How can I programmatically set a Spring property during AOT processing?

I'm building a library module as an helper for building native images for Spring apps, for example adding AOT bean processor and filters. I also need to set some Spring properties during AOT that would then activate some bean definitions to be found and registered during AOT.

Being this a library, I don't have control on the app that is being built so I can't use properties files or environment variables to set properties. I have tried to use EnvironmentPostProcessor but it looks like it's not evaluated during AOT processing:

class EnableKubernetesEnvironemntPostProcessor implements EnvironmentPostProcessor {

    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        environment.getPropertySources().addFirst(new MapPropertySource("enableKubernetes", Map.of(
                "spring.main.cloud.platform", "kubernetes",
                "spring.profiles.active", "kubernetes",
                "management.server.port", "9000"
        )));
    }
}

How can I programmatically set a Spring property during AOT processing? Is it possible to trigger EnvironmentPostProcessor during AOT?

In particular, I need to set spring.main.cloud.platform=kubernetes and spring.profiles.active=kubernetes so AOT picks up beans conditional to those properties, and management.server.port so AOT is aware to use a different container for the Actuator.

Solution

This sample project should hopefully provide what you need.

The cloud platform property was wrong. It should have been spring.main.cloud-platform. For cases like this, it's always better to give that a try manually in an app and then move to an EnvironmentPostProcessor.

Then you probably don't want that stuff to apply when you run any app that has the library. To mitigate with that, you can check if you're running AOT processing and only enable that behavior there.

Here's the code

class TestEnvironmentPostProcessor implements EnvironmentPostProcessor {

    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        if (Boolean.getBoolean(AbstractAotProcessor.AOT_PROCESSING)) {
            environment.addActiveProfile("kubernetes");
            environment.getPropertySources().addFirst(new MapPropertySource("aot", Map.of(
                    "spring.main.cloud-platform", "kubernetes")));
        }
    }

}

I am not 100% sure why setting the profile property doesn't enable it but manipulating the Environment directly is better anyways.