[Freeipa-devel] Proposal: reverse stance on installing CA on new masters

[Simo Sorce]

On Thu, 2015-04-09 at 16:52 -0400, Rob Crittenden wrote:
> Simo Sorce wrote:
> > On Thu, 2015-04-09 at 15:42 -0400, Rob Crittenden wrote:
> >> Petr Vobornik wrote:
> >>> On 04/09/2015 04:05 PM, Rob Crittenden wrote:
> >>>> Right now when a new master is installed it is not configured with a CA
> >>>> unless one passes in --setup-ca (or afterward runs ipa-ca-install).
> >>>>
> >>>> Over and over we've seen people who have multiple masters and a single
> >>>> CA, in some cases that CA machine is gone, leaving the realm with no CA
> >>>> at all.
> >>>>
> >>>> I think this is due to the fact that CA replicas are not created by
> >>>> default and the users are not aware of the implications of a single
> >>>> point-of-failure since things otherwise seem to be working.
> >>>>
> >>>> So perhaps the default should be to install a CA unless the user
> >>>> requests one not be installed. A related task may be to create an
> >>>> uninstaller for just the CA.
> >>>>
> >>>> rob
> >>>>
> >>>
> >>> From a general perspective:
> >>>
> >>> When I hear "replica" it evokes a "clone", something equal/identical.
> >>>
> >>> Based on this, the expected behavior for me would be that:
> >>>
> >>> - if master has DNS and CA, then the new replica would also have DNS and
> >>> CA (without any configuration option needed).
> >>> - if an optional service is missing then replica wouldn't have it as
> >>> well by default
> >>>
> >>> This would required reverse options like: --no-dns.
> >>
> >> Pretty much exactly what I was thinking.
> >>
> >> For the option I think we should go with a more generic --ca, --dns,
> >> with the default value matching what the remote master has configured.
> >>
> >> But that's bike shedding.
> >>
> >> The real question is, what do others think? Is this worth filing a
> >> ticket for? It would be a subtle but significant change. This might tie
> >> in nicely with planned topology management too.
> > 
> > I think I would like to see questions in interactive mode, but not force
> > CA and DNS to be installed just because the other replica has them.
> > 
> > The replica originating machines has more to do with topology (what
> > master you want to replicate off) then features.
> > 
> > So if you are doing an interactive install and the remote replica has CA
> > and DNS features, it may be nice to ask: do you want to setup CA too ?
> > Do you want to setup DNS too ?
> > But not do it by default w/o positive confirmation.
> > Esp for DNS it makes little sense as you need a change in DHCP/other
> > infra for it to be of any use and all data is in LDAP anyway
> > The CA case is a little bit more critical as you noted, but I think
> > nagging in interactive is probably good enough.
> 
> That's why I suggested this be tied to the topology plugin, so the user
> has a chance to massage things afterward in an easy manner.
> 
> A less obtrusive suggestion would be to be to try to count the number of
> CAs and spit out a scary warning if it is just one.

Maybe force CA on if there is only one CA ? (Ie first 2 servers get to
be CAs) then a new CA is force installed only if one of the 2 is
killed ?

Simo.

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