This docker container can be used to make a website available via onion service on Heroku.
To find out how to use containers on Heroku please check:
https://devcenter.heroku.com/articles/container-registry-and-runtime
To deploy this container please run:
$ heroku container:push web -a <app-id>
$ heroku container:release web -a <app-id>
You can open your app on the clear web and you will find the address to the onion service.
There are things that might still go wrong and have not been tested.