Deploying app on Heroku

Free allowances

Resources included for free on all plans:

• Nothing

What we need

• 1 Basic $7/dyno per month (recommended) OR
• 1 Eco $5 for 1000 dyno hours/month

What is missing

• 1 PostgreSQL Server Free @ Tecnico

Deploy steps

1. Signup to Heroku

2. Install the Heroku CLI

3. Create App appname from the CLI

   heroku create appname

4. Heroku wants your app to reside standalone in a Git repository. Create a new private repository to hold your app on Github.com and push your app there. Notice that Heroku wants most files to be at the root of the repository (e.g., Procfile, runtime.txt, etc.)

5. Add a new git remote to your app repository using the Heroku CLI. This remote heroku is the one you will push to whennever you want to deploy the app to Heroku.

   heroku git:remote -a appname

   If the command is successful you will be able to ommit the -a appname part since heroku uses this information.

   Before our first deploy we need to set a couple of standard environment variables:

   heroku config:set FLASK_APP=app

   heroku config:set FLASK_DEBUG=0

   heroku config:set FLASK_ENV=production

   Generate your app's unique secret key

   python3 -c 'import secrets; print(secrets.token_hex())'

   Set the environment variable

   heroku config:set FLASK_SECRET_KEY='your_key_from_the_previous_step'

   heroku config:set WEB_CONCURRENCY=2

6. We will set the DATABASE_URL to use the database from Tecnico. Note that you need to replace istxxxxxx and pgpass using your information.

   heroku config:set DATABASE_URL='postgres://istxxxxxx:[email protected]/istxxxxxx'

7. Are you ready for our first deploy?

   git push heroku main

   Take notice of the output of the previous command. It should tell you whether the app was successfuly deployed or not. Congratulations!

   Note: You might need to delete the file fly.toml.

8. Open the appname index page at https://appname.herokuapps.com/