I’m using dokku and wanted to install discourse into a dokku managed container. I found this gist describing the process, but discovered a few issues with the approach (mainly around the many manual steps, the user permissions and lack of support for multiple instances.)
So I created a dokku plugin to solve these issues: https://github.com/badsyntax/dokku-discourse.
This plugin allows you to manage multiple discourse instances on your dokku server. Hope you find it useful.