[Samba] samba4 kerberized nfs4 with sssd ad client

Robert Marcano robert at marcanoonline.com
Fri Jul 24 15:08:46 UTC 2020

On 7/24/20 10:53 AM, Rowland penny via samba wrote:
> On 24/07/2020 15:45, Jason Keltz via samba wrote:
>> On 7/24/2020 7:25 AM, Peter Milesson via samba wrote:
>>> On 2020-07-24 12:57, Jason Keltz via samba wrote:
>>>> Hi Rowland,
>>>> In effect, I'm still using Samba on the DC, which is why I still 
>>>> thought this was relevant on the mailing list. :)
>>>> The reason in particular that I was looking at sssd client as 
>>>> opposed to winbind was that  we are running CentOS 7. I know if I 
>>>> want to use the latest Samba 4.12 on the clients, I'll have problems 
>>>> with gnutls because it's outdated in CentOS 7. Yes, someone has 
>>>> figured out a way around that by compiling a separate gnutls, but 
>>>> I'm just not 100% comfortable with that. It's still an option.  The 
>>>> problem is that if I spend my days figuring out how to upgrade 
>>>> hundreds of custom CentOS machines from 7 to 8 (which I will no 
>>>> doubt eventually do) then I won't have time to figure out 
>>>> integration of this domain into AD. If I start with AD then I can't 
>>>> really use the latest  4.12. maybe that's fine because eventually we 
>>>> will move to CentOS 8. However, what if a later Samba version 
>>>> requires  an even later version of  gnutls that CentOS 8 doesn't run 
>>>> with in the future!  Then I'll again be stuck in this position and 
>>>> may have to upgrade the OS clients to use the later Samba. There's al
>>>>   ways going to be this chicken and egg problem of course. That's 
>>>> just the environment we work in. That's why I was hoping that if I 
>>>> used SSSD then I could somewhat punt the problem . As long as the 
>>>> main DC was running the latest OS and could run the latest Samba 
>>>> then the clients could use their SSSD to connect. In addition, the 
>>>> SSSD configuration for AD is so trivial.  The winbind configuration, 
>>>> I have tested and it works but it's definately more complex. I have 
>>>> to see whether it handles token groups because the SSSD 
>>>> configuration without token groups was very slow using SSSD because 
>>>> of the number of groups.  I'm not fixed at using sssd but just 
>>>> thinking about all the options. There are always many ways to solve 
>>>> the same problem. :)
>>>> Jason.
>>>> On Jul. 24, 2020, 2:22 a.m., at 2:22 a.m., Rowland penny via samba 
>>>> <samba at lists.samba.org> wrote:
>>>>> On 24/07/2020 03:42, Jason Keltz via samba wrote:
>>>>>> Hi everyone,
>>>>>> I have a samba DC, let's call it dc1.ad.example.com.
>>>>>> I have two members of the domain - server1.ad.example.com and
>>>>>> server2.ad.example.com.   They are not running smbd and winbind.
>>>>>> Instead, they are running SSSD with AD backend.
>>>>> Sorry Jason, wrong mailing list, we do not produce sssd, so cannot
>>>>> support it, because we know very little about it. I suggest you try 
>>>>> the
>>>>> sssd-users mailing list.
>>>>> If you want to use Samba instead, I am more than willing to help you
>>>>> with this, it is very easy and there is the bonus of being able to
>>>>> share
>>>>> files.
>>>>> Rowland
>>>>> -- 
>>>>> To unsubscribe from this list go to the following URL and read the
>>>>> instructions:  https://lists.samba.org/mailman/options/samba
>>> Hi Jason,
>>> I have got a few CentOS servers as Samba AD members. I found out that 
>>> upgrading them to CentOS 8 isn't worth the hazzle, a completely 
>>> different paradigm, and lots of migration issues to solve. As you 
>>> have got lots of machines, it could probably pay off to create your 
>>> own solution, but in your place, I would get nervous that every new 
>>> update would break something.
>>> I'm going to migrate my few servers to Debian Buster instead. It 
>>> seems to be a much less painful way. Up until recently, I have 
>>> exclusively used CentOS, but I have found Debian very capable, and 
>>> not very different to work with, compared to CentOS 7. The updaMIR te 
>>> policy is also fairly conservative.
>>> Just my five cents...
>>> Best regards,
>>> Peter 
>> Hi Peter,
>> Our client systems need to continue to run CentOS because a variety of 
>> software that we use requires CentOS/RHEL.  Some of the software is 
>> very version specific.  I can't even upgrade to CentOS 8 until certain 
>> software is compatible with 8.  Running a separate Linux distribution 
>> on the servers and the clients is possible, of course, but in a small 
>> team, just a headache to handle multiple OS paths.   If we were a 
>> bigger team, this is definately something I would consider though.
>> Jason.
> Rule one: Never run software that is tied to a specific OS, you get 
> trapped, as you have found. If some entity tries selling you software 
> that requires a specific OS (and worse a specific version), tell them to 
> **** off.
> Just what are these 'softwares' that require Centos ?
> Rowland

I usually avoid threads where someone mentions SSSD because they always 
end the same way. The original poster is asking a question about using a 
Samba DC server using winbind at the server and his problems our doubts 
about the using the Kerberos part of Samba AD, and the discussion goes 
down to SSSD no no no, change OS, etc. A user asking with problems with 
a Mac or Windows client doesn't get that kind of responses, clients more 
closed that anything Red Hat produces.

The initial response that asking on the SSSD mailing list would be a 
better idea was probably the good end of it if no other person was able 
to help.

I personally can't help, because I use FreeIPA for my Linux clients and 
Samba AD for Windows clients, establishing a trust between domains. I 
have done long ago the other way of the original poster problem, NFS 
Kerberized NFS shares from a domain using MIT Kerberos (via FreeIPA), 
shares to Windows clients with Samba, but Samba standalone shares, doing 
LDPA integration with FreeIPA 389 server, but I would not recommend that 
now that the AD implementation of Samba is robust enough.

Note: Now that CentOS 8 where mentioned early on the list, CentOS 8 
clients joined to a Samba domain using SSSD works pretty well. Some tips 
at https://lists.samba.org/archive/samba/2020-March/228875.html

More information about the samba mailing list