[Freeipa-devel] [PATCH 0104] do not disconnect when using existing connection to check default CA ACLs

[Jan Cholasta]

On 25.11.2015 09:28, Martin Babinsky wrote:
> On 11/25/2015 07:21 AM, Jan Cholasta wrote:
>> On 25.11.2015 05:56, Fraser Tweedale wrote:
>>> On Tue, Nov 24, 2015 at 05:38:45PM +0100, Jan Cholasta wrote:
>>>> On 24.11.2015 17:17, Martin Babinsky wrote:
>>>>> On 11/24/2015 05:10 PM, Martin Babinsky wrote:
>>>>>> On 11/24/2015 05:01 PM, Martin Babinsky wrote:
>>>>>>> On 11/24/2015 04:58 PM, Jan Cholasta wrote:
>>>>>>>> On 24.11.2015 16:48, Martin Babinsky wrote:
>>>>>>>>> On 11/24/2015 04:44 PM, Martin Babinsky wrote:
>>>>>>>>>> https://fedorahosted.org/freeipa/ticket/5459
>>>>>>>>>>
>>>>>>>>> forgot to attach the actual file *slaps himself*
>>>>>>>>
>>>>>>>> ipaserver/install/cainstance.py:1849: [E1101(no-member),
>>>>>>>> ensure_default_caacl] Instance of 'API' has no 'Backed' member)
>>>>>>>>
>>>>>>>
>>>>>>> Fixed
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> Also attaching rebased patch for ipa-4-2
>>>>>>
>>>>>>
>>>>>>
>>>>> Ignore the rebased patch, the original 104.1 applies on 4-2 just fine.
>>>>
>>>> Thanks, ACK.
>>>>
>>>> Pushed to:
>>>> master: ed830af693c596b286b30959eb3166b59cc030c6
>>>> ipa-4-2: c5faaede276f3052517ddf86e64cb228e95dca2a
>>>>
>>> Thanks for anaysing and fixing these connection issues which were
>>> presumably introduced by my patches.  I did not hit these in my
>>> testing.  Admittedly I was focused on the ipa-4-2 branch and my
>>> testing was mainly done there.
>>>
>>> Brittle LDAP connection logic in install and upgrade is an ongoing
>>> problem.  What shall we do to improve the situation?  Push
>>> connection details into the Backend and let it connect if/when
>>> needed, rather than managing connection state from the outside?
>>>
>>> I filed a ticket: https://fedorahosted.org/freeipa/ticket/5491
>>
>> I don't think we need to be smart about it, everyone just needs to make
>> sure that when an ad-hoc connection is opened somewhere, it is also
>> closed in the same place. The same applies for any other resource.
>>
>>>
>>> Thanks,
>>> Fraser
>>>
>>
>>
>
> Maybe it would be a good idea to implement some decorator/context
> manager to connect/disconnect from specified connection and wrap the
> CRUD code. Example usage:
>
> """
> decorator:
> @connected(api.Backend.ldap2, ldapi=True)
> def do_magic(api, *args, **kwargs):
>     # do stuff
>
> context manager:
>
> with connected(api.Backend.ldap2, ccache=example_ccache):
>      do_some_other_magic()
> """
>
> I remember Jan having some objections against this so it would be nice
> to hear why this is not a good idea.

a) For ad-hoc connection objects, LDAPClient should be used instead of 
ldap2. It already supports the context manager protocol:

     with LDAPClient(uri) as conn:
         conn.gssapi_bind()
         ...

b) The api.Backend.ldap2 object should be connected and disconnected 
exactly once per api object per command. This is not done ATM and the 
usual workaround is to connect it manually, which has lead to the mess 
we have now.

Also, only GSSAPI authentication with valid IPA user credentials should 
be used with ldap2, even for ldapi connections.

-- 
Jan Cholasta