Steps to Upgrade a Heroku DB in a script

upgrade_db.sh

#!/usr/bin/env bash

# https://devcenter.heroku.com/articles/updating-heroku-postgres-databases#updating-with-follower-changeover

APP=name-production # name-staging

heroku addons:create heroku-postgresql:standard-2 --follow DATABASE_URL --app $APP        # DONE
heroku addons:wait                                                                        # DONE
for (( ; ; )); do; heroku pg:info --app $APP | grep Behind; sleep 1; done                 # DONE

heroku maintenance:on --app $APP

heroku ps:scale worker=0 --app $APP

heroku pg:info --app $APP

heroku pg:unfollow DATABASE_URL --app $APP

heroku pg:promote HEROKU_POSTGRESQL_TEAL_URL --app $APP

heroku ps:scale worker=1 --app $APP
heroku maintenance:off --app $APP


heroku addons:destroy HEROKU_POSTGRESQL_ORANGE_URL
heroku addons:destroy HEROKU_POSTGRESQL_SILVER_URL