Linux服务开机自启动使用示例

Posted 2020-12-04

本文以redis服务为例，介绍了两种服务自启动的方法service,systemctl使用示例

1.修改redis.conf，允许后台运行
daemonize no 改为 daemonize yes

2.使用service命令
1)编写启动shell脚本，命名为redis
redis文件代码如下：

#!/bin/sh
#Configurations injected by install_server below....

EXEC=/home/shijingjing/redis-4.0.2/src/redis-server   # redis-server的路径
CLIEXEC=/home/shijingjing/redis-4.0.2/src/redis-cli   # redis-cli的路径
PIDFILE=/var/run/redis_6379.pid  # redis.conf里有这个参数，将其复制过来
CONF="/home/shijingjing/redis-4.0.2/redis.conf"  # redis.conf的路径
REDISPORT="6379"  # 端口
###############
# SysV Init Information
# chkconfig: - 58 74
# description: redis is the redis daemon.
### BEGIN INIT INFO
# Provides: redis
# Required-Start: $network $local_fs $remote_fs
# Required-Stop: $network $local_fs $remote_fs
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Should-Start: $syslog $named
# Should-Stop: $syslog $named
# Short-Description: start and stop redis
# Description: Redis daemon
### END INIT INFO


case "$1" in
    start)
        if [ -f $PIDFILE ]
        then
            echo "$PIDFILE exists, process is already running or crashed"
        else
            echo "Starting Redis server..."
            $EXEC $CONF
        fi
        ;;
    stop)
        if [ ! -f $PIDFILE ]
        then
            echo "$PIDFILE does not exist, process is not running"
        else
            PID=$(cat $PIDFILE)
            echo "Stopping ..."
            $CLIEXEC -p $REDISPORT shutdown
            while [ -x /proc/${PID} ]
            do
                echo "Waiting for Redis to shutdown ..."
                sleep 1
            done
            echo "Redis stopped"
        fi
        ;;
    status)
        PID=$(cat $PIDFILE)
        if [ ! -x /proc/${PID} ]
        then
            echo 'Redis is not running'
        else
            echo "Redis is running ($PID)"
        fi
        ;;
    restart)
        $0 stop
        $0 start
        ;;
    *)
        echo "Please use start, stop, restart or status as first argument"
        ;;
esac

将redis文件放入/etc/init.d文件夹中，也可以直接将安装目录下utils/redis_init_script文件拷贝到该目录下

更改文件为可执行

chmod +x redis

2)将执行文件放入，移除开机自启动

update-rc.d redis defaults
update-rc.d redis remove

3)手动启动关闭redis

/etc/init.d/redis start
/etc/init.d/redis stop
/etc/init.d/redis restart

3.使用systemctl命令
1)编写.service文件,redis.service

[Unit]
Description=redis

[Service]
PIDFile=/var/run/redis.pid
ExecStart=/home/shijingjing/redis-4.0.2/src/redis-server
Restart=on-failure
RestartSec=42s

[Install]
WantedBy=multi-user.target

将redis.service放入/etc/systemd/system文件夹下

2)将服务加入，移除开机自启动

systemctl enable redis
systemctl disable redis

3)手动启动关闭redis

systemctl start redis
systemctl stop redis
systemctl restart redis

4.service和systemctl比较
systemd兼容service，更为的强大
编写服务启动脚本也更简洁，service需要编写完整的shell脚本,systemd只需要配置执行文件，pid文件路径，剩下的交给systemd去做就可以了