This document will describe the setup of jail(8) and how-to configure all applications to work properly within a jail(8). It has the following design criteria/assumptions:
* /usr/ports is shared throughout all installations (so are all the configuration for the ports then) and every system build all ports himself.
* my sample jail is called {{{pzwet}}} and is located in file:/usr/jail/pzwet   

Important: Your jail server should not run ''any'' public facing services which does 'wildcard' binding to IP addresses, else it will 'claim' the service before your jail can take it.
Tip: Jails does '''NOT''' have a local loopback device, so you will need to use UNIX sockets on places you would normally use the loopback address.

First make sure to install the jail using the [http://www.freebsd.org/doc/handbook/jails.html method in the handbook]
pzwet# cat <<EOF >> /etc/rc.conf
shd_enable="YES"
syslogd_flags="-ss"

sendmail_enable="YES"
spamass_milter_enable="YES"
spamass_milter_localflags="-i 78.46.112.168,0.0.0.0 -r -1 -- -U /var/run/spamd.sock"

spamd_enable="YES"
spamd_flags="--socketpath=/var/run/spamd.sock --nouser-config --username=nobody"

# saving entropy bits is not useful within jails, as your host will do handle this.
entropy_dir="NO" 
# Get some jitter in your cron runs to make sure the does not all run at time same time. Do NOT use if you rely on having your process to start at 'exact' that time.
cron_flags="-J10"
EOF

pzwet# make -C /usr/ports/security/sudo WITH_INSULTS=yes BATCH=yes install clean
pzwet# make -C /usr/ports/devel/subversion WITH_MOD_DAV_SVN=yes APACHE_VERSION=22 BATCH=yes install clean
pzwet# make -C /usr/ports/ports-mgmt/portaudit BATCH=yes install clean; /usr/local/sbin/portaudit -Fda
pzwet# make -C /usr/ports/editors/vim-lite BATCH=yes install clean


Update port INDEX tree and report on pending upgrades every Saturday:
pzwet# echo '0       3       *       *       sat     root /usr/sbin/portsnap -I  cron update && /usr/sbin/pkg_version -vIL=' >> /etc/crontab