Jenkins pipeline运行和停止后台脚本

拼搏现实的明天。 2022-05-25 11:38 595阅读 0赞

在Pipeline运行结束后，Jenkins缺省会kill掉该Pipeline的子进程。因此在pipeline中通过`nohup java -jar app.jar > app.log &` 的方式启动的java后台进程在Pipeline结束后会被Jenkins杀掉。

解决办法是：

stage('Deploy') {
    	steps {
    		script {
    			withEnv(['JENKINS_NODE_COOKIE=background_job']) {
    				sh """
    					nohup java -jar app.jar > app.log &
    				   """
    			}
    
    		}
    	}
    }

注意：

*  在Pipeline中是通过设置JENKINS\_NODE\_COOKIE来让Jenkins不要kill掉Pipeline后台子进程，而在Freestyle job中是通过设置BUILD\_ID。
 *  如果要在一个Pipeline中后台启动多个是script，把多个`nohup`启动命令放到一个`withEnv(['JENKINS_NODE_COOKIE=background_job']) {...}`中启动

上面的`nohup`命令也可以替换为：

nohup java -jar app.jar > app.log 2>&1 &

或不输出日志

nohup java -jar app.jar > /dev/null 2>&1 &

Kill掉一个后台进程：

sh '''
        if [ `ps -ef | grep runserver | grep venv  | grep python3 | grep -v grep | awk '{print $2}'` ];then
            . .venv/bin/activate
    		ps -ef | grep runserver | grep venv  | grep python3 | grep -v grep | awk '{print $2}' | xargs kill -9 
        fi
    '''

或

// Stop application through kill process
    PROCESS_ID = sh (script: "ps -ef | grep ${GIT_REPO_PROJECT} | grep java | grep jar | grep -v grep | grep -v pipeline | awk -F ' ' '{print \$2}'", returnStdout: true).trim()
    
    echo "PROCESS_ID=" + PROCESS_ID
    
    if (PROCESS_ID != "") {
        sh """
             echo "Kill process: ${PROCESS_ID}"
             sudo kill -9 ${PROCESS_ID}
            """
    }

参考文档：

*  [https://wiki.jenkins.io/display/JENKINS/Spawning+processes+from+build][https_wiki.jenkins.io_display_JENKINS_Spawning_processes_from_build]
 *  [https://devops.stackexchange.com/questions/1473/running-a-background-process-in-pipeline-job][https_devops.stackexchange.com_questions_1473_running-a-background-process-in-pipeline-job]
 *  [https://issues.jenkins-ci.org/browse/JENKINS-28182][https_issues.jenkins-ci.org_browse_JENKINS-28182]
 *  [http://excid3.com/blog/running-background-daemon-scripts-with-jenkins][http_excid3.com_blog_running-background-daemon-scripts-with-jenkins]

## java not found问题 ##

最近遇到一个古怪问题，运行 `nohup java -jar app.jar > /dev/null 2>&1 &` 命令后，进程没有启动。一开始怀疑是Jenkins在流水线结束后把后台进程杀掉了，搞了半天没有搞定。后面直接运行`java -jar app.jar`才发现是`java not found`。

原来这台机器上的jdk不是标准安装，导致`/bin/java`不存在，而Jenkins运行时是到`/bin`目下查找命令的。

解决方法：

# 检查java安装位置
    which java
    # 创建/bin/java的soft link，比如：
    ln -s /home/bin/jdk-13/bin/java /bin/java
    # 检查/bin/java文件类型
    file /bin/java

[https_wiki.jenkins.io_display_JENKINS_Spawning_processes_from_build]: https://wiki.jenkins.io/display/JENKINS/Spawning+processes+from+build
[https_devops.stackexchange.com_questions_1473_running-a-background-process-in-pipeline-job]: https://devops.stackexchange.com/questions/1473/running-a-background-process-in-pipeline-job
[https_issues.jenkins-ci.org_browse_JENKINS-28182]: https://issues.jenkins-ci.org/browse/JENKINS-28182
[http_excid3.com_blog_running-background-daemon-scripts-with-jenkins]: http://excid3.com/blog/running-background-daemon-scripts-with-jenkins