一、需求
centos6下面添加开机服务，例如开机启动supervisor服务，然后supervisor会负责拉起配置的进程，从而实现各种服务的开机重启。
二、原理需求
在centos6下面主要通过在/etc/init.d/下面添加服务脚本和chkconfig命令来完成添加启动服务
- 添加服务的启停脚本
如果需要开机启动服务，或者通过service命令控制服务，必须在/etc/init.d/下面有对应服务的启停脚本，如果我们的服务为supervisor，那么在/etc/init.d/下面对应的启停脚本就是supervisor，且具有执行权限。启停脚本个格式一般都是固定的，比如包括start、stop等函数，来用来对服务进行启动/关闭
如
#!/bin/bash
#
# supervisord This scripts turns supervisord on
#
# Author: Mike McGrath <[email protected]> (based off yumupdatesd)
# Jason Koppe <[email protected]> adjusted to read sysconfig,
# use supervisord tools to start/stop, conditionally wait
# for child processes to shutdown, and startup later
# Mikhail Mingalev <[email protected]> Merged
# redhat-init-jkoppe and redhat-sysconfig-jkoppe, and
# made the script "simple customizable".
# Brendan Maguire <[email protected]> Added OPTIONS to
# SUPERVISORCTL status call
#
# chkconfig: 345 83 04
#
# description: supervisor is a process control utility. It has a web based
# xmlrpc interface as well as a few other nifty features.
# Script was originally written by Jason Koppe <[email protected]>.
#
# usage：rename this script to ‘supervisor‘ and put it to directory /etc/init.d/
# source function library
. /etc/rc.d/init.d/functions
# service strips all environment variables but TERM, PATH and LANG,
# so we need export those variables explicitly.
# see http://unix.stackexchange.com/questions/44370/how-to-make-unix-service-see-environment-variables
export HOSTNAME
export USER=hadoop2
# hadoop‘s environment variables
. /home/hadoop2/.bashrc
SUPERVISORD=/usr/bin/supervisord
SUPERVISORCTL=/usr/bin/supervisorctl
PIDFILE=/tmp/supervisord.pid
LOCKFILE=/tmp/supervisord
OPTIONS="-c /usr/local/supervisor/supervisord.conf"
# unset this variable if you don‘t care to wait for child processes to shutdown before removing the $LOCKFILE-lock
WAIT_FOR_SUBPROCESSES=yes
# remove this if you manage number of open files in some other fashion
ulimit -n 96000
RETVAL=0
running_pid()
{
# Check if a given process pid‘s cmdline matches a given name
pid=$1
name=$2
[ -z "$pid" ] && return 1
[ ! -d /proc/$pid ] && return 1
(cat /proc/$pid/cmdline | tr "\000" "\n"|grep -q $name) || return 1
return 0
}
running()
{
# Check if the process is running looking at /proc
# (works for all users)
# No pidfile, probably no daemon present
[ ! -f "$PIDFILE" ] && return 1
# Obtain the pid and check it against the binary name
pid=`cat $PIDFILE`
running_pid $pid $SUPERVISORD || return 1
return 0
}
is_root()
{
current_user=`whoami`
if [ "x"$current_user == "xroot" ];then
echo "current_user is:"$current_user
return 0
elif [ "x"$USER == "xroot" ];then
echo "USER is:"$USER
return 0
else
return 1
fi
}
start() {
echo "Starting supervisord: "
if running ; then
echo "ALREADY STARTED"
return 1
fi
if is_root ;then
# start supervisord with options from sysconfig (stuff like -c)
su hadoop2 -c "$SUPERVISORD $OPTIONS"
# show initial startup status
su hadoop2 -c "$SUPERVISORCTL $OPTIONS status"
# only create the subsyslock if we created the PIDFILE
su hadoop2 -c "[ -e $PIDFILE ] && touch $LOCKFILE"
else
# start supervisord with options from sysconfig (stuff like -c)
$SUPERVISORD $OPTIONS
# show initial startup status
$SUPERVISORCTL $OPTIONS status
# only create the subsyslock if we created the PIDFILE
[ -e $PIDFILE ] && touch $LOCKFILE
fi
}
stop() {
echo -n "Stopping supervisord: "
if is_root ;then
su hadoop2 -c "$SUPERVISORCTL $OPTIONS shutdown"
else
$SUPERVISORCTL $OPTIONS shutdown
fi
if [ -n "$WAIT_FOR_SUBPROCESSES" ]; then
echo "Waiting roughly 60 seconds for $PIDFILE to be removed after child processes exit"
for sleep in 2 2 2 2 4 4 4 4 8 8 8 8 last; do
if [ ! -e $PIDFILE ] ; then
echo "Supervisord exited as expected in under $total_sleep seconds"
break
else
if [[ $sleep -eq "last" ]] ; then
echo "Supervisord still working on shutting down. We‘ve waited roughly 60 seconds, we‘ll let it do its thing from here"
return 1
else
sleep $sleep
total_sleep=$(( $total_sleep + $sleep ))
fi
fi
done
fi
# always remove the subsys. We might have waited a while, but just remove it at this point.
rm -f $LOCKFILE
}
restart() {
stop
start
}
case "$1" in
start)
start
RETVAL=$?
;;
stop)
stop
RETVAL=$?
;;
restart|force-reload)
restart
RETVAL=$?
;;
reload)
$SUPERVISORCTL $OPTIONS reload
RETVAL=$?
;;
condrestart)
[ -f $LOCKFILE ] && restart
RETVAL=$?
;;
status)
$SUPERVISORCTL $OPTIONS status
if running ; then
RETVAL=0
else
RETVAL=1
fi
;;
*)
echo $"Usage: $0 {start|stop|status|restart|reload|force-reload|condrestart}"
exit 1
esac
exit $RETVAL
一些坑
- 开机启动的用户身份是root，可我们需要是其他用户身份，比如hadoop启动服务
使用su user -c
"cmd_here" 来执行服务启动，可以用你希望的用户身份启动服务 - 环境变量读取不到，例如JAVA_HOME等,造成服务启动不成功
这主要是service系统在执行时，会strip掉除TERM、PATH等以外所以环境变量。解决的办法是在启停服务脚本中export需要的环境变量 - 添加或启动service时，提示No such file or
directory
可能是你在windows下面编辑文件，然后上传到linux，因为windows的许多编辑器会在末尾多加换行。详细解决方案，看这里1、运行检查
cat -v /etc/init.d/your_init_script
2.解决
sed -i -e ‘s/\r//g‘ /etc/init.d/your_init_script
时间： 2024-10-24 09:44:24