I mistakenly send this to wildfly google groups some time ago, but it
should have been sent to the WildFly Dev mailing list.
---------- Forwarded message ---------
From: Yeray Borges Santana <yborgess(a)redhat.com>
Date: Fri, Dec 17, 2021 at 11:00 AM
Subject: Re: [wildfly-dev] Creating -jakarta variants of WildFly artifacts
using source transformation
To: WildFly <wildfly(a)googlegroups.com>
We have recently reorganized the different pieces that build the
wildfly-preview Galleon Pack ; the motivation of this change is to be
able to selectively pick up whatever we need to build other Galleon
Packs. We have now different modules for Jakarta artifacts and galleon
content related to Microprofile and non MicroProfile stuff, and a new
module to hold all the Jakarta EE 9 API.
This new code structure changes a bit two steps of Brian's tutorial. Please
follow up with them if you have a related PR in progress or are going to
create a new one soon, thanks.
On Wed, Oct 20, 2021 at 10:05 PM Brian Stansberry <
Last July, I started a thread here about ways to get native
namespace variants of artifacts, which we need for our move to EE 10. One
of the items discussed there was "5) New maven module, transform source
and build". I'm posting here as a kind of status update and tutorial about
At this point there are 11 maven modules in the WildFly main source
tree that are producing artifacts using the approach described there,
and there are PRs open for at least a couple more. I have filed or soon
will file JIRAs for all the remaining WF main tree's modules that
produce artifacts that WildFly Preview currently is transforming when it
provisions a server, so there will be more coming.
The high level overview of how these work is that a pom-only maven module
is created that corresponds to an existing module that produces an javax
artifact. The new module's pom uses the batavia maven plugin (and
Eclipse Transformer under the covers) to find the source code from the
existing maven module, transform it, and write the transformed output to
the target/ dir of the new module, specifically in the
'generated-test-sources' dirs. That generated source is then associated
with the overall maven execution for the module, and thereafter gets
included as part of the subsequent compile, test, package, install and
deploy goals executed for the module. So, presto we have native jakarta
source available that is then compiled and tested and used to
package/install/deploy binary, source and javadoc jars.
The generated source does not get committed into the git repository. The
git repo only has the pom.
It's a common thing for generated source to be used in an artifact build;
for example it's the technique we use to generate implementation classes
from the XXXLogger interfaces we have for each of our subsystems. What
we're doing here just takes this concept to the max by generating 100% of
the source, including test source.
I'm going to use a PR I sent up yesterday to illustrate how to create one
1) Decide whether the module you want to work on is ready. If you're not
the component lead responsible for the module, ask that lead. To see if a
module is 'ready', look at its compile time dependencies and see if it
still depends on other artifacts for which a native jakarta variant is
needed and doesn't exist yet. Ask here or in zulip if you are not sure!
Things can change quickly, and there also may be some edge cases where
you'd think you need a jakarta namespace dependency but you really don't.
If there are dependencies that are not ready yet, stop and wait until they
are available. Or be prepared for your new module to not build, at which
point you can save your work and wait.
2) Create a new dir under ee-9/source-transform for your new module. If
the module you are transforming isn't directly under the root of the WF
source, then create a matching structure under ee-9/source-transform. For
example, I created ee-9/source-transform/jpa/spi to produce a jakarta.*
variant of jpa/spi.
3) Copy the pom.xml from an *existing source-transform module* into your
new dir. Easiest is to use one that comes from a dir the same # of levels
below source-transform as your new dir, so a couple relative paths in your
new pom are correct. For my PR I copied over
Don't start with the pom from your source input module. Unless you want to
work out how to adapt it to use the source transformation. :) Granted it's
not rocket science. But it's easier for code reviewers to look at these if
they look like the other ones.
4) Change the artifactId in your new pom to *exactly* match the artifactId
of the module you're transforming, but with "-jakarta" appended:
5) Change the 'name' tag to something appropriate, like
6) Change the 'transformer-input-dir' maven property to point to the root
of the module you are transforming:
This property is used in the batavia maven plugin config in the parent
source-transform dir. Each child module sets the property to point to the
correct input source for that module.
This one small tweak is the only thing you need to deal with to get the
source transformation set up.
7) Configure dependencies.
a) Delete the existing 'dependency' entries in your new pom, as they are
for whatever random file you copied in.
b) Copy over the 'dependency' entries from the pom of the module you are
c) For any entries where your new artifact uses a dependency with a
different groupId:artifactId from the one you're transforming, change the
GA. For example:
EE 8 JTA
became EE 9.1 JTA
Or, in another example
an EE 8 based 'ee' subsystem module dep:
became instead a dep on the new '-jakarta' variant:
d) A nice to have is to separate from the others in the dependency listing
deps where WF Preview is using a different artifact from what standard WF
is using. For example see
This separation helps code reviewers.
8) Tell your new module's parent to include it in the build:
9) The ee-9/pom.xml maintains a dependencyManagement set for all artifacts
that differ in WF Preview from what is in standard WF. These can either be
artifacts whose GA is not used at all in standard WF, or ones where WF
Preview uses a different version. Add your new artifact to this
10) Allow re-use of the module.xml that incorporates this artifact between
standard WF and WF Preview. This is done by modifying the module.xml to add
an expression that the maven-resource-plugin replaces when preparing the
module.xml resource file for use in the FP build:
The added @module.jakarta.suffix@ gets replaced either with an empty
string (standard WF) or "-jakarta" (WF Preview)
11) Add your new artifact as a dependency of ee-9/feature-pack/pom.xml.
This is needed so the wildfly-preview Galleon feature pack can utilize your
We are no longer adding artifacts to ee-9/feature-pack/pom.xml. Your new
artifact should be now placed under:
11.a) ee-9/common-microprofile; if your artifact is a MicroProfile related
11.b) Otherwise, place it under ee-9/common
Notice that these artifacts, together with the ee-9 API ones, are now
pulled in into ee-9/feature-pack:.
12) Tell the wildfly-preview feature-pack build to ignore the no-longer
relevant javax artifact you're replacing. This saves build time, compute
resources and false positives in the build log that make us think your
artifact hasn't been handled yet.
(Note the precise spot to put that 'exclude' may differ, a bit. Ask if
this is unclear.)
13) Add an entry for your new artifact in the license.xml file for the
wildfly-preview feature back. Put it in the right alphabetical spot based
on its groupId and artifactId.
Similar to the artifacts change, the license file is now split in
MicroProfile and non Microprofile related:
14) Do a build and if good, commit and send up a PR! If your input module
had tests, your new module should as well and they should run. If you're
curious, have a look in the new target/generated-xxx dirs to see the
This sounds like a lot, and I suppose it is, but other than step 7) it's
all very simple stuff, mostly things you'd do any time you add a new module
to the WF source tree. Granted I'm practiced at this, but it took me about
half an hour to work up the PR I've been using as an example.
If you're interested in doing one of these, and the component lead
responsible for the input module is agreeable, please go for it and feel
free to ask for help.
 Child modules under
 High level tracker issues for this work are
. I'm filing separate issues
for individual pieces and am linking those to one or the other of these two
shows all artifacts (not just those from the WF source tree) that the
WildFly Galleon plugin was transforming in builds on Oct 14. The rows that
end with '-26.0.0.Beta1-SNAPSHOT.jar' are ones that are produced by
WildFly main itself. I add new tabs to that document weekly to track
progress on reducing the # of artifacts being transformed by the Galleon
which was produced from a maven module with nothing in it but a pom.
Project Lead, WildFly
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