Proof of concept, there will be errors, please test! :)
$ sudo docker-compose build
$ sudo docker-compose run discourse bash -c "sleep 3 && rake db:migrate assets:precompile"
Provide some configuration via environment variables in docker-compose.yml:
DISCOURSE_HOSTNAME=
DISCOURSE_SMTP_ADDRESS=
DISCOURSE_SMTP_PORT=587
DISCOURSE_SMTP_USER_NAME=
DISCOURSE_SMTP_PASSWORD=
DISCOURSE_DEVELOPER_EMAILS=
Start Discourse:
$ sudo docker-compose up
$ xdg-open http://localhost:3000/