Actually, having no passwords and using a platform which supports integrated authentication (like Windows) is probably the best approach with respect to handling this. The authentication requirements are handled at an infrastructure level, meaning no credentials are kept in source control or on your production web servers.

In fact, none of our web servers carry ANY credentials at all. Our IIS processes run as a specific user and are granted access to resources (message queues, databases etc) as required.

I'm not sure stuff like this is entirely possible on Linux (I haven't tried to be honest), but I assume you can do the equivalent with OpenLDAP / pam_ldap and SELinux.