How to use Log4J2 composite configuration with Spring Boot

Question

I am using Spring Boot 2.0.1 starter with log4j2 using following POM. WAR file is hosted in Tomcat 8 (instead of using embedded tomcat). Application logs are written to console instead of writing to log file. Apparently Spring Boot's XML configuration is overwrites the one configured in application.

POM:

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-web</artifactId>
    </dependency>

Log4j2 uses composite configuration where configuration is split in 2 xml files: log4j2-base.xml and log4j2-env.xml

Resources directory contains log4j2.component.properties with following content:

log4j.configurationFile=log4j2-base.xml,log4j2-env.xml

Resources directory also contains log4j2-base.xml. File log4j2-env.xml is part of environment specific JAR file that is already placed into class path.

Log:

DEBUG StatusLogger Configuration XmlConfiguration[location=jar:file:/usr/mware/jwsAppDetails/app1/webapps/myProject/WEB-INF/lib/spring-boot-2.0.1.RELEASE.jar!/org/springframework/boot/logging/log4j2/log4j2.xml] initialized
DEBUG StatusLogger Starting configuration XmlConfiguration[location=jar:file:/usr/mware/jwsAppDetails/app1/webapps/myProject/WEB-INF/lib/spring-boot-2.0.1.RELEASE.jar!/org/springframework/boot/logging/log4j2/log4j2.xml]
DEBUG StatusLogger Started configuration XmlConfiguration[location=jar:file:/usr/mware/jwsAppDetails/app1/webapps/myProject/WEB-INF/lib/spring-boot-2.0.1.RELEASE.jar!/org/springframework/boot/logging/log4j2/log4j2.xml] OK.
TRACE StatusLogger Stopping org.apache.logging.log4j.core.config.composite.CompositeConfiguration@40575bb9 [configurations=[XmlConfiguration[location=/usr/mware/jwsAppDetails/app1/webapps/myProject/WEB-INF/classes/log4j2-base.xml], XmlConfiguration[location=jar:file:/usr/mware/jwsAppDetails/app1/lib/myProject.jar!/log4j2-env.xml]], mergeStrategy=org.apache.logging.log4j.core.config.composite.DefaultMergeStrategy@583fc0cb, rootNode=null, listeners=[], pluginPackages=[], pluginManager=org.apache.logging.log4j.core.config.plugins.util.PluginManager@278307b, isShutdownHookEnabled=true, shutdownTimeoutMillis=0, scriptManager=org.apache.logging.log4j.core.script.ScriptManager@185463aa]...
TRACE StatusLogger CompositeConfiguration notified 8 ReliabilityStrategies that config will be stopped.
TRACE StatusLogger CompositeConfiguration stopping 7 LoggerConfigs.
TRACE StatusLogger CompositeConfiguration stopping root LoggerConfig.
TRACE StatusLogger CompositeConfiguration notifying ReliabilityStrategies that appenders will be stopped.
TRACE StatusLogger CompositeConfiguration stopping remaining Appenders.
DEBUG StatusLogger Shutting down RollingFileManager null
DEBUG StatusLogger Shutting down RollingFileManager {}null
DEBUG StatusLogger All asynchronous threads have terminated
DEBUG StatusLogger RollingFileManager shutdown completed with status true
DEBUG StatusLogger Shut down RollingFileManager null, all resources released: true
DEBUG StatusLogger Appender RollingFile stopped with status true
TRACE StatusLogger CompositeConfiguration stopped 1 remaining Appenders.
TRACE StatusLogger CompositeConfiguration cleaning Appenders from 8 LoggerConfigs.
DEBUG StatusLogger Stopped org.apache.logging.log4j.core.config.composite.CompositeConfiguration@40575bb9 [configurations=[XmlConfiguration[location=/usr/mware/jwsAppDetails/app1/webapps/myProject/WEB-INF/classes/log4j2-base.xml], XmlConfiguration[location=jar:file:/usr/mware/jwsAppDetails/app1/lib/myProject.jar!/log4j2-env.xml]], mergeStrategy=org.apache.logging.log4j.core.config.composite.DefaultMergeStrategy@583fc0cb, rootNode=null, listeners=[], pluginPackages=[], pluginManager=org.apache.logging.log4j.core.config.plugins.util.PluginManager@278307b, isShutdownHookEnabled=true, shutdownTimeoutMillis=0, scriptManager=org.apache.logging.log4j.core.script.ScriptManager@185463aa] OK
TRACE StatusLogger Reregistering MBeans after reconfigure. Selector=org.apache.logging.log4j.core.selector.ClassLoaderContextSelector@77aa3299
TRACE StatusLogger Reregistering context (1/1): '2190fd23' org.apache.logging.log4j.core.LoggerContext@64150381

Answer 1

We tried the following and it worked:

1. Rename the file log4j-base.xml to log4j2.xml

2. In log4j2.component.properties, rename log4j-base.xml to log4j2.xml like below:

   log4j.configurationFile=log4j2.xml,log4j2-env.xml