Get rid off Janino condition tags for the pattern and simplify it with variable reference The <if> tag requires the Janino library with full java compiler while we just need a simple pattern matching by env var. The solution is to declare two <property> constants with the pattern and then chose one of the constants as a pattern. If SINGLE_LINE_P…

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <include resource="org/springframework/boot/logging/logback/defaults.xml"/>
  <property scope="context" name="pattern.singleLine.true" value="%d{yyyy-MM-dd'T'HH:mm:ss.SSS'Z', UTC} %5p %logger [%t] \(%X{trace}\) %X{loggingMessageExtender}: %replace(%m%n%ex){'\n(?=[^$])','\\n'}%nopex" />
  <property scope="context" name="pattern.singleLine.false" value="%d{yyyy-MM-dd'T'HH:mm:ss.SSS'Z', UTC} -%5p %logger [%t] \(%X{trace}\) %X{loggingMessageExtender}: %m%n" />
  <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <Pattern>${pattern.singleLine.${SINGLE_LINE_PATTERN:-false}}"</Pattern>
    </encoder>
  </appender>
  <root level="INFO">
    <appender-ref ref="CONSOLE"/>
  </root>
</configuration>