This is how you start a Discourse stack with Bitnamis compose file and add a plugin to it

add-new-bitnami-discourse-plugins.sh

# if you use https://github.com/bitnami/bitnami-docker-discourse for your Discourse setup
# you can simply add some plugins (https://meta.discourse.org/c/plugin):

# 0) Clone docker-compose.yml
curl -sSL https://raw.githubusercontent.com/bitnami/bitnami-docker-discourse/master/docker-compose.yml > docker-compose.ym

# 1) Start Docker Compose
docker-compose up

# 2) Join container
docker exec -it discourse_discourse_1 bash

# 3) cd into discourse path and execute the following rake tasks:
cd /opt/bitnami/discourse
RAILS_ENV=production bundle exec rake plugin:install repo=https://github.com/discourse/discourse-solved
RAILS_ENV=production bundle exec rake assets:precompile