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/apache22 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.
Now that FreeBSD includes rc.d, configuration of application startup has become easier, and more featureful. Using the key words discussed in the rc.d section, applications may now be set to start after certain other services for example DNS; may permit extra flags to be passed through rc.conf in place of hard coded flags in the start up script, etc. A basic script may look similar to the following:
#!/bin/sh
#
# PROVIDE: utility
# REQUIRE: DAEMON
# KEYWORD: shutdown
. /etc/rc.subr
name=utility
rcvar=utility_enable
command="/usr/local/sbin/utility"
load_rc_config $name
#
# DO NOT CHANGE THESE DEFAULT VALUES HERE
# SET THEM IN THE /etc/rc.conf FILE
#
utility_enable=${utility_enable-"NO"}
pidfile=${utility_pidfile-"/var/run/utility.pid"}
run_rc_command "$1"
This script will ensure that the provided utility will be started after the DAEMON pseudo-service. It also provides a method for setting and tracking the PID, or process ID file.
This application could then have the following line placed in /etc/rc.conf:
utility_enable="YES"
This method also allows for easier manipulation of the command line arguments, inclusion of the default functions provided in /etc/rc.subr, compatibility with the rcorder(8) utility and provides for easier configuration via rc.conf.
Other services, such as POP3 server daemons, IMAP, etc. could be started using inetd(8). This involves installing the service utility from the Ports Collection with a configuration line added to /etc/inetd.conf, or by uncommenting one of the current configuration lines. Working with inetd and its configuration is described in depth in the inetd section.
In some cases it may make more sense to use the cron(8) daemon to start system services. This approach has a number of advantages because cron runs these processes as the crontab's file owner. This allows regular users to start and maintain some applications.
The cron utility provides a unique feature, @reboot, which may be used in place of the time specification. This will cause the job to be run when cron(8) is started, normally during system initialization.