Push to deploy a Python (Django) service via Github Actions

2020-08-20

After using ploi to deploy a Laravel app in the past I really enjoyed the simplicity of just using a git push to deploy my application to staging/production. Ploi configures your Github repository to use a webook to notify Ploi if a new commit was made. It then pulls the source and deploys it.

While ploi does not (yet) offer to manage python/django applications, I found a few resources where this functionality is solved with Github/Gitlab actions, which I adapted to my needs.

The following steps can be used to deploy a django app via push to a production branch.

Deployment scripts

For deployment, we make use of two scripts. One is responsible for deploying on the server (deploy_server.sh) while the other is will push the current master branch to production.

deploy_server.sh:

#!/bin/sh
set -e

SCRIPT=`realpath $0`
SCRIPTPATH=`dirname $SCRIPT`
PYTHON="$SCRIPTPATH/../venv/bin/python"
PIP="$SCRIPTPATH/../venv/bin/pip"

echo "Deploying application ..."

cd $(dirname $SCRIPTPATH)

# Update codebase
git fetch origin production
git reset --hard origin/production

$PIP install -r requirements.txt

# collect static stuff
$PYTHON manage.py collectstatic --noinput;

# Migrate database
$PYTHON manage.py migrate

systemctl --user restart django_deploy_test

echo "Application deployed!"

This script will

use a virtualenv from the $PROJECT/venv folder
fetch and reset to the production branch
install all requirements
call collectstatic and migrate
restart the user service

Now let's have a look at the local deploy.sh:

#!/bin/sh
set -e

(git push) || true

git checkout production
git merge master

git push origin production

git checkout master

Push workflow

To trigger the deployment via Github Actions, the following workflow can be used, which takes preconfigured secrets, authenticates over SSH and executes the deploy_server.sh script.

.github/workflows/main.yml

name: deploy on prod push

on:
  push:
    branches: [ production ]

jobs:
  build:
    name: Build
    runs-on: ubuntu-latest
    steps:
    - name: executing remote ssh commands using password
      uses: appleboy/ssh-action@master
      with:
        host: ${{ secrets.HOST }}
        username: ${{ secrets.USER }}
        key: ${{ secrets.PRIVATE_KEY }}
        port: ${{ secrets.PORT }}
        script: |
          /home/username/projects/django_deploy_test/deploy/deploy_server.sh

The secrets can be configured under the Settings tab in a repository:

Setting up the service

The last step is now to configure django with gunicorn as a service and enable it:

.config/systemd/user/django_deploy_test.service

[Unit]
Description=django daemon
After=network.target

[Service]
WorkingDirectory=/home/user/projects/django_deploy_test
ExecStart=/home/user/projects/django_deploy_test/venv/bin/gunicorn --access-logfile - --workers 3 --bind unix:/home/user/projects/django_deploy_test.sock django_deploy_test.wsgi:application

[Install]
WantedBy=multi-user.target

Enable it via: systemctl --user enable django_deploy_test. Because this is installed as a user service, no sudo is needed for restarting it.

And now we are ready to go. After executing the deploy.sh script you can see the github workflow beeing executed: