Ubuntu – Single sign on with Apache and LDAP

apache-2.4authenticationhttp-authenticationsingle-sign-onUbuntu

I have a server running two web applications: Gerrit and Mantis BT. Now, these applications connect to an LDAP server to authenticate users and it works fine. But the user has to authenticate for each application; I would like to allow the user to authenticate only once (possibly using Apache+LDAP) and reuse the credentials to automatically login the user in both applications.

My network architecture now:

diagram of network architecture I have now

The network architecture I want:

diagram of network architecture I want

I don't even know what to look for on Google as I am not familiar with HTTP authentication and server administration in general. Any solution or pointers toward what I want would be appreciated.

Configuration:
Ubuntu server 14.04 LTS
Apache2 2.4
Gerrit 2.10
Mantis BT 1.2.19

Important notes:
I want to keep Gerrit.
I can use another bug tracker if it does what I want easily.

Best Answer

There are several standards for web SSO. LDAP is not an SSO mechanism, just information lookup. Reach out to your vendors to find out if these applications support Kerberos (Apache uses mod_auth_kerb) or SAML (such as Shibboleth). Each will require some infrastructure, such as Active Directory, FreeIPA, Shibboleth, Oracle Identity Federation, etc.