Hi Frank,

yes, one of the main requirements I am trying to address is handling adding
duplicate users. Also as I mentioned in my previous mail, we need a way so
that an admin user can see list of people with those who are still in
workflows and not accepted.

Thanks

On Wed, Jul 22, 2015 at 5:37 PM, Frank Leymann <[email protected]> wrote:

> Dear Chamila,
>
> in summary, you are implementing a "pessimistic offline lock", right?
> http://martinfowler.com/eaaCatalog/pessimisticOfflineLock.html
>
>
> Best regards,
> Frank
>
> 2015-07-22 7:23 GMT+02:00 Chamila Wijayarathna <[email protected]>:
>
>> Hi all,
>>
>> Currently we are in the process of implementing Workflow support for user
>> operations in IS 5.1.0. Recently we have identified following issue in the
>> implementation. For the sake of the conversation let’s focus only on
>> workflow support for 'addUser' operation.
>>
>> Usually when a user is added to a user store it will go through following
>> 3 steps.
>>
>>    1.
>>
>>    UserOperationEventListener.doPreAddUser
>>    2.
>>
>>    UserStoreManager.doAddUser
>>    3.
>>
>>    UserOperationEventListener.doPostAddUser
>>
>>
>> Workflow integration for 'addUser' operation is currently implemented as
>> follows. We have implemented a UserOperationEventListner in workflow-mgt
>> component whose 'doPreAddUser' hook is called when a user is added through
>> addUser of the UserStoreManager. Then it will trigger a workflow for this
>> task, save the request data and workflow related metadata in a database
>> table (not in user store, separate table introduced), and then will return
>> false, which will stop the further processing of addUser listeners and the
>> operation itself. When the workflow is completed, in its callback method,
>> it will again call 'addUser' method of UserStoreManager where this time it
>> executes all 3 steps, pre-hooks, operation and post hooks, except for the
>> workflow pre-hook. So user will be added to the user store only when the
>> workflow is completed.
>>
>> We came up with 2 limitations of this approach which needs to be
>> addressed.
>>
>>    1.
>>
>>    When a ‘addUser’ workflow is triggered, it should not be possible to
>>    add another user with same userName. Right now we can’t find this out 
>> until
>>    the second workflow to be approved, tries to insert the user to the
>>    userstore.
>>    2.
>>
>>    Admin user should be able to see the list of users who are in the
>>    queue to be added once the workflows are approved.
>>
>>
>> To overcome these limitations, first we came up with the following
>> approach.
>>
>> When user is added and workflow is started, he should be added to the
>> userStore (so adding new users will be prevented from userStore level and
>> list users is also possible as usual). To do this we have to execute
>> 'doPreAddUser' and 'doAddUser' methods when user is added, but also keep a
>> claim saying he is locked or pending, which will prevent modifications or
>> authentication for the user. However we need to prevent the post listeners
>> from executing because the actual user provisioning is not actually
>> completed. E.g. one of the post listeners we have provisions users to
>> external Identity Providers, which can’t happen until the workflow is
>> approved. Of course we can provision him to external system and in case the
>> workflow is rejected we can deprovision the same user in the callback, but
>> the drawback is between such time the user will be like a valid user in the
>> external system. Then once the workflow is accepted it will unlock user as
>> well as execute doPostAddUser which do the outbound provisioning, etc.
>>
>> Basically what we need is to be able to control the execution of the
>> pre-hooks, operation and post-hooks independently from the rest. But for
>> now we can't implement it in this way, since this needs few API changes in
>> user core, which is in carbon4-kernel and there won't be a release of
>> kernel with API changes before IS 5.1.0 release.
>>
>> So we decided to do this in following way.
>>
>> User addition will remain the same, i.e. user will not be added the
>> userstore until workflow is approved, but using the workflow related
>> metadata table we can cater the 2 requirements stated above. That is
>> identify the conflicting scenarios, e.g. adding users with same username
>> and listing the users that are still under processing.
>>
>> The same scenario can be extended to all other user operations as well,
>> such as addRole, updateRoleListOfUser, etc.
>>
>> Thank You!
>>
>>
>> --
>> *Chamila Dilshan Wijayarathna,*
>> Software Engineer
>> Mobile:(+94)788193620
>> WSO2 Inc., http://wso2.com/
>>
>> _______________________________________________
>> Architecture mailing list
>> [email protected]
>> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>>
>>
>
> _______________________________________________
> Architecture mailing list
> [email protected]
> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>
>


-- 
*Chamila Dilshan Wijayarathna,*
Software Engineer
Mobile:(+94)788193620
WSO2 Inc., http://wso2.com/
_______________________________________________
Architecture mailing list
[email protected]
https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture

Reply via email to