In this tutorial, we'll look at how to configure GitLab CI to continuously deploy a Django and Docker application to DigitalOcean.

Dependencies:

Django v3.0.4 Docker v19.03.8 Python v3.8.2

Contents

Objectives

By the end of this tutorial, you will be able to:

Deploy Django to DigitalOcean with Docker Configure GitLab CI to continuously deploy Django to DigitalOcean Set up Passwordless SSH Login Configure DigitalOcean's Managed Databases for data persistence

Project Setup

Along with Django and Docker, the demo project that we'll be using includes Postgres, Nginx, and Gunicorn.

Curious about how this project was developed? Check out the Dockerizing Django with Postgres, Gunicorn, and Nginx blog post.

Start by cloning down the base project:

$ git clone https://gitlab.com/testdriven/django-gitlab-digitalocean.git --branch base --single-branch $ cd django-gitlab-digitalocean

To test locally, build the images and spin up the containers:

$ docker-compose up -d --build

Navigate to http://localhost:8000/. You should see:

{ "hello" : "world" }

DigitalOcean

Let's set up DigitalOcean to work with our application.

First, you'll need to sign up for a DigitalOcean account (if you don't already have one), and then generate an access token so you can access the DigitalOcean API.

Add the token to your environment:

$ export DIGITAL_OCEAN_ACCESS_TOKEN =[ your_digital_ocean_token ]

Droplet

Next, create a new Droplet with Docker pre-installed:

$ curl -X POST \ -H 'Content-Type: application/json' \ -H 'Authorization: Bearer ' $DIGITAL_OCEAN_ACCESS_TOKEN '' \ -d '{"name":"django-docker","region":"sfo2","size":"s-2vcpu-4gb","image":"docker-18-06"}' \ "https://api.digitalocean.com/v2/droplets"

Check the status:

$ curl \ -H 'Content-Type: application/json' \ -H 'Authorization: Bearer ' $DIGITAL_OCEAN_ACCESS_TOKEN '' \ "https://api.digitalocean.com/v2/droplets?name=django-docker"

If you have jq installed, then you can parse the JSON response like so:

$ curl \ -H 'Content-Type: application/json' \ -H 'Authorization: Bearer ' $DIGITAL_OCEAN_ACCESS_TOKEN '' \ "https://api.digitalocean.com/v2/droplets?name=django-docker" \ | jq '.droplets[0].status'

The root password should be emailed to you. Retrieve it. Then, once the status of the droplet is active , SSH into the instance as root and update the password when prompted.

Next, generate a new SSH key:

$ ssh-keygen -t rsa

Save the key to /root/.ssh/id_rsa and don't set a password. This will generate a public and private key -- id_rsa and id_rsa.pub, respectively. To set up passwordless SSH login, copy the public key over to the authorized_keys file and set the proper permissions:

$ cat ~/.ssh/id_rsa.pub $ vi ~/.ssh/authorized_keys $ chmod 600 ~/.ssh/authorized_keys $ chmod 600 ~/.ssh/id_rsa

Copy the contents of the private key:

$ cat ~/.ssh/id_rsa

Set it as an environment variable on your local machine:

export PRIVATE_KEY = '-----BEGIN RSA PRIVATE KEY----- MIIEpAIBAAKCAQEA04up8hoqzS1+APIB0RhjXyObwHQnOzhAk5Bd7mhkSbPkyhP1 ... iWlX9HNavcydATJc1f0DpzF0u4zY8PY24RVoW8vk+bJANPp1o2IAkeajCaF3w9nf q/SyqAWVmvwYuIhDiHDaV2A== -----END RSA PRIVATE KEY-----'

Add the key to the ssh-agent:

$ ssh-add - <<< " ${ PRIVATE_KEY } "

To test, run:

$ ssh -o StrictHostKeyChecking = no [email protected]<YOUR_INSTANCE_IP> whoami root

Then, create a new new directory for the app:

$ ssh -o StrictHostKeyChecking = no [email protected]<YOUR_INSTANCE_IP> mkdir /app

Database

Moving along, let's spin up a production Postgres database via DigitalOcean's Managed Databases:

$ curl -X POST \ -H 'Content-Type: application/json' \ -H 'Authorization: Bearer ' $DIGITAL_OCEAN_ACCESS_TOKEN '' \ -d '{"name":"django-docker-db","region":"sfo2","engine":"pg","version":"11","size":"db-s-2vcpu-4gb","num_nodes":1}' \ "https://api.digitalocean.com/v2/databases"

Check the status:

$ curl \ -H 'Content-Type: application/json' \ -H 'Authorization: Bearer ' $DIGITAL_OCEAN_ACCESS_TOKEN '' \ "https://api.digitalocean.com/v2/databases?name=django-docker-db" \ | jq '.databases[0].status'

It should take a few minutes to spin up. Once the status is online , grab the connection information:

$ curl \ -H 'Content-Type: application/json' \ -H 'Authorization: Bearer ' $DIGITAL_OCEAN_ACCESS_TOKEN '' \ "https://api.digitalocean.com/v2/databases?name=django-docker-db" \ | jq '.databases[0].connection'

Example response:

GitLab CI

Sign up for a GitLab account (if necessary), and then create a new project (again, if necessary).

Build Stage

Next, add a GitLab CI/CD config file called .gitlab-ci.yml to the project root:

image : name : docker/compose:1.25.4 entrypoint : [ "" ] services : - docker:dind stages : - build variables : DOCKER_HOST : tcp://docker:2375 DOCKER_DRIVER : overlay2 build : stage : build before_script : - export IMAGE=$CI_REGISTRY/$CI_PROJECT_NAMESPACE/$CI_PROJECT_NAME - export WEB_IMAGE=$IMAGE:web - export NGINX_IMAGE=$IMAGE:nginx script : - apk add --no-cache bash - chmod +x ./setup_env.sh - bash ./setup_env.sh - docker login -u $CI_REGISTRY_USER -p $CI_JOB_TOKEN $CI_REGISTRY - docker pull $IMAGE:web || true - docker pull $IMAGE:nginx || true - docker-compose -f docker-compose.ci.yml build - docker push $IMAGE:web - docker push $IMAGE:nginx

Here, we defined a single build stage where we:

Set the IMAGE , WEB_IMAGE , and NGINX_IMAGE environment variables Install bash Set the appropriate permissions for setup_env.sh Run setup_env.sh Log in to the GitLab Container Registry Pull the images if they exist Build the images Push the images up to the registry

Add the setup_env.sh file to the project root:

#!/bin/sh echo DEBUG = 0 >> .env echo SQL_ENGINE = django.db.backends.postgresql >> .env echo DATABASE = postgres >> .env echo SECRET_KEY = $SECRET_KEY >> .env echo SQL_DATABASE = $SQL_DATABASE >> .env echo SQL_USER = $SQL_USER >> .env echo SQL_PASSWORD = $SQL_PASSWORD >> .env echo SQL_HOST = $SQL_HOST >> .env echo SQL_PORT = $SQL_PORT >> .env

This file will create the required .env file, based on the environment variables found in your GitLab project's CI/CD settings (Settings > CI / CD > Variables). Add the variables based on the connection information.

For example:

SECRET_KEY : 9zYGEFk2mn3mWB8Bmg9SAhPy6F4s7cCuT8qaYGVEnu7huGRKW9 SQL_DATABASE : defaultdb SQL_HOST : django-docker-db-do-user-778274-0.a.db.ondigitalocean.com SQL_PASSWORD : na9tcfew9jw13a2m SQL_PORT : 25060 SQL_USER : doadmin

Once done, commit and push your code up to GitLab to trigger a new build. Make sure it passes. You should see the images in the GitLab Container Registry:

Deploy Stage

Next, add a deploy stage to .gitlab-ci.yml and create a global before_script that's used for both stages:

image : name : docker/compose:1.25.4 entrypoint : [ "" ] services : - docker:dind stages : - build - deploy variables : DOCKER_HOST : tcp://docker:2375 DOCKER_DRIVER : overlay2 before_script : - export IMAGE=$CI_REGISTRY/$CI_PROJECT_NAMESPACE/$CI_PROJECT_NAME - export WEB_IMAGE=$IMAGE:web - export NGINX_IMAGE=$IMAGE:nginx - apk add --no-cache openssh-client bash - chmod +x ./setup_env.sh - bash ./setup_env.sh - docker login -u $CI_REGISTRY_USER -p $CI_JOB_TOKEN $CI_REGISTRY build : stage : build script : - docker pull $IMAGE:web || true - docker pull $IMAGE:nginx || true - docker-compose -f docker-compose.ci.yml build - docker push $IMAGE:web - docker push $IMAGE:nginx deploy : stage : deploy script : - mkdir -p ~/.ssh - echo "$PRIVATE_KEY" | tr -d '\r' > ~/.ssh/id_rsa - cat ~/.ssh/id_rsa - chmod 700 ~/.ssh/id_rsa - eval "$(ssh-agent -s)" - ssh-add ~/.ssh/id_rsa - ssh-keyscan -H 'gitlab.com' >> ~/.ssh/known_hosts - chmod +x ./deploy.sh - scp -o StrictHostKeyChecking=no -r ./.env ./docker-compose.prod.yml [email protected] $DIGITAL_OCEAN_IP_ADDRESS:/app - bash ./deploy.sh

So, in the deploy stage we:

Add the private SSH key to the ssh-agent Copy over the .env and docker-compose.prod.yml files to the remote server Set the appropriate permissions for deploy.sh Run deploy.sh

Add deploy.sh to the project root:

#!/bin/sh ssh -o StrictHostKeyChecking = no [email protected] $DIGITAL_OCEAN_IP_ADDRESS << 'ENDSSH' cd /app export $(cat .env | xargs) docker login -u $CI_REGISTRY_USER -p $CI_JOB_TOKEN $CI_REGISTRY docker pull $IMAGE:web docker pull $IMAGE:nginx docker-compose -f docker-compose.prod.yml up -d ENDSSH

So, after SSHing into the server, we

Navigate to the deployment directory Add the environment variables Log in to the GitLab Container Registry Pull the images Spin up the containers

Add the DIGITAL_OCEAN_IP_ADDRESS and PRIVATE_KEY environment variables to GitLab.

Update the setup_env.sh file:

#!/bin/sh echo DEBUG = 0 >> .env echo SQL_ENGINE = django.db.backends.postgresql >> .env echo DATABASE = postgres >> .env echo SECRET_KEY = $SECRET_KEY >> .env echo SQL_DATABASE = $SQL_DATABASE >> .env echo SQL_USER = $SQL_USER >> .env echo SQL_PASSWORD = $SQL_PASSWORD >> .env echo SQL_HOST = $SQL_HOST >> .env echo SQL_PORT = $SQL_PORT >> .env echo WEB_IMAGE = $IMAGE :web >> .env echo NGINX_IMAGE = $IMAGE :nginx >> .env echo CI_REGISTRY_USER = $CI_REGISTRY_USER >> .env echo CI_JOB_TOKEN = $CI_JOB_TOKEN >> .env echo CI_REGISTRY = $CI_REGISTRY >> .env echo IMAGE = $CI_REGISTRY / $CI_PROJECT_NAMESPACE / $CI_PROJECT_NAME >> .env

Next, add the server's IP to the ALLOWED_HOSTS list in the Django settings.

Commit and push your code to trigger a new build. Once the build passes, navigate to the IP of your instance. You should see:

{ "hello" : "world" }

Test

Finally, update the deploy stage so that it only runs when changes are made to the master branch:

deploy : stage : deploy script : - mkdir -p ~/.ssh - echo "$PRIVATE_KEY" | tr -d '\r' > ~/.ssh/id_rsa - cat ~/.ssh/id_rsa - chmod 700 ~/.ssh/id_rsa - eval "$(ssh-agent -s)" - ssh-add ~/.ssh/id_rsa - ssh-keyscan -H 'gitlab.com' >> ~/.ssh/known_hosts - chmod +x ./deploy.sh - scp -o StrictHostKeyChecking=no -r ./.env ./docker-compose.prod.yml [email protected] $DIGITAL_OCEAN_IP_ADDRESS:/app - bash ./deploy.sh only : - master

To test, create a new develop branch. Add an explanation point after world in urls.py:

def home ( request ): return JsonResponse ({ "hello" : "world!" })

Commit and push your changes to GitLab. Ensure only the build stage runs. Once the build passes open a PR against the master branch and merge the changes. This will trigger a new pipeline with both stages -- build and deploy . Ensure the deploy works as expected:

{ "hello" : "world!" }

--

That's it! You can find the final code in the django-gitlab-digitalocean repo.