console pattern not recognized in logback-spring.xml - spring-boot

Question

I already looked up on stackoverflow but I did not find something comparable.
I use spring boot with following dependencies:
spring-boot 2.2.1 with
spring-boot-starter-logging 2.2.1
logback-core 1.2.3
logback-classic 1.2.3
I want to use a custom pattern for my log output to print my mdc.variables on console. Which works via application.properties
logging.level.com.mypackage=TRACE
logging.pattern.level=%d{yyyy-MM-dd HH:mm:ss} [%t] [myMdc:%X{myMdcVariable}] %-5level %logger{36} - %m%n
But I get double entries but I can not set the additivity property via application.properties. I have to use logback-spring.xml. Which looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<include resource="org/springframework/boot/logging/logback/defaults.xml"/>
<include resource="org/springframework/boot/logging/logback/console-appender.xml"/>
<root level="INFO">
<appender-ref ref="CONSOLE"/>
</root>
<logger name="com.mypackage" level="TRACE" additivity="false">
<appender-ref ref="CONSOLE"/>
</logger>
<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<Pattern>
%d{yyyy-MM-dd HH:mm:ss} [%t] [myMdc:%X{myMdcVariable}] %-5level %logger{36} - %m%n
</Pattern>
</encoder>
</appender>
</configuration>
This solves the double entries. But the pattern is not use for the logoutput. I can have either double entries or no pattern because it is not possible to combine configuration via application.properties and logback-spring.xml. What am I doing wrong?

Answer 1

I finally found out what is wrong. I checked the defaults.xml and the ConsoleAppender.xml on github e.g.
https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot/src/main/resources/org/springframework/boot/logging/logback/defaults.xml
https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot/src/main/resources/org/springframework/boot/logging/logback/console-appender.xml
The solution was to define the constant CONSOLE_LOG_PATTERN. And to define it before importing the defaults.xml and console-appender.xml
My working config file looks now like this:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<property name="CONSOLE_LOG_PATTERN" value="%d{yyyy-MM-dd HH:mm:ss} [%t] [myMdc:%X{myMdcVariable] %-5level %logger{36} - %m%n"/>
<include resource="org/springframework/boot/logging/logback/defaults.xml"/>
<include resource="org/springframework/boot/logging/logback/console-appender.xml"/>
<root level="INFO">
<appender-ref ref="CONSOLE"/>
</root>
<logger name="com.mypackage" level="TRACE" additivity="false">
<appender-ref ref="CONSOLE"/>
</logger>
<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<pattern>
${CONSOLE_LOG_PATTERN}
</pattern>
</encoder>
</appender>
</configuration>