[Freeipa-devel] [PATCH 0208] Respect --test option in upgrade plugins

[Petr Spacek]

On 13.3.2015 10:42, Alexander Bokovoy wrote:
> On Fri, 13 Mar 2015, Petr Spacek wrote:
>> On 13.3.2015 10:18, Martin Kosek wrote:
>>> On 03/12/2015 05:10 PM, Rob Crittenden wrote:
>>>> Petr Spacek wrote:
>>>>> On 12.3.2015 16:23, Rob Crittenden wrote:
>>>>>> David Kupka wrote:
>>>>>>> On 03/06/2015 06:00 PM, Martin Basti wrote:
>>>>>>>> Upgrade plugins which modify LDAP data directly should not be executed
>>>>>>>> in --test mode.
>>>>>>>>
>>>>>>>> This patch is a workaround, to ensure update with --test option will not
>>>>>>>> modify any LDAP data.
>>>>>>>>
>>>>>>>> https://fedorahosted.org/freeipa/ticket/3448
>>>>>>>>
>>>>>>>> Patch attached.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> Ideally we want to fix all plugins to dry-run the upgrade not just skip
>>>>>>> when there is '--test' option but it is a good first step.
>>>>>>> Works for me, ACK.
>>>>>>>
>>>>>>
>>>>>> I agree that this breaks the spirit of --test and think it should be
>>>>>> fixed before committing.
>>>>>
>>>>> Considering how often is the option is used ... I do not think that this
>>>>> requires 'proper' fix now. It was broken for *years* so this patch is a huge
>>>>> improvement and IMHO should be commited in current form. We can re-visit it
>>>>> later on, open a ticket :-)
>>>>>
>>>>
>>>> No. There is no rush for this, at least not for the promise of a future
>>>> fix that will never come.
>>>
>>> I checked the code and to me, the proper fix looks like instrumenting
>>> ldap.update_entry calls in upgrade plugins with
>>>
>>> if options.test:
>>>    log message
>>> else
>>>    do the update
>>>
>>> right? I see just couple places that would need to be updated:
>>>
>>> $ git grep -E "(ldap|conn).update_entry" ipaserver/install/plugins
>>> ipaserver/install/plugins/dns.py:        ldap.update_entry(container_entry)
>>> ipaserver/install/plugins/fix_replica_agreements.py:
>>> repl.conn.update_entry(replica)
>>> ipaserver/install/plugins/fix_replica_agreements.py:
>>> repl.conn.update_entry(replica)
>>> ipaserver/install/plugins/update_idranges.py: ldap.update_entry(entry)
>>> ipaserver/install/plugins/update_idranges.py: ldap.update_entry(entry)
>>> ipaserver/install/plugins/update_managed_permissions.py:
>>> ldap.update_entry(base_entry)
>>> ipaserver/install/plugins/update_managed_permissions.py:
>>> ldap.update_entry(entry)
>>> ipaserver/install/plugins/update_pacs.py:            ldap.update_entry(entry)
>>> ipaserver/install/plugins/update_referint.py:           
>>> ldap.update_entry(entry)
>>> ipaserver/install/plugins/update_services.py: ldap.update_entry(entry)
>>> ipaserver/install/plugins/update_uniqueness.py:
>>> ldap.update_entry(uid_uniqueness_plugin)
>>>
>>>
>>> So from my POV, very quick fix. In that case, I would also prefer a fix now
>>> than a ticket that would never be done.
>>
>> I really dislike this approach because I consider it flawed by design. Plugin
>> author has to think about it all the time and do not forget to add if
>> otherwise ... too bad.
>>
>> I can see two 'safer' ways to do that:
>> - LDAP transactions :-)
>> - 'mock_writes=True' option in LDAP backend which would print modlists instead
>> of applying them (and return success to the caller).
>>
>> Both cases eliminate the need to scatter 'ifs' all over update plugins and do
>> not add risk of forgetting about one of them when adding/changing plugin code.
> I like idea about mock_writes=True. However, I think we still need to make
> sure plugin writers rely on options.test value to see that we aren't
> going to write the data. The reason for it is that we might get into
> configurations where plugins would be doing updates based on earlier
> performed tasks.  If task configuration is not going to be written, its
> status will never be correct and plugin would get an error.

That is exactly why I mentioned LDAP transactions. There is no other way how
to test complex plugins which actually read own writes (except mocking the
whole LDAP interface somewhere).

-- 
Petr^2 Spacek