[wildfly-dev] EE level java:comp/DefaultDataSource for WildFly 8...

[David M. Lloyd]

On 09/24/2013 05:14 AM, Eduardo Martins wrote:
> Maybe we should create a doc with a reference design, since there are several default EE resources among our subsystems...
>
> IMHO default EE resources should be defined in the related subsystem configuration, otherwise the EE subsystem config will always be changing. In this case there should a configuration in the Datasources subsystem such as:
>
> <subsystem xmlns="urn:jboss:domain:datasources:2.0">
>         <datasources>
>         		<default-datasource jndi-name="java:jboss/datasources/ExampleDS" />
> 		<datasource jndi-name="java:jboss/datasources/ExampleDS" pool-name="ExampleDS" enabled="true" use-java-context="true">
> 			...
> 	        </datasource>
>          	...
>         </datasources>
> </subsystem>
>
> For an easier/faster logic to find the default resource, and since we don't officially support linkref on jndi, the subsystem management op that adds the default resource (in this case default-datasource) should create a binder service pointing to a *fixed* jndi name (let's says java:jboss/ee/default/datasource) and inject it with the target resource (in this case the jndi name java:jboss/datasources/ExampleDS).
>
> Then the subsystem should provide a DUP that for EE modules do the required default bindings, in this case java:comp/DefaultDataSource and/or java:module/DefaultDataSource
>
> The subsystem then also needs to take care of the default mapping to the *fixed* jndi name from @Resource injection, this can be accomplished by adding a EEResourceReferenceProcessor to the EEResourceReferenceProcessorRegistry present in DU attachment with key org.jboss.as.ee.component.Attachments.RESOURCE_REFERENCE_PROCESSOR_REGISTRY

I don't know, I guess I'm running out of opinion on this.

Here's a list of options:

1) Enhance naming subsystem to be able to bind java:comp, java:module, 
java:app names, and put config in that subsystem (modify JMS and other 
subsystems with implicit bindings to do the same)
2) Enhance datasources subsystem to include a default datasource 
attribute (== XML element) which, when present, will set up implicit 
bindings for java:comp (and make sure that the config looks/acts 
similarly between JMS, DS, and any other subsystem with implicit bindings)
3) Decide it's all the EE subsystem and put implicit bindings in there

Decision time: GO!
-- 
- DML