11.5 各種 Services 的啟動方式

Many users choose to install third party software on FreeBSD from the Ports Collection. In many of these situations it may be necessary to configure the software in a manner which will allow it to be started upon system initialization. Services, such as mail/postfix or www/apache13 are just two of the many software packages which may be started during system initialization. This section explains the procedures available for starting third party software.

In FreeBSD, most included services, such as cron(8), are started through the system start up scripts. These scripts may differ depending on FreeBSD or vendor version; however, the most important aspect to consider is that their start up configuration can be handled through simple startup scripts.

Before the advent of rc.d, applications would drop a simple start up script into the /usr/local/etc/rc.d directory which would be read by the system initialization scripts. These scripts would then be executed during the latter stages of system start up.

While many individuals have spent hours trying to merge the old configuration style into the new system, the fact remains that some third party utilities still require a script simply dropped into the aforementioned directory. The subtle differences in the scripts depend whether or not rc.d is being used. Prior to FreeBSD 5.1 the old configuration style is used and in almost all cases a new style script would do just fine.

While every script must meet some minimal requirements, most of the time these requirements are FreeBSD version agnostic. Each script must have a .sh extension appended to the end and every script must be executable by the system. The latter may be achieved by using the chmod command and setting the unique permissions of 755. There should also be, at minimal, an option to start the application and an option to stop the application.

The simplest start up script would probably look a little bit like this one:

#!/bin/sh
echo -n ' utility'

case "$1" in
start)
        /usr/local/bin/utility
        ;;
stop)
        kill -9 `cat /var/run/utility.pid`
        ;;
*)
        echo "Usage: `basename $0` {start|stop}" >&2
        exit 64
        ;;
esac

exit 0

This script provides for a stop and start option for the application hereto referred simply as utility.

Could be started manually with:

# /usr/local/etc/rc.d/utility.sh start

While not all third party software requires the line in rc.conf, almost every day a new port will be modified to accept this configuration. Check the final output of the installation for more information on a specific application. Some third party software will provide start up scripts which permit the application to be used with rc.d; although, this will be discussed in the next section.

#!/bin/sh
#
# PROVIDE: utility
# REQUIRE: DAEMON
# KEYWORD: shutdown

#
# DO NOT CHANGE THESE DEFAULT VALUES HERE
# SET THEM IN THE /etc/rc.conf FILE
#
utility_enable=${utility_enable-"NO"}
utility_flags=${utility_flags-""}
utility_pidfile=${utility_pidfile-"/var/run/utility.pid"}

. /etc/rc.subr

name="utility"
rcvar=`set_rcvar`
command="/usr/local/sbin/utility"

load_rc_config $name

pidfile="${utility_pidfile}"

start_cmd="echo \"Starting ${name}.\"; /usr/bin/nice -5 ${command} ${utility_flags} ${command_args}"

run_rc_command "$1"

utility_enable="YES"