Heroku shared-database to dev migration helper

migrate.py

#!python
# Run this file to upgrade your shared database to a dev plan.
# Make sure you're using the heroku gem >= 2.30.1
# Usage: python migrate.py
# Follow the interactive prompts.

import sys
import subprocess

def remove_shared_database_after_confirmation(app_name):
    addon_resp = subprocess.check_output(["heroku", "addons"])
    if "shared-database" in addon_resp:
        remove_pg = raw_input("Would you like to remove the shared-database plan? Type 'yes' to remove it: ")
        if remove_pg == "yes":
            print "Removing shared-database...",
            subprocess.check_output(["heroku", "addons:remove", "shared-database", "--confirm", app_name])
            print "done."

def main():
    # Get the app name.
    addon_resp = subprocess.check_output(["heroku", "addons"])
    app_name = addon_resp[4:addon_resp.find(" ", 5)]

    continue_resp = "nope"
    while continue_resp.lower() != "yes":
        continue_resp = raw_input("Detected app '%s'. Is this correct?  Type 'yes' to continue: " % app_name)

    # Confirm that we're using postgres
    database_url = subprocess.check_output(["heroku", "config:get", "DATABASE_URL"])
    if "postgres" not in database_url:
        print "This app is not using postgresql."
        remove_shared_database_after_confirmation(app_name)

        sys.exit("Done. Quitting.")

    print "Adding new database...",
    resp = subprocess.check_output(["heroku", "addons:add", "heroku-postgresql:dev"])
    ATTACH_STR = "Attached as "
    # Returns:
    # Adding heroku-postgresql:dev to blows... done, v87 (free)
    # Attached as HEROKU_POSTGRESQL_GRAY
    # Database has been created and is available
    # heroku-postgresql:dev documentation available at: https://devcenter.heroku.com/articles/heroku-postgresql

    attached_pos = resp.find(ATTACH_STR) + len(ATTACH_STR)
    database_name = resp[attached_pos:resp.find("\n", attached_pos)]
    print "done."

    print "Added new database: %s" % (database_name,)

    print "Backing up old database..."
    try:
        if not "pgbackups" in addon_resp:
            subprocess.call(["heroku", "addons:add", "pgbackups"])
    except:
        pass
    subprocess.check_output(["heroku", "maintenance:on"])
    subprocess.call(["heroku", "pgbackups:capture", "--expire"])
    print "done."

    print "Restoring to new database...",
    subprocess.call(["heroku", "pgbackups:restore", database_name, "--confirm", app_name])
    print "done."

    print "Promoting...",
    subprocess.check_output(["heroku", "pg:promote", database_name])
    print "done."

    print "Turning off maintenance and restarting...",
    subprocess.check_output(["heroku", "maintenance:off"])
    subprocess.check_output(["heroku", "restart"])
    print "done."

    print "Migration complete. Please test your application."
    remove_shared_database_after_confirmation(app_name)

    print "\n\nNow, please run postgres ANALYZE on the database to speed up indexes and query optimization."
    print "heroku pg:psql %s " % database_name
    print "=> ANALYZE;\n\n"

    print "Database migration complete."


if __name__ == "__main__":
    main()