Make encoder class configurable

[parkito]

Hi,

I want to integrate LogstashEncoder with Spring-boot 3. By default SB has 2 appenders: FILE and CONSOLE. I like how they can be with SB properties. However, its not possible to override encoder class of default FILE appender, so the new appender is needed. I would like to be able override encoder class as I can do with pattern or charset.

Like

<encoder class>
            <pattern>${FILE_LOG_PATTERN}</pattern>
            <charset>${FILE_LOG_CHARSET}</charset>
           <class>{ENCODER}</>
        </encoder>

As for now, I have to define a new appender or to lose convenient SB configuration

 <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>${FILE_LOG_THRESHOLD}</level>
        </filter>
        <encoder class="net.logstash.logback.encoder.LogstashEncoder">
            <pattern>${FILE_LOG_PATTERN}</pattern>
            <charset>${FILE_LOG_CHARSET}</charset>
        </encoder>
        <file>${LOG_FILE}</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>${LOGBACK_ROLLINGPOLICY_FILE_NAME_PATTERN:-${LOG_FILE}.%d{yyyy-MM-dd}.%i.gz}
            </fileNamePattern>
            <cleanHistoryOnStart>${LOGBACK_ROLLINGPOLICY_CLEAN_HISTORY_ON_START:-false}</cleanHistoryOnStart>
            <maxFileSize>${LOGBACK_ROLLINGPOLICY_MAX_FILE_SIZE:-100MB}</maxFileSize>
            <totalSizeCap>${LOGBACK_ROLLINGPOLICY_TOTAL_SIZE_CAP:-0}</totalSizeCap>
            <maxHistory>${LOGBACK_ROLLINGPOLICY_MAX_HISTORY:-2}</maxHistory>
        </rollingPolicy>
    </appender

[philsttr]

Defining the class as an attribute of the encoder element is required by logback. Logback does not allow configuring the encoder class as a nested element.