Linux 添加Service服务详解

Linux 添加Service服务详解

网址：http://cwtea.blog.51cto.com/4500217/842002/

软件安装成服务过程详解：

service httpd restart

由三部分组成service(服务)、httpd（程序名）、restart（相关命令）少一不可

service: 是系统已经定义可的。无需更改。默认会查找/etc/init.d/* 

httpd: 程序名这个是已经确定的。

restart: 相关命令，如start 这个是控制程序走向。

 

那么非常明确的一个服务需要的流程:

1、程序是可执行程序

2、位置需放在/etc/init.d/目录下

3、相关命令，这个由程序本身决定（有没有指定）。

3.1 如果是已经有相关命令的，那么文件直接拷贝到/etc/init.d目录下，并给矛可执行权限。

3.2 如果是没有定义，那我们需要写一个脚本。并定义好相关命令。

 

一、看一个sshd实例，来帮助我们了解整体过程。

# vim /etc/init.d/sshd

----------sshd start------------------

#!/bin/bash

#

# Init file for OpenSSH server daemon

#

# chkconfig: 2345 55 25

# description: OpenSSH server daemon

#

# processname: sshd

# config: /etc/ssh/ssh_host_key

# config: /etc/ssh/ssh_host_key.pub

# config: /etc/ssh/ssh_random_seed

# config: /etc/ssh/sshd_config

# pidfile: /var/run/sshd.pid

 

# source function library

. /etc/rc.d/init.d/functions

 

# pull in sysconfig settings

[ -f /etc/sysconfig/sshd ] && . /etc/sysconfig/sshd

 

RETVAL=0

prog="sshd"

 

# Some functions to make the below more readable

KEYGEN=/usr/bin/ssh-keygen

SSHD=/usr/sbin/sshd

RSA1_KEY=/etc/ssh/ssh_host_key

RSA_KEY=/etc/ssh/ssh_host_rsa_key

DSA_KEY=/etc/ssh/ssh_host_dsa_key

PID_FILE=/var/run/sshd.pid

 

runlevel=$(set -- $(runlevel); eval "echo \$$#" )

 

do_rsa1_keygen() {

if [ ! -s $RSA1_KEY ]; then

echo -n $"Generating SSH1 RSA host key: "

if $KEYGEN -q -t rsa1 -f $RSA1_KEY -C '' -N '' >&/dev/null; then

chmod 600 $RSA1_KEY

chmod 644 $RSA1_KEY.pub

if [ -x /sbin/restorecon ]; then

    /sbin/restorecon $RSA1_KEY.pub

fi

success $"RSA1 key generation"

echo

else

failure $"RSA1 key generation"

echo

exit 1

fi

fi

}

 

do_rsa_keygen() {

if [ ! -s $RSA_KEY ]; then

echo -n $"Generating SSH2 RSA host key: "

if $KEYGEN -q -t rsa -f $RSA_KEY -C '' -N '' >&/dev/null; then

chmod 600 $RSA_KEY

chmod 644 $RSA_KEY.pub

if [ -x /sbin/restorecon ]; then

    /sbin/restorecon $RSA_KEY.pub

fi

success $"RSA key generation"

echo

else

failure $"RSA key generation"

echo

exit 1

fi

fi

}

 

do_dsa_keygen() {

if [ ! -s $DSA_KEY ]; then

echo -n $"Generating SSH2 DSA host key: "

if $KEYGEN -q -t dsa -f $DSA_KEY -C '' -N '' >&/dev/null; then

chmod 600 $DSA_KEY

chmod 644 $DSA_KEY.pub

if [ -x /sbin/restorecon ]; then

    /sbin/restorecon $DSA_KEY.pub

fi

success $"DSA key generation"

echo

else

failure $"DSA key generation"

echo

exit 1

fi

fi

}

 

do_restart_sanity_check()

{

$SSHD -t

RETVAL=$?

if [ ! "$RETVAL" = 0 ]; then

failure $"Configuration file or keys are invalid"

echo

fi

}

 

start()

{

# Create keys if necessary

do_rsa1_keygen

do_rsa_keygen

do_dsa_keygen

cp -af /etc/localtime /var/empty/sshd/etc

 

echo -n $"Starting $prog: "

$SSHD $OPTIONS && success || failure

RETVAL=$?

[ "$RETVAL" = 0 ] && touch /var/lock/subsys/sshd

echo

}

 

stop()

{

echo -n $"Stopping $prog: "

if [ -n "`pidfileofproc $SSHD`" ] ; then

    killproc $SSHD

else

    failure $"Stopping $prog"

fi

RETVAL=$?

# if we are in halt or reboot runlevel kill all running sessions

# so the TCP connections are closed cleanly

if [ "x$runlevel" = x0 -o "x$runlevel" = x6 ] ; then

    killall $prog 2>/dev/null

fi

[ "$RETVAL" = 0 ] && rm -f /var/lock/subsys/sshd

echo

}

 

reload()

{

echo -n $"Reloading $prog: "

if [ -n "`pidfileofproc $SSHD`" ] ; then

    killproc $SSHD -HUP

else

    failure $"Reloading $prog"

fi

RETVAL=$?

echo

}

 

case "$1" in

start)

start

;;

stop)

stop

;;

restart)

stop

start

;;

reload)

reload

;;

condrestart)

if [ -f /var/lock/subsys/sshd ] ; then

do_restart_sanity_check

if [ "$RETVAL" = 0 ] ; then

stop

# avoid race

sleep 3

start

fi

fi

;;

status)

status -p $PID_FILE openssh-daemon

RETVAL=$?

;;

*)

echo $"Usage: $0 {start|stop|restart|reload|condrestart|status}"

RETVAL=1

esac

exit $RETVAL

--------------sshd stop---------------------------

煮酒品茶：可以看出来，一些判断语句和一些执行路径。以即最下方的获取相关命令并给予相关执行命令。瞧，一个服务的添加就这么简单。测试吧

过程如下：

 

[root@localhost test]# service test restart

test: unrecognized service

[root@localhost test]# cp test /etc/init.d/

[root@localhost test]# ll /etc/init.d/ |grep test

-rwxr-xr-x 1 root root    19 Apr 23 11:37 test

[root@localhost test]# service test restart

hello world

 

#vim /etc/init.d/test

-------------------test start---------------

 

case "$1" in

start)

echo -n "Starting test: "

 ~/test/test

echo -n "start is OK"

  ;;

stop)

echo -n "Shutting stop test: "

killall test

echo -n "stop is OK"

  ;;

esac

exit

-------------stop-------------------

[root@localhost test]# service test start

Starting test: hello world

start is OK[root@localhost test]# service test stop

Shutting stop test: test: no process killed

 

煮酒品茶：很简单的的可以理解，先是放到service能找的着的地方，然后再给它判断命令如果是start就写文件正在启动test中，启动完后给一个启动ok的。同理结束直接kill掉他的进程就好了。其它的自由发挥比如：reload、restart等。