[wildfly-dev] Do we support overlay for files in jar of war of ear?

[Lin Gao]

Hi Richard,

  Thank you for the reply. :-)

> our current 'Overlay feature" implementation is quite limited to be honest.
> It is not possible to introduce new files inside jar inside war that is in
> ear.
> The only exception is if war is exploded inside ear.

  I don't think there is any difference on exploded or not of war from structure
POV(in case of war inside ear), EarStructureProcessor[1] will explode the war if
the war is a file inside ear, and will copy it to temporary directory if it is a
directory inside ear.

> Further more it is not possible to overlay static content inside wars
> (although Wildfly documentation for overlays feature promises that).
> The reason is every war is exploded to temporary location during
> the deploy process and
> 
> org.wildfly.extension.undertow.deployment.ServletResourceManager
> 
> obtains physical location of that exploded archive and passes it to
> FileResourceManager / PathResourceManager in its constructor.
> 
> This at first sight innocent hack bypasses all VFS modifications.
> So although you would mount war static files properly via overlays,
> those overlays will be completely ignored.
> The only exception are deployment descriptors,
> which are processed during the deployment phase.
> 
> Note: Don't get confused with overlays in ServletResourceManager.
> Those are Undertow specific and have nothing to do with WildfFly deployment
> overlays.

  Actually it can overlay static content within WAR, the DeploymentOverlayDeploymentUnitProcessor[2]
will replace the file in the exploded temporary directory with the content user wants to overlay.


> In order to fix your concrete problem (i.e. adding new file inside
> jar in war in ear) I'd guess fixing just DeploymentOverlay processors will be
> insufficient.
> With high probability you'll need to revisit also
> WarDeploymentStructureProcessor.

  Yeah, I thought it too, but it will require WarStructureDeploymentProcessor to access its parent
DeploymentUnit's attachment for deferred overlays, even deferred after
DeferredDeploymentOverlayDeploymentUnitProcessor for the top level EAR deployment, I don't
know whether it is correct way to do this. :-)

> Good news is 'Wildfly Deployment Overlays' should work without any
> limitations in
> upcomming Wildfly 11. There's a PR eliminating Wildfly dependency on JBoss
> VFS:
> 
> https://github.com/wildfly/wildfly-core/pull/1261
> 
> The PR incorporates 'Deployment Overlay' complete rewrite with no limitations
> current implementation has.

  Hope it can resolve all overlay related issues. :-)

  Since the PR to remove VFS is up, I think my PRs[3] won't get merged any way.

  But 2 downstream product issues[4] depend on this, so I will keep the my PRs open,
if we can leave the overlay for files in jar of war inside ear, could you please
review the PRs in [3] to see whether it is OK? Thanks!~ :-)

[1] https://github.com/wildfly/wildfly/blob/master/ee/src/main/java/org/jboss/as/ee/structure/EarStructureProcessor.java#L271
[2] https://github.com/wildfly/wildfly-core/blob/master/server/src/main/java/org/jboss/as/server/deployment/DeploymentOverlayDeploymentUnitProcessor.java#L111-L112
[3] https://github.com/wildfly/wildfly-core/pull/1332 and https://github.com/wildfly/wildfly/pull/8528
[4] https://bugzilla.redhat.com/show_bug.cgi?id=1147352 and https://issues.jboss.org/browse/JBEAP-2491

Best Regards
--
Lin Gao
JBoss Software Engineer


> On 12/23/2015 05:17 PM, Lin Gao wrote:
> 
> 
> 
> Hi,
> 
> I am working on https://issues.jboss.org/browse/WFCORE-761 for a while, and I
> am stuck in the case of overlaying files in jar of war of ear.
> 
> I want to know that do we support overlay for files in jar of war of ear?
> like: xx.ear/yy.war/zz.jar/META-INF/config.properties
> 
> DeploymentOverlayDeploymentUnitProcessor.java[1] and
> DeferredDeploymentOverlayDeploymentUnitProcessor.java[2] are classes to
> handle the deployment overlay, but in this case, the jar of war of ear does
> not get mounted yet, which leads to
> DeferredDeploymentOverlayDeploymentUnitProcessor.handleEntryWithFileParent()
> method is called, which just prints the error message.
> 
> The way to fix it maybe mount the jar(VFS.mountZip) beforehand, but it is
> specific to the case of ear/war/jar, and these 2 classes are more
> generic(they are in wildfly-core, no ee nor undertow extension), so where
> this can be fixed?
> 
> [1]
> https://github.com/wildfly/wildfly-core/blob/master/server/src/main/java/org/jboss/as/server/deployment/DeploymentOverlayDeploymentUnitProcessor.java
> [2]
> https://github.com/wildfly/wildfly-core/blob/master/server/src/main/java/org/jboss/as/server/deployment/DeferredDeploymentOverlayDeploymentUnitProcessor.java
> 
> Best Regards
> --
> Lin Gao
> JBoss Software Engineer
> 
> 
> 
> _______________________________________________
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> 
> --
> Richard Opalka
> Principal Software Engineer
> JBoss by Red Hat
> Mobile: +420 731 186 942
> 
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