How to Use `bsdinstall` for Automated Deployments on FreeBSD

Introduction

bsdinstall is the default installer for FreeBSD, offering both interactive and automated installation methods. While manual installations are useful for one-time setups, automation is essential for deploying FreeBSD efficiently across multiple systems. This guide will walk you through the process of using bsdinstall for automated deployments.

Understanding bsdinstall

bsdinstall is a modular installation utility that can be customized for unattended installations. It relies on installation scripts to configure partitions, install the base system, and apply post-installation configurations.

Automation with bsdinstall is achieved using a scripted installation (commonly called an install script or answer file). By preparing a suitable configuration file, you can automate:

• Disk partitioning
• Package installations
• Network configurations
• User account setup
• System hardening

Setting Up an Automated Installation

1. Preparing the Installation Medium

Before automating FreeBSD installations, you need an installation medium. This can be a USB flash drive, CD/DVD, or a network-based PXE boot system.

To create a bootable FreeBSD installation medium:

fetch https://download.freebsd.org/releases/amd64/13.2-RELEASE/FreeBSD-13.2-RELEASE-amd64-memstick.img
dd if=FreeBSD-13.2-RELEASE-amd64-memstick.img of=/dev/da0 bs=1M status=progress

Replace /dev/da0 with the correct device for your USB drive.

2. Creating the Automated Installation Script

FreeBSD’s automated installation uses a script containing predefined settings. Create a script file, e.g., install.cfg, and place it in a location where the installer can access it (e.g., a USB drive, PXE server, or an HTTP location).

A basic install.cfg example:

#!/bin/sh
PARTITIONS="ada0 GPT ZFS"
DISTRIBUTIONS="base.txz kernel.txz"
ROOT_PASSWORD="changeme"

#!/bin/sh
# Disk partitioning
bsdinstall partedit ada0 GPT ZFS

# System configuration
bsdinstall script <<EOF
set -e
# Set hostname
hostname="freebsd-host"
# Enable SSH service
sysrc sshd_enable="YES"
# Set root password
echo "root:\$ROOT_PASSWORD" | chpasswd
# Add a user
pw useradd -n user -c "Admin User" -m -s /bin/sh -G wheel
# Enable sudo for wheel users
echo "%wheel ALL=(ALL) NOPASSWD: ALL" > /usr/local/etc/sudoers.d/wheel
EOF

3. Running the Automated Installation

To launch an automated installation, boot the system from the FreeBSD installation medium and pass the script as an argument:

bsdinstall script /mnt/install.cfg

Alternatively, if using PXE, configure the PXE server to provide the script via HTTP or NFS.

4. Post-Installation Customization

Once the system is installed, additional setup may be necessary. This can include installing packages, applying security hardening, or configuring network settings. You can create a post-installation script (postinstall.sh) and place it in /usr/local/bin/ for execution after the first boot.

Example:

#!/bin/sh
# Update FreeBSD packages
pkg update && pkg upgrade -y
# Install essential packages
pkg install -y vim git sudo
# Enable firewall
sysrc pf_enable="YES"
service pf start

Make the script executable:

chmod +x /usr/local/bin/postinstall.sh

Add to /etc/rc.local for execution on first boot:

echo "/usr/local/bin/postinstall.sh" >> /etc/rc.local

Automating Deployment with PXE Boot

For large-scale deployments, using a PXE boot server allows fully automated installations over the network.

1. Setting Up a PXE Boot Server

PXE booting requires:

• A DHCP server (to provide IP and boot information)
• A TFTP server (to serve the bootloader)
• An NFS or HTTP server (to serve installation files)

Configure DHCP (ISC DHCP Server Example)

Edit /etc/dhcpd.conf:

subnet 192.168.1.0 netmask 255.255.255.0 {
    range 192.168.1.100 192.168.1.200;
    option routers 192.168.1.1;
    filename "pxeboot";
    next-server 192.168.1.10;
}

Restart DHCP:

service isc-dhcpd restart

Configure TFTP

Install and enable TFTP:

pkg install tftp-hpa
sysrc tftpd_enable="YES"
service tftpd start

Copy FreeBSD PXE files to TFTP root (/tftpboot):

cp -r /mnt/usr/freebsd-dist/ /tftpboot/
cp /boot/pxeboot /tftpboot/

Configure NFS/HTTP for Installation Files

Set up an NFS export:

echo "/mnt/freebsd-dist -ro -maproot=root" >> /etc/exports
service nfsd restart

Modify the install.cfg script to fetch files from the network:

bsdinstall script "http://192.168.1.10/install.cfg"

Troubleshooting Common Issues

1. bsdinstall Script Not Running

Ensure the script file is correctly formatted and accessible. Check with:

file /mnt/install.cfg
cat -v /mnt/install.cfg | less

If using PXE, verify DHCP and TFTP configurations:

dhcpd -t -cf /etc/dhcpd.conf
tftp -v 192.168.1.10 -c get pxeboot

2. Disk Partitioning Errors

Check available disks with:

gpart show

Ensure the partitioning scheme in install.cfg matches the system’s requirements.

3. Network Issues

Ensure that the network is correctly configured before fetching additional packages or scripts.

ifconfig -a
dhclient em0
ping google.com

Conclusion

Automating FreeBSD installations with bsdinstall significantly reduces deployment time and ensures consistency across multiple installations. By leveraging scripted installations and PXE booting, system administrators can deploy FreeBSD efficiently in diverse environments. Mastering these automation techniques allows for scalable and reproducible system setups, making FreeBSD a powerful choice for enterprise and server environments.