Logback I want File do not create when the appender is never used. [RollingFileAppender]

I'm creating a logback-common config file for my applis. I'm defining a RollingFileAppender in it, that for all my applis generates the same log format in a file (if we need it). Sometimes I want to use this appender, and sometimes not (when we test for example).

So we configure our specific logback-{profile}.xml depending what we want. But when we do not use the FILE appender, the file gets created and I would like not.

I have:

• logback-common.xml >> with all appenders definition (FILE and COMMON) appli_one
• resources/logback.xml >> call logback-common and config/logback-{profile}.xml
• resources/config/logback-{profile}.xml >> specific appli/profile logback configuration.

To configure we can do in logback-{profile}.xml

    <root level="WARN">
    <appender-ref ref="FILE"/> <!-- For File Log when we need it -->
    <appender-ref ref="CONSOLE"/>
    </root>


    <root level="WARN">
    <!-- <appender-ref ref="FILE"/> --> <!-- in comment when we do not need if > BUT create a empty file -->
    <appender-ref ref="CONSOLE"/>
    </root>

logback-common.xml

    <included>
    <!-- The FILE and ASYNC appenders are here as examples for a production
        configuration -->
    <appender name="FILE"
              class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>log/${spring.application.name}.log</file>
        <rollingPolicy
                class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>
                log/${spring.application.name}.%d{yyyy-MM-dd}.%i.log.zip
            </fileNamePattern>
            <maxHistory>90</maxHistory>
            <maxFileSize>10MB</maxFileSize>
        </rollingPolicy>
        <encoder>
            <charset>utf-8</charset>
            <Pattern>%d %-5level [%thread] %logger{0}: %msg%n</Pattern>
        </encoder>
    </appender>


    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>"%d{yyyy-MM-dd} [%thread] %-5level %45logger{45} - %msg%n"</pattern>
        </encoder>
    </appender>

    </included>

logback.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <configuration scan="true" packagingData="true">

        <property name="spring_profiles_active" value="${spring.profiles.active}" />

        <property resource="application.properties"/>

        <include resource="config/log/logback-common.xml"/>
        <include resource="config/log/logback-${spring_profiles_active}.xml"/>
    </configuration>

Not a core feature of logback but there are workarounds to achieve lazy file initialization.

See more here Logback - do not create empty log files at startup