If you’ve ever needed to spin up a clean, minimal Linux VM for testing or local automation — and got tired of clicking through the VirtualBox GUI — this guide is for you.

We’ll walk through how to use HashiCorp Packer and VirtualBox to automatically create a Rocky Linux 8.10 image, ready to boot and use — no Vagrant, no fluff.

What You’ll Need

• Packer installed
• VirtualBox installed
• Rocky Linux 8.10 ISO link (we use minimal)
• Basic understanding of Linux + VirtualBox

Project Structure

packer-rocky/
├── http/
│   └── ks.cfg       # Kickstart file for unattended install
├── rocky.pkr.hcl    # Main Packer config

Step 1: Create the Kickstart File (http/ks.cfg)

install
cdrom
lang en_US.UTF-8
keyboard us
network --bootproto=dhcp
rootpw packer
firewall --disabled
selinux --permissive
timezone UTC
bootloader --location=mbr
text
skipx
zerombr

# Partition disk
clearpart --all --initlabel
part /boot --fstype="xfs" --size=1024
part pv.01 --fstype="lvmpv" --grow
volgroup vg0 pv.01
logvol / --vgname=vg0 --fstype="xfs" --size=10240 --name=root
logvol swap --vgname=vg0 --size=4096 --name=swap

reboot

%packages --ignoremissing
@core
@base
%end

%post
# Post-install steps can be added here
%end

Step 2: Create the Packer HCL Template (rocky.pkr.hcl)

packer {
  required_plugins {
    virtualbox = {
      version = ">= 1.0.5"
      source  = "github.com/hashicorp/virtualbox"
    }
  }
}

source "virtualbox-iso" "rocky" {
  iso_url                 = "https://download.rockylinux.org/pub/rocky/8/isos/x86_64/Rocky-8.10-x86_64-minimal.iso"
  iso_checksum            = "2c735d3b0de921bd671a0e2d08461e3593ac84f64cdaef32e3ed56ba01f74f4b"
  guest_os_type           = "RedHat_64"
  memory                  = 2048
  cpus                    = 2
  disk_size               = 40000
  vm_name                 = "rocky-8"
  headless                = false
  guest_additions_mode    = "disable"
  boot_command            = [" inst.text inst.ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/ks.cfg"]
  http_directory          = "http"
  ssh_username            = "root"
  ssh_password            = "packer"
  ssh_timeout             = "20m"
  shutdown_command        = "shutdown -P now"
  vboxmanage = [
    ["modifyvm", "{{.Name}}", "--vram", "32"],
    ["modifyvm", "{{.Name}}", "--vrde", "off"],
    ["modifyvm", "{{.Name}}", "--ioapic", "off"],
    ["modifyvm", "{{.Name}}", "--pae", "off"],
    ["modifyvm", "{{.Name}}", "--nested-hw-virt", "on"]
  ]
}

build {
  sources = ["source.virtualbox-iso.rocky"]
}

Step 3: Run the Build

cd packer-rocky
packer init .
packer build .

Packer will:

1. Download and boot the ISO in VirtualBox
2. Serve the ks.cfg file over HTTP
3. Automatically install Rocky Linux
4. Power off the machine once complete

Result

You now have a fully installed Rocky Linux 8.10 image in VirtualBox — no manual setup required.