Add Ubuntu SSO support in apps, including Phabricator and Discourse. We might have to maintain some local patches.

here's some more info cobbled together from the previous version of this task:

Ubuntu SSO is an OpenID identity provider (see for example askubuntu.com where you can use Launchpad as your identity). If Phabricator supports openid, you could use that to integrate easily.

It unfortunately doesn't support LDAP, and only supports OAuth1.

Feel free to bzr branch lp:canonical-identity-provider and check out docs/resources/token.txt for info on how to get oauth tokens. This is, for example, the authentication mechanism old versions of Ubuntu
Software Center used. Be warned that oauth support might go away in the future though.

You can also file a bug at https://bugs.launchpad.net/canonical-identity-provider/ to get it to the wider attention of SSO developers, because this address is mainly for login issues and as such.

A post was made on Phabricator's Discourse and they refuse to support OpenID, but there are other OAuth1 providers. Indeed, Phabricator provides documentation on how to make a generic OAuth1 provider.

With Discourse, it looks fairly easy.