Grails 5.0.0.M2: property inside plugin has no effect on environment configuration (extension to #11519)

[davidkron]

This is an extension to the already closed issue #11519

The example which I described in my initial issue where a call to environment.getProperty('grails.databinding.dateFormats') inside BootStrap doesn't return the values from plugin.yml does work now.

But I discovered another use-case where it still doesn't work:
My example of configuring some default framework parameters like grails.databinding.dateFormats inside a "core"-plugin still doesn't work. The concrete problem in the databinding case seems to be, that the configuration is now implemented as a Micronaut @ConfigurationProperties bean:

@ConfigurationProperties("grails.databinding")
public class DataBindingConfigurationProperties {

And to me it seems that the configuration from the plugins gets added to the Micronaut context very late:

grails-core/grails-core/src/main/groovy/grails/boot/GrailsApp.groovy

Lines 99 to 107 in 77843bd

	ConfigurableApplicationContext applicationContext = super.run(args)
	Environment environment = Environment.getCurrent()
	log.info("Application starting in environment: {}", environment.getName())
	log.debug("Application directory discovered as: {}", IOUtils.findApplicationDirectory())
	log.debug("Current base directory is [{}]. Reloading base directory is [{}]", new File("."), BuildSettings.BASE_DIR)
	loadPluginConfigurationsToMicronautContext(applicationContext)

At this point the application context is already created.

Edit:
What also doesn't seem to work: when I add a custom Micronaut PropertySourceLoader the properties loaded with it are not available in the Grails application by grailsApplication.config.

Task List

• Steps to reproduce provided
• Stacktrace (if present) provided
• Example that reproduces the problem uploaded to Github
• Full description of the issue provided (see below)

Steps to Reproduce

1. create a grails plugin
2. override a default grails property (e.g. grails.databinding.dateFormats) inside the plugin's grails-app/config/plugin.yml file with a non-default value of something like "dd.MM.yyyy"
3. create a grails application
4. add plugin dependency to app
5. try databinding of a "LocalDate" property with a value of "19.03.2021"

Expected Behaviour

Configuration properties from plugins should be loaded already in the Micronaut context.

Actual Behaviour

Configuration is loaded when Micronaut context is already setup.

Environment Information

• Operating System: Windows 10
• Grails Version: 4.0.9
• JDK Version: 11

[davidkron]

So as I am currently trying to implement a workaround to make our app work, I experimented with the following extension to MicronautEnvironment, so the Spring context also receives the property sources from Micronaut:

@Replaces(MicronautEnvironment.class)
@Singleton
@Primary
@CompileStatic
class ExtendedMicronautEnvironment extends MicronautEnvironment {

    private static final Set<String> EXCLUDED_SOURCES_NAMES = Set.of(
        SystemPropertiesPropertySource.NAME,
        EnvironmentPropertySource.NAME,
        'grails-config'
    )

    ExtendedMicronautEnvironment(Environment environment) {
        super(environment)
    }

    @Override
    MutablePropertySources getPropertySources() {
        MutablePropertySources propertySources = super.getPropertySources()
        environment.propertySources
            .findAll { !EXCLUDED_SOURCES_NAMES.contains(it.name) }
            .each {
                propertySources.addLast(new MicronautPropertySource(it.name, it))
            }
        return propertySources
    }
}

During this I had to debug a lot through Spring and Micronaut and I discovered the following, which I found kinda odd and also prevents my workaround above from working:

I placed a breakpoint inside the constructor of the class org.springframework.core.env.AbstractEnvironment and found out that the Spring environment is actually created 2 times.

The first time on the line:
https://github.com/spring-projects/spring-boot/blob/fdf3b18697b171f4e184dbd8ced4461d0114cf22/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplication.java#L339
The second time on this line:
https://github.com/spring-projects/spring-framework/blob/965eee7bbfc454a6e5b304de254822743248c47c/spring-context/src/main/java/org/springframework/context/annotation/AnnotatedBeanDefinitionReader.java#L71

So the merge of the micronaut property sources (from my workaround) with the Spring context should happen at this line:

grails-core/grails-core/src/main/groovy/grails/boot/GrailsApp.groovy

Lines 186 to 188 in e8a6adb

	applicationContext.setParent(
	parentContext
	)

But at the time of execution, the active environment is actually the second instance that was created. Then after the parent context is set, the following is executed:
https://github.com/spring-projects/spring-boot/blob/fdf3b18697b171f4e184dbd8ced4461d0114cf22/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplication.java#L363-L365

These lines finally set the environment to the first instance that was created in SpringApplication.

From a theoretical standpoint I would expect there would be created exactly one Spring environment and one Micronaut environment, so this behavior seems rather strange to me.

Is this expected to work like that?