Hi Gianny,
First, I'd like to make sure I understand the philosophy behind your
proposals. IIUC they both involve the idea of making it easy to
modify an existing plugin rather than making it easy to replace an
existing plugin with a similar one.
Why is this a good idea? My idea has been that we should make it
easier to replace a plugin with a similar one than modify an existing
one, and then we will have the best of all worlds.
All this being said, I think your ideas are both quite interesting.
I'm especially interested in the groovy builder approach.
I'll be fairly unavailable until next week but might keep thinking
about this anyway.
thanks!
david jencks
On Oct 15, 2008, at 3:46 AM, Gianny Damour wrote:
On 15/10/2008, at 4:16 AM, David Jencks wrote:
That's one of the main missing bits of functionality. Right now
the only way to get the g-p.xml is to use c-m-p or to export the
plugin from a server it's been deployed into, or to do something by
hand with jar packing and unpacking.
The biggest problem here, in my mind, is that jsr88 only wants you
to have one "plan": to deploy something you get to specify the
artifact and one "plan". Our deployment system is built around
jsr88 so we either have to condense the g-p.xml and plan into one
"plan" or abandon jsr88.
At the moment I'm thinking that one satisfactory solution might be
to more or less embed the plan into g-p.xml. Perhaps we could
avoid duplicating most of the dependency info by adding the
<import> element to the dependencies in g-p.xml. I guess we'd
expect a more or less empty <environment> element in the plan and
fill in the dependencies from the g-p.xml when deploying.
I guess another possibility might be to include the info from g-
p.xml in the environment element of the plan.
I've been thinking about this on and off for a long time and don't
have any solution I'm entirely happy with so discussion and more
ideas are more than welcome :-)
Hi,
Another possible solution would be to allow the extension of a given
configuration by other configurations. This could work like the
web.xml fragment mechanism of the upcoming servlet specs which
allows framework libraries to transparently install Web components
to the baseline components defined by the web.xml DD.
When a configuration starts it looks for complementing
configurations whose responsibility is to alter the baseline
configuration. The identification of complementing configurations
could be based on a simple naming convention scheme, e.g. if the
base configuration is org/tomcat6//car then all the configurations
matching the pattern org/tomcat6-transform-DiscriminatorName//car
are identified as complementing configurations.
If there are complementing configurations, then the baseline
ConfigurationData could be passed to them for arbitrary
transformation, e.g. add, update or remove dependencies. An updated
ConfigurationData is passed back and actually loaded by the kernel.
The main drawback of this approach is the added configuration
complexity. The main benefits is that it provides application server
configuration traceability and a mean to perform very simple changes
to a baseline configuration w/o having to redefine in its entirety
the configuration to be slightly changed.
In another thread about scripting language integration, I suggested
an even simpler approach whereby a script is executed to perform
ConfigurationData transformations.
If any of these two options are plausible solutions, then I am happy
to move forward with an implementation.
Thanks,
Gianny
thanks
david jencks