问题：

jenkins的shell中执行nohup java -jar xxx.jar &，构建成功后在服务器上通过jps、netstat、ps等命令发现均无法查到进程

原因：

1. 没有合理设置环境变量BUILD_ID、JENKINS_NODE_COOKIE
2. 执行nohup java -jar xxx.jar &命令时已经离开了该 job 的WORKSPACE
3. ssh管道到其他node执行nohup java -jar xxx.jar &时环境变量缺失

方案：

#!/bin/bash

export MAVEN_HOME=/home/maven/apache-maven-3.8.3
export PATH=${MAVEN_HOME}/bin:${PATH}
export JAVA_HOME=/home/java/jdk1.8.0_202
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib:$CLASSPATH
export JAVA_PATH=${JAVA_HOME}/bin:${JRE_HOME}/bin
export PATH=${JAVA_PATH}:${PATH}
export BUILD_ID=dontKillMe

pkg_name="com-0.0.1-SNAPSHOT.jar"
share_dir="${WORKSPACE}/target/"
port="8084"
log_file="nohup.out"
log_file_archived="nohup_archived.out"


function _get_pid(){
    app_pid="`netstat -anpt | grep "0.0.0.0:${port}" | awk '{print $7}' | awk -F'/' '{print $1}'`"
    echo $app_pid
}


function _logs_status(){
    for((i=1;i<=30;i++));  
        do  
            sleep ${i}s
            run_status="`egrep 'Started ComApplication in' ${share_dir}${log_file} | wc -l`"
            if [ ${run_status} == 1 ];then
                tail -50 ${share_dir}${log_file}
                app_pid="`_get_pid`"
                echo "====== server start success ======"
                echo "app_pid: ${app_pid}"
                break
            fi
        done
    if [ ${run_status} == 0 ];then
        echo "====== server start failed ======"
        exit 128
    fi
}


function _stop(){
    app_pid="`_get_pid`"
    echo "app_pid: ${app_pid}"
    
    if [ -z "${app_pid}" ];then
        echo "====== server is stoped ======"
    else
        kill -9 ${app_pid}
        sleep 10s
        app_pid="`_get_pid`"
        if [[ -z "${app_pid}" ]];then
            echo "====== server stoped success ======"
        else
            echo "====== server stoped failed ======"
            exit 127
        fi
    fi
}


function _start(){
    # cp -rf ${WORKSPACE}/target/${pkg_name} ${share_dir}
    cd ${share_dir} && \
    chmod 777 ${pkg_name} && \
    tail -200 ${share_dir}${log_file} >> ${share_dir}${log_file_archived} && \
    rm -rf ${share_dir}${log_file}
    export JENKINS_NODE_COOKIE=dontKillMe 
    export BUILD_ID=dontKillMe 
    nohup java -jar ${share_dir}/${pkg_name} &>${share_dir}${log_file} &
    sleep 5s
    _logs_status
}


function _restart(){
    _stop
    _start
}


function _main(){
    _restart
}


_main