[Freeipa-devel] [PATCH] 888 always verify hostname

[Martin Kosek]

On Fri, 2011-10-07 at 08:58 -0400, Rob Crittenden wrote:
> Martin Kosek wrote:
> > On Thu, 2011-10-06 at 22:59 -0400, Rob Crittenden wrote:
> >> When installing with DNS we skip a few hostname checks on the assumption
> >> that the DNS we are installing will cover things. We still need to
> >> verify /etc/hosts and we do this with gethostbyname_ex() which returns
> >> the primary name and all other names of the host. If the primary name
> >> doesn't match (e.g. the shortname is defined first in /etc/hosts) or it
> >> isn't resolvable at all then we error out.
> >>
> >> This also prevents a chicken-and-egg error as several services need to
> >> start before DNS is available so the hostname must be defined.
> >>
> >> rob
> >
> > I see several problems with the patch. At first, it needs a rebase, I
> > reworked the exceptions raised in verify_fqdn in #1899.
> >
> > Then, this patch would break several things:
> >
> > 1) Now, when we install a server with --setup-dns and the host is not
> > resolvable, we add a record to /etc/hosts ourselves, so that the user is
> > not obliged to hack /etc/hosts:
> >
> > # ipa-server-install --setup-dns
> > ...
> > Server host name [vm-050.idm.lab.bos.redhat.com]:
> >
> > Warning: skipping DNS resolution of host vm-050.idm.lab.bos.redhat.com
> > The domain name has been calculated based on the host name.
> >
> > Please confirm the domain name [idm.lab.bos.redhat.com]:
> >
> > Unable to resolve IP address for host name
> > Please provide the IP address to be used for this host name: 10.16.78.50
> > Adding [10.16.78.50 vm-050.idm.lab.bos.redhat.com] to your /etc/hosts file<<<<<<
> > The IPA Master Server will be configured with
> > Hostname:    vm-050.idm.lab.bos.redhat.com
> > IP address:  10.16.78.50
> > Domain name: idm.lab.bos.redhat.com
> 
> Yes but the entry is added /etc/hosts at the very END of installation, 
> apparently too late for some things. We can alternately add this prior 
> to configuring anything else.

But we add the entry to /etc/hosts right in the beginning. After the
line marked with <<<<<< is printed. I double-checked it right now.

> 
> >
> >
> > 2) This will break ipa-replica-prepare. We cannot assume that only local
> > host names are passed to to verify_fqdn since it is also used to for new
> > replica hostname check in ipa-replica-prepare:
> >
> > # ipa-replica-prepare vm-103.idm.lab.bos.redhat.com
> > Directory Manager (existing master) password:
> >
> > The host name vm-103.idm.lab.bos.redhat.com is not resolvable. It must
> > appear in at least /etc/hosts.
> > Add the --ip-address argument to create a DNS entry.
> >
> > We must be very cautious in this function, there was already a BZ from
> > RHEV-M guys which could be now broken:
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=729357
> >
> > Martin
> >
> 
> Ok, perhaps it just needs to be pulled directly into ipa-server-install. 
> We do need some mechanism to check /etc/hosts to be sure that there 
> isn't an existing bad host entry.
> 
> rob

Please check the patch I sent. I do one part in verify_fqdn and one part
in ipa-server-install when user gives us an address.

Martin