Allow specifying a different management access log prefix

[frzme]

Currently access logs created by the management server (when the management server is run on a different port) automatically get the prefix "management_" prepended (implemented in org.springframework.boot.actuate.autoconfigure.web.servlet.ServletManagementChildContextConfiguration ).
For configurations of access logs which write to stdout (see Scout24/tomcat-stdout-accesslog#2 for an example on how to configure that in tomcat) it would be useful to be able to drop this prefix.
There might also be people interested in configuring this static prefix.

Please expose the prefix as a property and thus make it configurable by end users.

[frzme]

Note:
as a workaround I tried deactivating the customizer by overriding the Bean like this:

@ManagementContextConfiguration(ManagementContextType.CHILD)
class ServletManagementChildContextConfiguration {
	@Bean
	@Primary
	@ConditionalOnClass(name = "org.apache.catalina.valves.AccessLogValve")
    public WebServerFactoryCustomizer<TomcatServletWebServerFactory> tomcatAccessLogCustomizer() {
        return server -> {

        };
	}
}

This however turned out to not work, any hints on a possible workaround?
I then tried to run the same functionality as implemented in ServletManagementChildContextConfiguration but that ended up changing the valve in my main context. Any hints for me to understand this behaviour?

[philwebb]

For a workaround you could your write your own WebServerFactoryCustomizer ordered above ours that removes the default AccessLogValve from getEngineValves and replaces it with subclass that overrides setPrefix but doesn't call super.

[skarzhevskyy]

workaround code that works for us

/**
 * Add this class to /META-INF/spring.factories under the {@code org.springframework.boot.actuate.autoconfigure.web.ManagementContextConfiguration}
 */
@ManagementContextConfiguration(value = ManagementContextType.CHILD)
public class MyAppManagementConfig {

    @Bean
    public WebServerFactoryCustomizer<TomcatServletWebServerFactory> managementServerustomizer() {
        return factory -> {
            AccessLogValve accessLogValve = findAccessLogValve(factory);
            if ((accessLogValve != null) && "management_stdout".equals(accessLogValve.getPrefix())) {
                accessLogValve.setPrefix("stdout");
            }
        };
    }

    private static AccessLogValve findAccessLogValve(TomcatServletWebServerFactory factory) {
        return (AccessLogValve) factory.getEngineValves().stream()
                .filter(AccessLogValve.class::isInstance)
                .findFirst().orElse(null);
    }
}