Following version 2.5 update (specifically, modification of Environment in https://github.com/spring-projects/spring-boot/issues/24892), we cannot add propertySource files correctly with an EnvironmentPostProcessor.

Here is what we did previously: in a common library for several applications (mainly of webApplicationType = REACTIVE), an EnvironmentPostProcessor was used to:

  • Add a yaml files with multiple profiles to define some common properties. These common properties sometimes refer to environment variables defined in real environments (eg. api.port in the example). This file also defines some profiles groups. Here is a shortened example:
server:
  port: ${api.port:80}
  max-http-header-size: ${project.max-http-header-size:16KB}
  shutdown: ${project.shutdown:graceful}
spring:
  profiles:
    group:
      full_debug:
      - http_trace
      - messaging_trace
---
spring:
  config:
    activate:
      on-profile: http_trace
okhttp:
  log:
    enabled: true
    content: BODY
    level: debug
  • To enable easier work locally, whenever some profile is active, another file is added with some default values for the properties matching environment variables. Here is another shortened example file for this case.
api:
  port: ${env.api.port:8080}

The class adding this behaviour looks something like this:

class DxpPropertiesEnvironmentPostProcessor : EnvironmentPostProcessor, Ordered {

    companion object {
        private const val CORE_FILE = "core.yml"
        private const val ENV_DEV_PROPERTY_FILE = "env-dev.yml"
        private const val DEV_PROFILE = "dev"
        private val propertySourceLoader = YamlPropertySourceLoader()
    }

    override fun postProcessEnvironment(
            environment: ConfigurableEnvironment,
            application: SpringApplication,
        environment.addPropertiesFileToResourceResolvers(CORE_FILE)
    }

    private fun ConfigurableEnvironment.addPropertiesFileToResourceResolvers(filename: String) {
        load(filename)
        if (isDev()) {
            load(ENV_DEV_PROPERTY_FILE)
        }
    }

    private fun ConfigurableEnvironment.load(filename: String) {
        propertySourceLoader.load(filename, ClassPathResource(filename)).filterProfiles(activeProfiles)
                .forEach {
                    propertySources.addBefore(RANDOM_PROPERTY_SOURCE_NAME, it)
                }
    }

    private fun ConfigurableEnvironment.isDev(): Boolean {
        return acceptsProfiles { it.test(DEV_PROFILE) }
    }

    override fun getOrder() = Ordered.HIGHEST_PRECEDENCE + 1
}

We now have several issues with the new Environment implementation used (ApplicationReactiveWebEnvironment), as profiles are not resolved before ConfigDataEnvironmentPostProcessor anymore: * The if(isDev()) clause cannot resolve correctly as profiles are defined after our class * The filtering of profiles in the "core" yaml file cannot work correctly, only the "default" part being added

If we move the post processor after ConfigDataEnvironmentPostProcessor, properties group defined via spring.profiles.group in the file were not present yet, and the associated profiles aren't added by ConfigDataEnvironmentPostProcessor.

Comment From: nycza

Note: we're not using Spring Cloud Config

Note 2: Creating multiple EnvironmentPostProcessors, splitting the files (one with only spring.profiles.include/spring.profiles.group properties, another with the rest of the content), and applying EnvironmentPostProcessors for profiles only files before ConfigDataEnvironmentPostProcessor / the other EnvironmentPostProcessors after ConfigDataEnvironmentPostProcessor seems to work, but I'm not sure that's the cleanest way to go about it.

Comment From: philwebb

I think splitting your EnvironmentPostProcessor is probably the quickest way to get your application working again. I can't think of how we could change things on our end to make things work as they did before without re-introducing a lot of the complications that we were trying to remove.

We need the profile groups to be setup before profiles are activated, and you can only check the dev profile after they have been activated.

The only other suggestion I have is to look at the new ConfigDataLocationResolver and ConfigDataLoader classes. They might allow you to contribute your own properties in a more natural way. The only downside is that users of your library would need to remember to add a spring.config.import entry to their application.yaml files:

application.yaml

spring:
  config:
    import: dxp:common

You might also want to track issue #24688 where we're trying to find a better general solution to this problem.

Comment From: nycza

Thanks for your quick answer, I'll keep #24688 in mind when upgrading in the future it indeed looks like it fits our usecase.