How to override a build time property from extension A in an extension B build step?

[HerrDerb]

I have an extension B that requires extension A.
Extension A provides some build time config mappings.
I would like to override certain build time properties from extension A in extension B.

The only way which did work out for me was to define the property in a application.properties in extension b.
This is very static. Is it somehow possible to override a "foreign" build propertie inside of a build step? I could not find anything in the extension guide.

[mkouba]

I'm afraid that no such build item exists. And I have to admit that I needed it once too.

CC @radcortez

[HerrDerb]

I have a "base" extension which, next to other things, sets a few company wide properties (e.g. special db dialect). My intention was to only set those, if a certain capability (hibernate) is around.
Otherwise, I might get warnings that a unused/unmapped property exists.

[radcortez]

One possibility is to look for configuration names that you know that are only available (usually defaults) if the extension is present. You can check for those names and add your own keys in a ConfigSourceFactory.

Another possibility is to just query the Classloader for specific classes from those extensions and add your own keys. We follow that approach in the OpenTelemetry Extension.

[HerrDerb]

I guess that only works for adding, but not for overriding?

[radcortez]

You can override the config if you use the factory.

[HerrDerb]

Seems to work, when I use the extension in a project. Altought I wasn't able to write a working deployment test in my extension

[radcortez]

Seems to work, when I use the extension in a project. Altought I wasn't able to write a working deployment test in my extension

Can you please provide more information? What is the issue?

[HerrDerb]

I`ll try to make a reproducer in time