Setup Repo for Dokku Deployment

Setup Repo for Dokku Deployment#

Dokku can be used to deploy an app in several ways:

Git Repository#

Git & GitHub is used extensively by our lab is and is useful beyond dokku. Please ensure you have an account with GitHub and Git installed on your system.

Your project should be version controlled with git which can be done, if it wasn’t cloned already, by running git init in the directory of your project.

Docker deployment#

Docker is used extensively by our lab and is useful beyond dokku, it allows you to prepare your app in a container which can be launched in a number of different platforms. Dokku will recognize a Dockerfile in the root of your repository and automatically build it and deploy it for you, thus ensuring your application will run as intended in production is a matter of constructing a Dockerfile.

With docker installed, you can build and test your own Dockerfile with:

docker build -t yourimage .
# -p [your-system-port]:[the-container-port]
docker run -p 5000:5000 -it yourimage

# your site should then be visible at http://localhost:5000

Example Static Website Dockerfile#

index.html is the entrypoint to the web application and will be shown if someone goes to your app without any url path.

  • your-app/app/index.html

    <html>
<body>
  Hello World!
</body>
</html>

  • your-app/Dockerfile

    # this base image is designed to serve a website in /usr/share/nginx/html/
FROM nginx

# assuming your static website is in the directory app
COPY app /usr/share/nginx/html/

Example Python Flask Dockerfile#

We use gunicorn to serve the flask app in production instead of the app itself which can be launched in development mode by running python app.py.

  • your-app/app.py

    import flask

app = flask.Flask(__name__)

@app.route('/', methods=['GET'])
def index():
  return 'Hello World!'

if __name __ == '__main__':
  app.run(host='127.0.0.1', port=5000)

  • your-app/requirements.txt

    flask
gunicorn

  • your-app/Dockerfile

    # this base image has python setup and ready to go
FROM python

# install dependencies
COPY requirements.txt /app/requirements.txt
RUN pip install -r /app/requirements.txt

# add source to app
COPY . /app
WORKDIR /app

# the port your app uses -- this is essential for dokku deployment
EXPOSE 5000

# what to do when the container starts
CMD gunicorn --bind 0.0.0.0:5000 app:app
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