[Samba] RHEL7/Centos7 with Samba AD

[vincent at cojot.name]

Hi All,

I know RHEL has bad press here but I'd like to share a different opinion 
(works for me) and maybe share some of my settings.
BTW, Those views are my own, not those of my employer.

I run a small AD at home. The setup is as follows:
- two AD DCs (RHEL7.6 KVM virtual machines + Samba 4.8.7 rpms based on 
SPECs from TranquilIT/Fedora).
- several Win10 laptops joined to the domain.
- several RHEL7.6 clients/Machines running 'realmd' and joined to the 
domain. The AD users can log into those machines and their Linux account 
gets mapped appropriately.

I set policies from a Win10 VM using RSAT and since there is a lot of 
litterature on the excellent Samba wiki and on the net, this wasn't too 
difficult for the Win* noob in me.

It's been running great so far but because I'm rebuilding the rpms myself 
and actually using 'realmd' I feel a little like I am in uncharted 
territory. At least, the RHEL7 part is familiar to me. :)

First, I needed to make a few changes to the client Linux systems: 
a slightly modified krb5 client config and a custom sssd config once they 
were joined ('realm join ...') to the AD domain.

The most important part was that the RHEL7 hosts wouldn't be heavily 
modified, except for the two AD DCs which run a custom build of Samba, of 
course.

For sssd, I used the following (customized file):
------------------------------------------------------
[sssd]
domains = ad.lasthome.solace.krynn
config_file_version = 2
services = nss, pam, pac

[domain/ad.lasthome.solace.krynn]
id_provider = ad
auth_provider = ad
access_provider = ad
chpass_provider = ad

ad_gpo_access_control = disabled
override_gid = 100

ad_domain = ad.lasthome.solace.krynn
krb5_realm = AD.LASTHOME.SOLACE.KRYNN
realmd_tags = manages-system joined-with-samba

#
cache_credentials = True
krb5_store_password_if_offline = True
ldap_id_mapping = False
use_fully_qualified_names = False
default_shell = /bin/bash
fallback_homedir = /export/home/%u@%d
ldap_referrals = False
ignore_group_members = True

[nss]

[pam]
------------------------------------------------------

For realmd, it was only a matter of following the documentation, which 
resulted in
# realm join --automatic-id-mapping=no ad.lasthome.solace.krynn -U administrator
[...]
# realm list
ad.lasthome.solace.krynn
   type: kerberos
   realm-name: AD.LASTHOME.SOLACE.KRYNN
   domain-name: ad.lasthome.solace.krynn
   configured: kerberos-member
   server-software: active-directory
   client-software: sssd
   required-package: oddjob
   required-package: oddjob-mkhomedir
   required-package: sssd
   required-package: adcli
   required-package: samba-common-tools
   login-formats: %U
   login-policy: allow-realm-logins

So, IMHO RHEL7/Centos7 does just fine in a Samba AD/DC setup either as 
clients or DCs. I still have a few details to work out (how to move the 
Samba servers from local auth to AD auth, etc.. mostly because it's not 
my area of expertise) but it's been working fine for me so far.

The only area of concern on el7 is to find a -reliable- Samba RPM builder 
for el7. So far, I've tried:

- TranquilIT - https://dev.tranquil.it/wiki/Samba4
Their latest 4.8.x rpms are stuck on 4.8.5 and they don't provide 
source rpms unless you complain a lot.

- http://azzurro.ezplanet.net : Seems pretty much out of updates

- http://wing-net.ddo.jp/wing : Web page still up but I've been unable to 
pull down rpms from them for months.

Any non-inflamatory comments are welcome! :)

Vincent