springframework中使用logback 配置日志的相对目录

缘起

前几日开发同事请求在jenkins服务器创建几个日志目录，解释说因为没有相关日志目录导致构建失败，检查构建日志发现如下错误：

Logging system failed to initialize using configuration from 'classpath:logback.xml'
java.lang.IllegalStateException: Logback configuration error detected: 
ERROR in ch.qos.logback.core.rolling.RollingFileAppender[FILE] - Failed to create parent directories for [/logs/a6/a6-ss-discovery/spring.log]
ERROR in ch.qos.logback.core.rolling.RollingFileAppender[FILE] - openFile(/logs/a6/a6-ss-discovery/spring.log,true) call failed. java.io.FileNotFoundException: /logs/a6/a6-ss-discovery/spring.log (No such file or directory)

从运维角度出发，把日志放到/目录是个稳定性的隐患，所以必须解决，反馈开发同事修改，开发同事是在太忙了，答应以后修改。于是有了本文。

设定目标

• app目录下有bin、logs目录，要求日志集中存放在logs目录下面

• 如果bin下有多个可运行app，那么logs下面创建appname的二级目录

  示例

  logs
  └── a6-ss-discovery
  ├── error.log
  ├── spring.log
  └── system.log 

修改两个文件

• src/main/resources/application.yml修改以下两处：

name字段值修改实际名称

spring:
  application:
    name: a6-ss-discovery 

path字段值修改为相对路径logs

# Logging
logging:
  config: classpath:logback.xml
  path: ../logs/${spring.application.name}

• src/main/resources/logback.xml 修改LOG_PATH的value为logs

验证

• 运行mvn构建和测试

......
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 20.344s
[INFO] Finished at: Mon Apr 10 18:51:36 CST 2017
[INFO] Final Memory: 35M/428M
[INFO] ------------------------------------------------------------------------

• 运行ls命令检查logs目录（略）