This is a sample Grails 3 web application but modified a little to be able to generate a runnable war that can run at Heroku.
Steps:
$ git clone <this repo>
$ heroku create
$ heroku addons:create heroku-postgresql
$ git push heroku master
NOTE: You may find that this app fails to start up with in the 60 second boot timeout limit imposed by Heroku. If that's the case, please contact Heroku Support.
After a succesful deploy (remote build and run), the webapp will run at URL: https://.herokuapp.com
To check what happens in remote, use for example this command:
$ heroku logs --tail
Note:
You can work and run with this project in the usual way (run for example with grails run-app), but to do a test build for generating a war compatible with Heroku use
$ gradle stage
and then you can run it in local but in the same way of the Heroku environment with:
$ heroku local
To make changes and put in the app "live", remember to commit them and push to heroku.