up](https://docs.docker.com/engine/reference/commandline/compose_up/) command from the top level directory for your project.
|
|
|
+
|
|
|
+ ```console
|
|
|
+ $ docker compose up
|
|
|
+
|
|
|
+ djangosample_db_1 is up-to-date
|
|
|
+ Creating djangosample_web_1 ...
|
|
|
+ Creating djangosample_web_1 ... done
|
|
|
+ Attaching to djangosample_db_1, djangosample_web_1
|
|
|
+ db_1 | The files belonging to this database system will be owned by user "postgres".
|
|
|
+ db_1 | This user must also own the server process.
|
|
|
+ db_1 |
|
|
|
+ db_1 | The database cluster will be initialized with locale "en_US.utf8".
|
|
|
+ db_1 | The default database encoding has accordingly been set to "UTF8".
|
|
|
+ db_1 | The default text search configuration will be set to "english".
|
|
|
+
|
|
|
+ <...>
|
|
|
+
|
|
|
+ web_1 | July 30, 2020 - 18:35:38
|
|
|
+ web_1 | Django version 3.0.8, using settings 'composeexample.settings'
|
|
|
+ web_1 | Starting development server at http://0.0.0.0:8000/
|
|
|
+ web_1 | Quit the server with CONTROL-C.
|
|
|
+ ```
|
|
|
+
|
|
|
+ At this point, your Django app should be running at port `8000` on
|
|
|
+ your Docker host. On Docker Desktop for Mac and Docker Desktop for Windows, go
|
|
|
+ to `http://localhost:8000` on a web browser to see the Django
|
|
|
+ welcome page.
|
|
|
+
|
|
|
+ 
|
|
|
+
|
|
|
+ > Note:
|
|
|
+ >
|
|
|
+ > On certain platforms (Windows 10), you might need to edit `ALLOWED_HOSTS`
|
|
|
+ > inside `settings.py` and add your Docker host name or IP address to the list.
|
|
|
+ > For demo purposes, you can set the value to:
|
|
|
+ >
|
|
|
+ > ```python
|
|
|
+ > ALLOWED_HOSTS = ['*']
|
|
|
+ > ```
|
|
|
+ >
|
|
|
+ > This value is **not** safe for production usage. Refer to the
|
|
|
+ > [Django documentation](https://docs.djangoproject.com/en/1.11/ref/settings/#allowed-hosts) for more information.
|
|
|
+
|
|
|
+5. List running containers.
|
|
|
+
|
|
|
+ In another terminal window, list the running Docker processes with the `docker ps` or `docker container ls` command.
|
|
|
+
|
|
|
+ ```console
|
|
|
+ $ docker ps
|
|
|
+
|
|
|
+ CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
|
|
|
+ def85eff5f51 django_web "python3 manage.py..." 10 minutes ago Up 9 minutes 0.0.0.0:8000->8000/tcp django_web_1
|
|
|
+ 678ce61c79cc postgres "docker-entrypoint..." 20 minutes ago Up 9 minutes 5432/tcp django_db_1
|
|
|
+ ```
|
|
|
+
|
|
|
+6. Shut down services and clean up by using either of these methods:
|
|
|
+
|
|
|
+ * Stop the application by typing `Ctrl-C` in the same shell in where you
|
|
|
+ started it:
|
|
|
+
|
|
|
+ ```console
|
|
|
+ Gracefully stopping... (press Ctrl+C again to force)
|
|
|
+ Killing test_web_1 ... done
|
|
|
+ Killing test_db_1 ... done
|
|
|
+ ```
|
|
|
+
|
|
|
+ * Or, for a more elegant shutdown, switch to a different shell, and run
|
|
|
+ [docker compose down](https://docs.docker.com/engine/reference/commandline/compose_down/) from the top level of your
|
|
|
+ Django sample project directory.
|
|
|
+
|
|
|
+ ```console
|
|
|
+ $ docker compose down
|
|
|
+
|
|
|
+ Stopping django_web_1 ... done
|
|
|
+ Stopping django_db_1 ... done
|
|
|
+ Removing django_web_1 ... done
|
|
|
+ Removing django_web_run_1 ... done
|
|
|
+ Removing django_db_1 ... done
|
|
|
+ Removing network django_default
|
|
|
+ ```
|
|
|
+
|
|
|
+ Once you've shut down the app, you can safely remove the Django project directory (for example, `rm -rf django`).
|
|
|
+
|
|
|
+## More Compose documentation
|
|
|
+
|
|
|
+* [Docker Compose overview](https://docs.docker.com/compose/)
|
|
|
+* [Install Docker Compose](https://docs.docker.com/compose/install/)
|
|
|
+* [Getting Started with Docker Compose](https://docs.docker.com/compose/gettingstarted/)
|
|
|
+* [Docker Compose Command line reference](https://docs.docker.com/compose/reference/)
|
|
|
+* [Compose file reference](https://docs.docker.com/compose/compose-file/)
|
|
|
+* [Awesome Compose Django sample application](../../django/README.md)
|