[jboss-as7-dev] problems with deployment overlays and linking

[Brian Stansberry]

Sorry for the slow responses on this thread.

I think we should go with Stuart's approach, particularly if Alexey is 
comfortable that the CLI can support high level commands associated with it.

In-line...

On 8/22/12 8:22 AM, Emanuel Muckenhuber wrote:
>
> My main concern is regarding the domain mode, since the additional
> linking does not seem to be necessary to me and just additional steps
> mgmt clients have to take care of.
>
> Whereas the deployment-scanner is a single client for standalone, which
> is under our control. So i wanted to see if we there is a way we can
> make this work which also satisfies your use cases.
>
> I have two things in mind which i'll try to explain quickly:
>
> 1) you still link the overlays as part of the <deployment />, however
> the deploment-scanner is aware of that and won't remove deployments with
> overlays until you use a specific invalidation marker.
>

This requires that the overlays be controlled by the scanner as well. 
Why? Because we don't persist the model resource for scanner-controlled 
deployments. So if a user linked a non-scanner-controlled overlay to a 
scanner controlled deployment (which seems quite rational if the overlay 
involves some environmental settings that never change), the link 
information will be lost on server reboot.

> 2) use overlay directories - this is more the file based approach, Where
> we just pick the "deployment.name + suffix" for the overlay. So there
> would be an automatic overlay/linking done by the deployment-scanner.
>

Same issue as 1).

> 2.1) the overlay directory could be just a link to a virtual file (a
> shared <deployment-overlay />) [1] - so in this case the overlays are
> managed by the model and are not linked to the deployment lifecycle.
>

I confess I don't understand this. In particular, how does it 
fundamentally differ from what Stuart proposes in terms of how to 
organize the data?

>
> Those are half-backed ideas, not sure if any combination of those would
> work for you or would be really more interesting to the ones actually
> implementing the clients?
>
>
> Emanuel
>
>
> [1]
> <deployment-overlay name="deployment.scanner.overlay" >
>      <overlay path="myApp.war" link="myApp-override" />
>      <overlay path="other.ear" link="other-override" />
> </deployment-overlay>
>
> On 08/22/2012 01:03 AM, Stuart Douglas wrote:
>>
>> So what are we going to do here? Personally I much prefer the idea of having this stored in the model and linking it to a deployment, so the overlay lifecycle is not tied to that of the deployment.
>>
>> Another idea I had is that we could do something like define the overlays at domain level, but then define the links at server group or server level using the same name. basically something like:
>>
>> /deployment-overlay=myOverlay/content=WEB-INF/web.xml
>> /deployment-overlay=myOverlay/content=WEB-INF/ejb-jar.xml
>>
>> /server-group=server-group1/deployment-overlay=myOverlay/deployment=test.war
>> /server-group=server-group1/deployment-overlay=myOverlay/deployment=*.war
>>
>> For standalone they would just be combined, similar to what I had below:
>>
>>
>> /deployment-overlay=myOverlay/content=WEB-INF/web.xml
>> /deployment-overlay=myOverlay/content=WEB-INF/ejb-jar.xml
>> /deployment-overlay=myOverlay/deployment=test.war
>> /deployment-overlay=myOverlay/deployment=*.war
>>
>>
>>
>> Stuart
>>
>> On 17/08/2012, at 11:03 PM, Emanuel Muckenhuber <emuckenh at redhat.com> wrote:
>>
>>>
>>> On 08/17/2012 02:52 AM, Stuart Douglas wrote:
>>>> The big problem with this is that it does not work with the deployment scanner.
>>>>
>>>
>>> Yeah, the deployment-scanner is always a story for itself. However i think we could actually make it persist information and be aware of overlays.
>>>
>>> Having overlays as part of the deployment means the lifecycle is managed together, so the deployment-scanner could define it's own invalidation policy. May it be based on whether the content got removed or we have a specific marker for that.
>>>
>>> We could also think of providing a file-based overlay solution, managed by the deployment scanner only. In the end people use the deployment-scanner for a reason, so perhaps not having to worry about the model or "content" folder could be interesting. This would not even need to access persistent information though. Anyway just some ideas on the side.
>>>
>>>> It also has to be specified on every re-deploy.
>>>
>>> When you do a "remove" and "add" then yes. We do have specific operations to replace the content and redeploy the deployment without removing the information from the model.
>>>
>>>> I think the simplest solution here
>>>> is to just move the links under the deployment-overlays element and loose the
>>>> flexibility to link at different levels. e.g:
>>>>
>>>> /deployment-overlay=myOverlay/deployment=test.war
>>>> /deployment-overlay=myOverlay/deployment=*.jar
>>>>
>>>
>>> Yes, i was not really going for the simplest solution for now - this would most likely would be it :)
>>
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-- 
Brian Stansberry
Principal Software Engineer
JBoss by Red Hat