Set up a multisite development environment

It's possible to run discourse in multisite mode in development. A multisite server uses a different DB and hostname for each site that it serves. This is useful if you are developing a feature or a plugin that should be multisite compatible.

All you need to do is add an appropriate config/multisite.yml file. i.e:

---
alternate:
  adapter: postgresql
  database: discourse_alternate
  host_names:
    - alternate.localhost

To run rake tasks against these extra sites, simply add the RAILS_DB environment variable with the name of the site that you are targeting:

RAILS_DB=alternate rake db:create
RAILS_DB=alternate rake db:migrate

Some rake tasks are special in that, when RAILS_DB isn't specified in development, they run across all sites:

rake db:create
rake db:migrate

In general, however, running rake tasks without RAILS_DB set will target the default site.

To access the site, start the dev server:

bin/dev

You may now be able to view the your new site at http://alternate.localhost:3000, but if you cannot, you may need to add alternate.localhost to your /etc/hosts file or equivalent.