jailconf-builder

README

jailconf-builder

jailconf-builder is a CLI tool for managing FreeBSD jails using the standard jail.conf(5) configuration.

Back around 2013, when I was working with jail.conf(5) on FreeBSD 9.x, I wished there was an include option to improve usability. Recently, I revisited jail.conf(5) and discovered that the include option is indeed implemented. This discovery led to the development of this jailconf-builder, which uses the standard features of the jail system.

Note

This is a CLI tool for creating jail environments using jail.conf(5). For jail operations, please use commands such as jail -c <jail_name> , jail -r <jail_name> , jls , and jexec 1 /bin/tcsh.

Features

• Initialize jailconf-builder environment
• Create new jails with VNET support
• Delete jails with safety checks
• Download FreeBSD base system for jails

Directory Structure

/etc/jail.conf.d/                # Jail configuration files (FreeBSD standard)
/var/jails/                      # Jail root directories
/var/db/jailconf-builder/base/   # FreeBSD base systems

Installation

Build the tool:

$ GOOS=freebsd GOARCH=amd64 CGO_ENABLED=0 go build -a -ldflags '-extldflags "-static"' -o jailconf-builder

Network Setup

Before using jailconf-builder , you need to set up the network environment. Run the following commands as root:

Create and configure the bridge interface:

# ifconfig bridge create
# ifconfig bridge0 inet 192.168.2.1/24
# ifconfig bridge0 up

Enable PF (Packet Filter):

# cat << EOF >> /etc/rc.conf
pf_enable="YES"
pf_flags=""
EOF

Configure NAT:

# echo 'nat on vtnet0 from 192.168.2.0/24 to any -> (vtnet0)' > /etc/pf.conf
# echo 'pass all' >> /etc/pf.conf

Enable IP forwarding:

# sysctl net.inet.ip.forwarding=1

Start the PF service:

# service pf start

Note: Replace vtnet0 with your actual network interface name if different.

For more information on configuring PF, refer to the FreeBSD Handbook section on Firewalls.

Usage

Initialize

Before using jailconf-builder , you need to initialize the environment:

$ sudo jailconf-builder init

This command:

• Confirms /etc/jail.conf.d directory exists
• Adds include directive to /etc/jail.conf
• Creates /var/jails directory
• Creates /var/db/jailconf-builder/base directory

Download FreeBSD Base System

To download the FreeBSD base system for a specific version:

$ sudo jailconf-builder dl-base -s <URL_to_base.txz>

Example:

$ sudo jailconf-builder dl-base -s https://download.freebsd.org/releases/amd64/14.3-RELEASE/base.txz

Create a Jail

To create a new jail:

$ sudo jailconf-builder create -name <jail_name> -version <FreeBSD_version>

Example:

$ sudo jailconf-builder create -name myjail -version 14.3-RELEASE

IP address and epair number are automatically assigned.

To list existing jails, use:

$ ls /etc/jail.conf.d/

Delete a Jail

To delete a jail:

$ sudo jailconf-builder delete -name <jail_name>

This will prompt for confirmation. To skip the confirmation, use the -f flag:

$ sudo jailconf-builder delete -name <jail_name> -f

License

This project is licensed under the MIT License.