The *samba-dc* role now supports joining an existing Active Directory
domain as an additional domain controller. The `samba_is_first_dc` variable
controls whether the machine will be provisioned with a new domain (when
true) or added to an existing domain (when false).
Joining an existing domain naturally requires credentials of a user with
permission to add a new DC, the `samba_dc_join_username` and
`samba_dc_join_password` variables can be used to specify them.
Alternatively, if these variables are not defined, then the process will
attempt to use Kerberos credentials. This would require playbooks to
make a ticket-granting-ticket available somehow, such as by executing
`kinit` prior to applying the *samba-dc* role.
The *samba-dc* role installs Samba on the managed node and configures it
as an Active Directory Domain controller. A custom module,
`samba_domain` handles the provisioning using `samba-tool domain
provision` in an idempotent way.
Dustin