After a deep discussion with Sanne Grinovero about the static modules management in wildfly and about some interesting use cases, we tried to design out an improvement that can help both testers and developers.

- Testing the new version of an existing module or testing its resources/dependencies: Sometimes it would be useful to test the integration of a different version of the new library into wildfly. Let's think about a patched version of hibernate-core or jgroups. This is supposed to be done without embedding the resource into the application, but delegating the library management to wildfly, instead.

- Provisioning the static resources for third party libraries dynamically: They asked me to create a lot of static modules for third party libraries a lot of times. This happens each time (always) a bunch of applications use the same, shared set of third party libraries and, of course, each time a developer avoids bundling the libraries inside the binaries (ear/war). Let's think about apache commons, security libraries, or hadoop client libraries (see my github: https://github.com/andreabattaglia/cloudera-eap-modules, there you can find a huge set of the static modules for wildfly used to connect to hadoop services without need of embedding the jars into the applications binaries). This usecase applies to the jdbc drivers as well.

My aim is to avoid wasting time to create the structure of each static module each time a developer needs brand new one or a different version of it and to avoid wasting time googling for an existing solution. Usually, this activity requires to put a lot of effort in testing the static module as well. Moreover, sometimes , the solution to the same problem can be found on different sites or blogs in different flavours, which is misleading most of all for developers who have no experience in the management of static modules in wildfly.

The idea: share the descriptor of the static module in a place accessible to all the developers. The tool used to save the descriptor files must be able to version them. Each time the wildfly deployer is asked for a static module which is not bunlded in the default package or is not already available locally, the module descriptor and its resource and dependencies will be built automatically.

The solution design: wildfly is already able to download the components of a static module from an artifact repository, but this feature strictly relates to the resources.

It would be useful to improve this feature in order to create a static module locally each time the module is requested by a subsystem or an application being deployed. The deployer should first check for the local module availability. If the module is not available locally, wildfly will first search for the module descriptor into the artifact repository (maven repo implementation), then create folder tree, download resources and repeat iteratively the algorithm for each dependency found in the module descriptor.

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Andrea Battaglia
EMEA Middleware Architect

Red Hat
Via Generale Gustavo Fara, 26
20124 MILANO
www.redhat.com
mobile: +39 328 1093652
fax: +39 02 6693111
email: andrea.battaglia@redhat.com