[Freeipa-devel] [PATCH] 0077 Check direct/reverse hostname/address resolution in ipa-replica-install

[Rob Crittenden]

Petr Viktorin wrote:
> On 09/14/2012 08:46 AM, Martin Kosek wrote:
>> On 09/13/2012 10:35 PM, Rob Crittenden wrote:
>>> Petr Viktorin wrote:
>>>> On 09/11/2012 11:05 PM, Rob Crittenden wrote:
>>>>> Petr Viktorin wrote:
>>>>>> On 09/04/2012 07:44 PM, Rob Crittenden wrote:
>>>>>>> Petr Viktorin wrote:
>>>>>>>>
>>>>>>>> https://fedorahosted.org/freeipa/ticket/2845
>>>>>>>
>>>>>>> Shouldn't this also call verify_fqdn() on the local hostname and not
>>>>>>> just the master? I think this would eventually fail in the conncheck
>>>>>>> but
>>>>>>> what if that was skipped?
>>>>>>>
>>>>>>> rob
>>>>>>
>>>>>> A few lines above there is a call to get_host_name, which will call
>>>>>> verify_fqdn.
>>>>>>
>>>>>
>>>>> I double-checked this, it fails in conncheck. Here are my steps:
>>>>>
>>>>> # ipa-server-install --setup-dns
>>>>> # ipa-replica-prepare replica.example.com --ip-address=192.168.100.2
>>>>> # ipa host-del replica.example.com
>>>>>
>>>>> On replica, set DNS to IPA master, with hostname in /etc/hosts.
>>>>>
>>>>> # ipa-replica-install ...
>>>>>
>>>>> The verify_fqdn() passes because the resolver uses /etc/hosts.
>>>>>
>>>>> The conncheck fails:
>>>>>
>>>>> Execute check on remote master
>>>>> Check connection from master to remote replica 'replica.example.com':
>>>>>
>>>>> Remote master check failed with following error message(s):
>>>>> Could not chdir to home directory /home/admin: No such file or
>>>>> directory
>>>>> Port check failed! Unable to resolve host name 'replica.example.com'
>>>>>
>>>>> Connection check failed!
>>>>> Please fix your network settings according to error messages above.
>>>>> If the check results are not valid it can be skipped with
>>>>> --skip-conncheck parameter.
>>>>>
>>>>> The DNS test happens much further after this, and I get why, I just
>>>>> don't see how useful it is unless the --skip-conncheck is used.
>>>>
>>>> For the record, it's because we need to check if the host has DNS
>>>> installed. We need a LDAP connection to check this.
>>>>
>>>>> ipa-replica-install ~rcrit/replica-info-replica.example.com.gpg
>>>>> --skip-conncheck
>>>>> Directory Manager (existing master) password:
>>>>>
>>>>> ipa         : ERROR    Could not resolve hostname replica.example.com
>>>>> using DNS. Clients may not function properly. Please check your DNS
>>>>> setup. (Note that this check queries IPA DNS directly and ignores
>>>>> /etc/hosts.)
>>>>> Continue? [no]:
>>>>>
>>>>> So I guess, what are the intentions here? It is certainly better than
>>>>> before.
>>>>>
>>>>> rob
>>>>
>>>> If the replica is in the master's /etc/hosts, but not in DNS, the
>>>> conncheck will succeed. This check explicitly queries IPA records only
>>>> and ignores /etc/hosts so it'll notice this case and warn.
>>>>
>>>
>>> Ok, like I said, this is better than we have. Just one nit then you
>>> get an ack:
>>>
>>> +        # If remote host has DNS, check forward/reverse resolution
>>> +        try:
>>> +            entry = conn.find_entries(u'cn=dns',
>>> base_dn=DN(api.env.basedn))
>>> +        except errors.NotFound:
>>>
>>> u'cn=dns' should be str(constants.container_dns).
>>>
>>> rob
>>
>> This is a search filter, Petr could use the one I already have in
>> "dns.py::get_dns_masters()" function:
>> '(&(objectClass=ipaConfigObject)(cn=DNS))'
>>
>> For performance sake, I would also not search in the entire tree, but
>> limit the
>> search only to:
>>
>> DN(('cn', 'masters'), ('cn', 'ipa'), ('cn', 'etc'), api.env.basedn)
>>
>> Martin
>>
>
> Attaching updated patch with Martin's suggestions.

I think what Martin had in mind was:

if api.Object.dnsrecord.get_dns_masters():
     ...