使用/etc/rc.d/rc.local配置程序在Linux系统启动时自动启动

在Linux系统上工作时，我们可能经常需要在系统启动时执行一项任务，虽然有Systemd，Supervisor等应用程序程序自动启动的管理模块，对比起来，还是在rc.local里调用一下shell脚本还是最简便的方式。

由于操作系统默认没有给rc.local文件可执行权限，所以我们首先我们给/etc/rc.d/rc.local授予执行权限（切记！切记！切记！），如下所示。然后在/etc/rc.local中写入需要执行的启动命令，当Linux重启之后就会自动执行其中的命令，实现服务跟随系统自动重启。

# chmod +x /etc/rc.d/rc.local

一、接下来我们以启动metabase.jar为例创建一个start.sh脚本

#!/bin/sh
APP_HOME=$(cd "$(dirname "$0")";pwd)
APP_EXEC_JAR="metabase.jar"
PIDFILE="$APP_HOME/pid"
export MB_DB_TYPE=postgres
export MB_DB_DBNAME=metabase
export MB_DB_PORT=5432
export MB_DB_USER=dbuser
export MB_DB_PASS=dbpass
export MB_DB_HOST=192.168.0.0

checkRunning(){
    if [ -f "$PIDFILE" ]; then
       if  [ -z "`cat $PIDFILE`" ];then
        echo "ERROR: Pidfile '$PIDFILE' exists but contains no pid"
        return 2
       fi
       PID="`cat $PIDFILE`"
       RET="`ps -p $PID|grep java`"
       if [ -n "$RET" ];then
         return 0;
       else
         return 1;
       fi
    else
         return 1;
    fi
}

if ( checkRunning );then
    PID=`cat $PIDFILE`
    echo "INFO: Process with pid '$PID' is already running"
    exit 0
fi

java -server  -jar $APP_EXEC_JAR > nohup 2>&1 &

echo $! > "$APP_HOME/pid";
PID="`cat $PIDFILE`"

echo "INFO: Starting - Process $PID"

二、将metabase的启动脚本添加到/etc/rc.d/rc.local

#!/bin/bash
# THIS FILE IS ADDED FOR COMPATIBILITY PURPOSES
#
# It is highly advisable to create own systemd services or udev rules
# to run scripts during boot instead of using this file.
#
# In contrast to previous versions due to parallel execution during boot
# this script will NOT be run after all other services.
#
# Please note that you must run 'chmod +x /etc/rc.d/rc.local' to ensure
# that this script will be executed during boot.

touch /var/lock/subsys/local

/opt/metabase/start.sh

至此，配置完成，系统重启后会自动通过/opt/metabase/start.sh脚本启动metabase服务。务必不要忘记给rc.local、start.sh添加可执行权限