How can I host more than 1 Discourse forum on 1 VPS?

You have two options:

  • Multisite - more complicated Multisite configuration with Docker
  • Multiple containers - slightly complicated (requires a reverse proxy etc as mentioned above), more expensive.
    Follow the instructions for setting up Discourse without the ./discourse-setup script (cp samples/standalone.yml containers/app2.yml) and rename the volumes to something other than standalone.