heroku.md

Heroku

you may use a production-ready web server such as Gunicorn.

$ pip install gunicorn

Now, run your app with:

$ gunicorn manage:app

Gunicorn uses port 8000 instead of 5000.

Heroku Setting Up

Create an account at Heroku.com

Install Git and Heroku Toolbelt

You can find instructions at Heroku.com.

For example, if you are in an AWS EC2 Ubuntu instance, you can use:

$ sudo apt-get install -y git-core
$ wget -qO- https://toolbelt.heroku.com/install-ubuntu.sh | sh

You can check if it worked with:

$ which git
$ which heroku

Now, login at Heroku:

$ heroku login

Authorize your Machine at Heroku

Create and add a SSH Key at Heroku (optional but recommended):

$ ssh-keygen -t rsa
$ heroku keys:add

The public and private keys will be at ~/.ssh.

Now, let's create our app at Heroku:

$ heroku create <app-name>

Addons and Environment Variables:

Now it's time to add the addons and the environment variables to your app at the Heroku server. For the app I mentioned in the beginning, I type:

$ heroku addons:create heroku-postgresql:hobby-dev

When you run this command the output will a url which you should note as HEROKU_POSTGRESQL_URL

$ heroku pg:promote HEROKU_POSTGRESQL_URL
$ heroku config:set MAIL_USERNAME="<login>"
$ heroku config:set MAIL_PASSWORD="<password>"

Deploying!

If everything is good, it's time to deploy your application.

Run this command :

$ git push heroku master

That's it! The app should be running at < app-name >.herokuapp.com.

Using Foreman to Emulate Heroku

The Heroku Toolbet includes Foreman, used to run the app locally through the Procfile for testing purposes. The environment variables set at Heroku must be defined locally. Just create a file var.env with this information:

FLASK_CONFIG=heroku
MAIL_USERNAME=<your-username>
MAIL_PASSWORD=<your-password>

Foreman run is used to run commands under the environment of the application. Foreman start reads the Procfile and executes the tasks in it:

$ foreman run python manage.py deploy
$ foreman start

Configuring Logging

class HerokuConfig(ProductionConfig):
    @classmethod
    def init_app(cls, app):
        ProductionConfig.init_app(app)

    import logging
    from logging import StreamHandler
    file_handler = StreamHandler()
    file_handler.setLevel(logging.WARNING)
    app.logger.addHandler(file_handler)

To let Heroku know what configuration it should use, add this environment variavle :

$ heroku config:set FLASK_CONFIG=heroku