[Freeipa-devel] [RFC] Serving legacy systems cliens for trusts

Fri May 31 13:29:22 UTC 2013

On Fri, 2013-05-31 at 10:54 +0300, Alexander Bokovoy wrote:
> On Thu, 30 May 2013, Dmitri Pal wrote:
> >[...]
> >>>>
> >>>> For Lunix and older SSSD version we in fact have a problem.
> >>>> What I want to avoid is to have to define procedures and patches for
> >>>> all
> >>>                ^^^^^^ ?
> >>>> the clients. However if you use ipa-client-install it would configure
> >>>> sssd the old way.
> >>>> How to make it configured the new way? Manually? This is error prone
> >>>> and
> >>>> people will be reluctant to reconfigure SSSD. Automatically? Means
> >>>> patches to all the versions of the clients.
> >>>> How we are going to deal with the huge test matrix?
> >>>
> >>> I think rolling out patches to old sssd versions is not a good idea and
> >>> I think we won't have the time to prepare all the needed patches in a
> >>> reasonable time-frame.
> >>>
> >>> For SSSD versions which do not allow multiple search bases (1.5 and 1.6)
> >>> I would suggest to add a new domain section for the AD user with LDAP
> >>> and Kerberos provider. This would allow IPA users to works as before and
> >>> add the AD users to the client. Maybe this would also be a better
> >>> solution for the other SSSD versions instead of multiple search bases,
> >>> at least it's a solution for all versions.
> >>>
> >>> Since we have the python config API for SSSD the needed changes to the
> >>> sssd.conf might be scriptable with a reasonable effort. Maybe this can
> >>> be added to ipa-client-install with a new option like
> >>> --enable-legacy-trust-support which can add the news section to existing
> >>> configuration or include it for new installations?
> >> Bigger question is what is simpler: write configuration instructions or
> >> modify/provide additional script for old SSSD?
> >>
> >> Remeber that trusts with AD are most likely established when IPA clients
> >> are already rolled out. Changing ipa-client-install is not helpful for
> >> this case since the clients are already there.
> >>
> >> Perhaps a better approach would be documentation for non-SSSD case and a
> >> simple snippet that can be run alone or in use with puppet/etc to deploy
> >> massively. The snippet would use SSSDConfig Python API to add needed
> >> modifications to the clients' SSSD configuration.
> >>
> >> We can even extend IPA server tools to allow generating such snippets
> >> based on the trusts configuration. After all, we do have control over
> >> IPA server in such cases.
> >>
> >>
> >> I have updated wiki page with discussed ideas.
> >
> >Sorry but this is not enough.
> >I do not see a discussion the design about the client side solutuon
> >procedure.
> >
> >I am looking for a session that would contain a table (or like):
> >
> >--------------------------------------------------------------------------
> >|   Type/Version of the client   | Action                                |
> >--------------------------------------------------------------------------
> >| Solaris/HP-UX/AIX (non sssd)   | Configure manually to recognize AD as |
> >|                                | a domain following following steps ...|
> >--------------------------------------------------------------------------
> >| Clients that have SSSD         | If the client is already installed    |
> >| before 1.9                     | and configured do X                   |
> >|                                | If it is a fresh install of the       |
> >|                                | client do Y                           |
> >--------------------------------------------------------------------------
> >| SSSD 1.9 and later             | Use the following ipa-client-install  |
> >|                                | flags XYZ and/or authconfig command   |
> >|                                | ABC                                   |
> >--------------------------------------------------------------------------
> >
> >Can something like this be added to wiki and corresponding tickets to provide a testable
> >replacements for XYZ above be filed in trac?
> I've added more, including three tickets to cover specific
> configurations.
> 
> Unfortunately, we have limits in multiple search bases approach by
> the commercial UNIX vendors since their LDAP modules do not support
> multiple search bases. For all of those platforms there is PADL pam_ldap
> available which can be used for the same purpose.
> 
> If we still want to support native pam_ldap on Solaris (which don't work
> with multiple search bases), we'd have to merge LDAP trees.

Alexander, in my initial proposal I said that trusted users should be
put in the same tree as compat users, it was exactly to address this
problem.

We do not need to cause more problems by using multiple search trees
IMO.

Simo.

> #3670 [RFE] tool to create configurations for old legacy clients for trusts
> https://fedorahosted.org/freeipa/ticket/3670
> 
> #3671 add support for SSSD 1.5-1.8 configurations to ipa-advise-client
> https://fedorahosted.org/freeipa/ticket/3671
> 
> #3672 add support for PADL pam_ldap/nss_ldap configurations to ipa-advise-client
> https://fedorahosted.org/freeipa/ticket/3672
> 
> ipa-advise-client tool would look up existing IPA server configuration
> and decide how should look sample configuration for the specified case.
> It will generate a script that will output needed configuration files
> (or their snippets) or commands that should be executed on the client
> side.
> 
> The reason for this indirection is to allow greater flexibility in
> future, like being able to check PAM configuration at the client side
> before recommending changes (or run authconfig).
> 
> 

-- 
Simo Sorce * Red Hat, Inc * New York