Convert a Heroku application email into a Heroku owner email.

lookup.py

"""
    heroku-email-lookup
    ~~~~~~~~~~~~~~~~~~~

    Given a text file that contains Heroku app email addresses (one on each
    line), this program will spit out a list of app owner email addresses.

    This is useful for Heroku addon providers (like me) who want to email their
    addon customers.  Because Heroku customers may change their account email
    address from time-to-time, Heroku exposes a special API endpoint that this
    script uses to retrieve the account holder's latest email address -- this
    way you can actually email your Heroku addon customers.

    To run this script, set the necessary global variables below, ensure you are
    using Python 3+, and then run:

        $ pip install requests
        $ python lookup.py <file1.txt> [<file2.txt> <file3.txt> ...]

    Written by Randall Degges (
        https://www.rdegges.com
        r@rdegges.com
        @rdegges
    )
"""


from sys import argv, exit

from requests import get


# Settings
HEROKU_USERNAME = 'your-addon-id'
HEROKU_PASSWORD = 'your-addon-manifest-password'


def get_app_emails(files):
    """
    Given an array of filenames, iterate through these files, and return each
    line (stripped) via a generator.

    :param list files: A list of filenames.
    """
    for file in files:
        for app_email in open(file).readlines():
            yield app_email.strip()


def get_owner_email(app_email):
    """
    Given an app_email, retrieve the owner email from Heroku (if available).

    WARNING: This may quit the program if your credentials are invalid. Better
    to fail immediately than error forever.

    :param str app_email: The application email from Heroku.
    :rtype: str or None
    :returns: The owner email, or None.
    """
    try:
        resp = get('https://api.heroku.com/vendor/apps/{}'.format(app_email), auth=(HEROKU_USERNAME, HEROKU_PASSWORD))
    except KeyboardInterrupt as e:
        print('WARNING: CTRL-C detected from user. Quitting immediately.')
        exit(1)
    except Exception as e:
        print(e)
        return None

    if resp.status_code == 401:
        print('ERROR: Your Heroku credentials are incorrect.')
        print('Your username should be the name of your addon (eg: `heroku-redis`), and your password should be the password specified in your addon manifest.')
        exit(1)

    return resp.json()['owner']['email'] if resp.status_code == 200 else None


if __name__ == '__main__':
    for app_email in get_app_emails(argv[1:]):
        owner_email = get_owner_email(app_email)
        if owner_email:
            print(app_email, owner_email)