If you want to use Trac as Single Sign On point for Discourse we’ve developed a plugin that allows you to do this. It’s easily installable and configurable.
After installation simply add the details to you configuration file. For example:
[sso] sso_secret = thisisatestsecret sso_redirect = https://my.discourse.example.com/session/sso_login
And grant the
SSO_LOGIN permission to any user you deem fit
For more information, sources and downloads see: