Spring Boot - Logging

2.2.13 기준

 

Starters를 이용한다면 기본 logger는 logback이 됩니다. Java Util Logging, Commons Logging, Log4J, SLF4J 모두 동작하게 하는 dependent lib이 포함됩니다.

 

default logback 설정은 다음을 따릅니다.

github.com/spring-projects/spring-boot/blob/v2.2.13.RELEASE/spring-boot-project/spring-boot/src/main/resources/org/springframework/boot/logging/logback/base.xml

<included>
	<include resource="org/springframework/boot/logging/logback/defaults.xml" />
	<property name="LOG_FILE" value="${LOG_FILE:-${LOG_PATH:-${LOG_TEMP:-${java.io.tmpdir:-/tmp}}}/spring.log}"/>
	<include resource="org/springframework/boot/logging/logback/console-appender.xml" />
	<include resource="org/springframework/boot/logging/logback/file-appender.xml" />
	<root level="INFO">
		<appender-ref ref="CONSOLE" />
		<appender-ref ref="FILE" />
	</root>
</included>

 

4.4.6. Custom Log Configuration

Spring이 log 관련 초기화를 온전히 진행할 수 있게 하기 위해서 설정파일의 이름에 '-spring' suffix를 붙이는 것을 권장합니다. e.g. logback-spring.xml

 

spring default 설정에서 사용하는 System Property(LOG_FILE, LOG_PATH ...)는 Spring Envirenment로도 대응이 됩니다.

docs.spring.io/spring-boot/docs/2.2.13.RELEASE/reference/html/spring-boot-features.html#boot-features-custom-log-configuration

 

위의 기본 file-appender.xml 설정은 아래와 같습니다.

<appender name="FILE"
		class="ch.qos.logback.core.rolling.RollingFileAppender">
		<encoder>
			<pattern>${FILE_LOG_PATTERN}</pattern>
		</encoder>
		<file>${LOG_FILE}</file>
		<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
			<cleanHistoryOnStart>${LOG_FILE_CLEAN_HISTORY_ON_START:-false}</cleanHistoryOnStart>
			<fileNamePattern>${ROLLING_FILE_NAME_PATTERN:-${LOG_FILE}.%d{yyyy-MM-dd}.%i.gz}</fileNamePattern>
			<maxFileSize>${LOG_FILE_MAX_SIZE:-10MB}</maxFileSize>
			<maxHistory>${LOG_FILE_MAX_HISTORY:-7}</maxHistory>
			<totalSizeCap>${LOG_FILE_TOTAL_SIZE_CAP:-0}</totalSizeCap>
		</rollingPolicy>
	</appender>

 

SizeAndTimeBasedRollingPolicy를 사용하는데, size 제한이 필요 없다면 아래와 같이 TimeBasedRollingPolicy만 사용하도록 설정해주면 됩니다.

<configuration>
	<!-- use Spring default values -->
	<include resource="org/springframework/boot/logging/logback/defaults.xml" />
	<property name="LOG_FILE" value="${LOG_FILE:-${LOG_PATH:-${LOG_TEMP:-${java.io.tmpdir:-/tmp}}}/spring.log}"/>
	<include resource="org/springframework/boot/logging/logback/console-appender.xml" />

	<!-- SizeAndTimeBasedRollingPolicy 사용하지 않고 TimeBasedRollingPolicy 사용하기 위해 별도로 설정 -->
	<appender name="FILE"
			  class="ch.qos.logback.core.rolling.RollingFileAppender">
		<encoder>
			<pattern>${FILE_LOG_PATTERN}</pattern>
		</encoder>
		<file>${LOG_FILE}</file>
		<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
			<cleanHistoryOnStart>${LOG_FILE_CLEAN_HISTORY_ON_START:-false}</cleanHistoryOnStart>
			<fileNamePattern>${ROLLING_FILE_NAME_PATTERN:-${LOG_FILE}.%d{yyyy-MM-dd}.gz}</fileNamePattern>
			<maxHistory>${LOG_FILE_MAX_HISTORY:-7}</maxHistory>
			<totalSizeCap>${LOG_FILE_TOTAL_SIZE_CAP:-0}</totalSizeCap>
		</rollingPolicy>
	</appender>
</configuration>