Linux 配置tomcat应用开机启动

服务主要以service为扩展名，文件路径为/usr/lib/systemd/system/。需要用root用户操作

1、创建服务文件

以tomcat服务为例，使用命令创建服务文件：

touch /usr/lib/systemd/system/tomcat.service

2、编写服务内容

vim /usr/lib/systemd/system/tomcat.service

[Unit]
Description=Apache Tomcat
After=network-online.target
Wants=network-online.target

[Service]
Type=forking
ExecStart=/www/tomcat/bin/deploy.sh start
ExecReload=/www/tomcat/bin/deploy.sh restart
ExecStop=/www/tomcat/bin/deploy.sh stop
User=wangjs
Group=wangjs

[Install]
WantedBy=multi-user.target

其中[Service]模块下的Type分为forking与simple两种:
区别在于执行脚本时会不会独占shell，如果可以后台运行，则使用forking，否则使用simple。
比如tomcat/nginx应用启动后会自动后台运行，则使用forking，而java -jar *.jar命令运行后会独占shell，则使用simple。
注意User/Group如果不写则默认以root用户运行，如果指定需要手动添加。

3、加载服务

服务内容编写或修改之后需要对systemd重新加载服务才能生效：

systemctl daemon-reload

4、配置服务开机启动

systemctl enable tomcat   配置开机启动
systemctl cat tomcat  查看服务内容
systemctl start tomcat  启动服务
systemctl stop tomcat  停止服务
systemctl status tomcat  查看服务状态

5、脚本中 deploy.sh 分享

#!/bin/bash

PROG_NAME=$0
ACTION=$1
APP_START_TIMEOUT=120
APP_PORT=2021
HEALTH_CHECK_URL=http://127.0.0.1:${APP_PORT}
APP_NAME=tomcat

usage() {
    echo "Usage: $PROG_NAME {start|stop|restart}"
    exit 2
}

health_check() {
    exptime=0
    echo "checking ${HEALTH_CHECK_URL}"
    while true
        do
            status_code=`/usr/bin/curl -L -o /dev/null --connect-timeout 5 -s -w %{http_code}  ${HEALTH_CHECK_URL}`
            if [ "$?" != "0" ]; then
               echo -n -e "\rapplication not started"
            else
                echo "code is $status_code"
                if [ "$status_code" == "200" ];then
                    break
                fi
            fi
            sleep 1
            ((exptime++))

            echo -e "\rWait app to pass health check: $exptime..."

            if [ $exptime -gt ${APP_START_TIMEOUT} ]; then
                echo 'app start failed'
               exit 1
            fi
        done
    echo "check ${HEALTH_CHECK_URL} success"
}
start_application() {
    echo "starting java process"
    bash /www/tomcat/bin/startup.sh
    echo "started java process"
}

stop_application() {
   checkjavapid=`ps -ef | grep java | grep ${APP_NAME} | grep -v grep |grep -v 'deploy.sh'| awk '{print$2}'`
   
   if [[ ! $checkjavapid ]];then
      echo -e "\rno java process"
      return
   fi

   echo "stop java process"
   times=60
   for e in $(seq 60)
   do
        sleep 3
        COSTTIME=$(($times - $e ))
        checkjavapid=`ps -ef | grep java | grep ${APP_NAME} | grep -v grep |grep -v 'deploy.sh'| awk '{print$2}'`
        if [[ $checkjavapid ]];then
            kill $checkjavapid
            echo -e  "\r        -- stopping java lasts `expr $COSTTIME` seconds."
        else
            echo -e "\rjava process has exited"
            break;
        fi
   done
   echo ""
}
start() {
    start_application
    health_check
}
stop() {
    stop_application
}
case "$ACTION" in
    start)
        start
    ;;
    stop)
        stop
    ;;
    restart)
        stop
        start
    ;;
    *)
        usage
    ;;
esac