How to Dockerize an Existing Django Application
What is Docker?
Docker is a tool designed to make it easier to create, deploy, and run applications by using containers. Containers allow a developer to package up an application with all of the parts it needs, such as libraries and other dependencies, and deploy it as one package.
Note: This article assumes you already have Docker & Docker Compose installed and know basic Django and Python development.
Create a new file called
Dockerfile in your project root directory
This is simply a file that contains a list of instructions for docker to build our image. Basically it describes all the dependencies you need in your project in the dockerfile.
Add the following to your
# Step 1/10 Here we're creating our image from the python alpine image FROM python:3.8-alpine # Step 2/10 This is just to keep track or show that you own this image MAINTAINER Chuckz Okoye # Step 3/10 This helps avoid complications from running python in containers ENV PYTHONUNBUFFERED=1 # Step 4/10 Here we copy our requirements.txt file to our docker image COPY ./requirements.txt /requirements.txt # Step 5/10 Here we install packages from the requirements file we just copied RUN pip install -r /requirements.txt # Step 6/10 Here we create a directory in our docker image RUN mkdir /code # Step 7/10 Here we set the created directory as our working directory in our docker image WORKDIR /code # Step 8/10 Here we copy the contents of our local code directory to our docker image COPY . /code/ # Step 9/10 Here we create a user to run our application in docker RUN adduser -D user # Step 10/10 Here we switch the docker user to the user we created in step 9 USER user
Next we create a file called
docker-compose.yml in your project root directory
docker-compose.yml file is a tool for defining and running multiple services that make up our application. For example one service may be a
Postgres Database and another our Django application.
Add the following to your
version: "3" services: code: build: context: . ports: - "8000:8000" volumes: - .:/code command: python manage.py runserver 0.0.0.0:8000
This file defines a single service called
code. We set the build context to
. indicating that we're running from our current directory.
ports config we map our project from
8000 on our localhost to
port 8000 in our image.
volume config allows us to work synchronously
with the code folder in our image in real time.
command contains the command that is used to run our application in our docker container. age
Building and Running our Docker image
Now we can build and run our image by using the
docker-compose up command in our terminal. Also to run other django commands from the container, we can use the
docker-compose run followed by our command.
It takes some trial and error to get the working principle down, but once you do, development and deployment would definitely be easier. If you come across any issue setting this up, let me know in the comments section below 🙂
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