BSD Jails
From Leo's Notes
Last edited on 21 July 2019, at 23:00.
Creating a new BSD Jail
Create the world:
# mkdir -p /usr/jail/<jail name>
# cd /usr/src
# make buildworld
# make installworld DESTDIR=/usr/jail/<jail name>
# make distribution DESTDIR=/usr/jail/<jail name>
# mount -t devfs devfs /usr/jail/<jail name>/dev
Set up the networking for this jail:
# ifconfig re0 10.1.1.21 netmask 255.255.255.0 alias
# cp /etc/resolv.conf /usr/jail/<jail name>/etc/
If you ever want to remove this alias from your host, run
# ifconfig re0 10.1.1.21 netmask 255.255.255.0 remove
Starting a Jail Manually
# jail -n <jail name> /usr/jail/<jail name> <jail name> 10.1.1.20 /bin/sh
Note that this is a one-time thing. If you want it persistent, continue reading on...
Starting Jails Automatically
To ensure the jail gets started on boot, add the following to your /etc/rc.conf file
jail_enable="YES" jail_jail_name_name="jail_name" jail_jail_name_hostname="jail_name.home.steamr.com" jail_jail_name_ip="10.1.1.20" jail_jail_name_devfs_enable="YES" jail_jail_name_rootdir="/usr/jail/jail_name" jail_jail_name_mount_enable="YES" jail_jail_name_fstab="/etc/jails/fstabs/jail_name" jail_jail_name_vnet_enable="YES"
Add to /etc/jails/fstabs/jail_name
/usr/src /usr/jail/jail_name/usr/src nullfs rw 0 0 /usr/ports /usr/jail/jail_name/usr/ports nullfs rw 0 0
Start the jail using the rc scripts
# /etc/rc.d/jail start jail_name
Managing Jails
# jls #get the jid
# jexec <jid> sh
jail# echo "enable_sshd=\"YES\"" >> /etc/rc.conf
jail# /etc/rc.d/sshd start