Defining a new interface

[Torsten Schlabach]

Dear Juju experts!

We are in the process to write some charms which we will need for our services. Part of that involves LDAP. So we think we should create an LDAP server charm and then have a couple of other charms which install services which require an LDAP server connection. So this is pretty similar to the concept of deploying MySQL using the MySQL charm, then deploying for example Drupal which connects to MySQL.

Now obviously there is a concept of interfaces in Juju, possibly with some inheritance, i.e. there is a db interface with a subclass of MySQL which obviously defined that for a MySQL connection one needs four parameters (server IP, database name, username and password).

Now we wonder if there is already a db:ldap interface. We couldn't spot one, actually. We also wonder if we shall treat LDAP as a subtype of db or independently.

But we wonder the most where and how those classes are defined / documented and how we could implement our own class. We may also need some additional interface later, such as mail:imap or smtp for example.

Any pointers are welcome.

Kind regards,
Torsten