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Kubernetes-ready Ubuntu Vagrant Box with OS-level optimizations. Supports 24.04 LTS (Noble Numbat, default) and 26.04 LTS (Resolute Raccoon, kernel Linux 7.0).

Vagrant Cloud (v1.1.0):

• 24.04 ext4: dasomel/ubuntu-24.04-ext4 / xfs: dasomel/ubuntu-24.04-xfs
• 26.04 ext4: dasomel/ubuntu-26.04-ext4 / xfs: dasomel/ubuntu-26.04-xfs

24.04 vs 26.04

	24.04 LTS (Noble Numbat)	26.04 LTS (Resolute Raccoon)
Kernel	6.8	7.0
init / cgroup	systemd 255, cgroup v2 default	systemd 259, cgroup v1 removed (v2-only)
Container runtime	containerd 1.7	containerd 2.2 / runc 1.4
Crypto	TLS 1.2+	Post-quantum default (OpenSSL 3.5 / OpenSSH 10.2)
Core utilities	GNU coreutils, sudo	partial Rust rewrite (uutils, sudo-rs)
Choose when	Maximum stability (default)	Latest LTS, kernel 7.0 features

K8s note: 26.04 is cgroup v2-only — set SystemdCgroup=true for kubelet/containerd (see K8s Post-Install). Both lines are tuned identically for Kubernetes. Full comparison: migration notes.

Features

• Base OS: Ubuntu 24.04 LTS or 26.04 LTS Cloud Image
• Multi-Architecture: AMD64, ARM64
• Multi-Provider: VirtualBox, VMware Fusion
• Filesystem Selection: ext4 (default) or xfs
• K8s Ready: OS tuning for Kubernetes (K8s not included)
• 1TB Disk: Large disk with thin provisioning (ext4 ~2.2GB, xfs ~3.4GB)
• Auto-Extension: Disk auto-extends on boot (partition → PV → LV → filesystem)

Build Matrix

Provider	AMD64	ARM64	Notes
VirtualBox	✅	✅	VirtualBox 7.1+ required for ARM64
VMware Fusion	✅*	✅	Apple Silicon supported; *AMD64 is local-build only — Vagrant Cloud ships ARM64 (CI runner limitation)

Quick Start

Installation

# 24.04 ext4 (default, stable, general purpose)
vagrant init dasomel/ubuntu-24.04-ext4
vagrant up --provider=vmware_desktop

# 24.04 xfs (better for K8s ephemeral storage quota, large files)
vagrant init dasomel/ubuntu-24.04-xfs
vagrant up --provider=vmware_desktop

# 26.04 (Resolute Raccoon, kernel Linux 7.0)
vagrant init dasomel/ubuntu-26.04-ext4
vagrant up --provider=vmware_desktop

Filesystem Comparison

	ext4	xfs
Best for	General purpose	K8s workloads, large files
K8s Quota	No native support	--local-storage-capacity-isolation
Online Shrink	Supported	Not supported
Box Size	~2.2GB	~3.4GB

Vagrantfile Example

Vagrant.configure("2") do |config|
  # 24.04: "dasomel/ubuntu-24.04-ext4" or "dasomel/ubuntu-24.04-xfs"
  # 26.04: "dasomel/ubuntu-26.04-ext4" or "dasomel/ubuntu-26.04-xfs"
  config.vm.box = "dasomel/ubuntu-24.04-ext4"

  config.vm.provider "virtualbox" do |vb|
    vb.memory = 4096
    vb.cpus = 2
  end

  config.vm.provider "vmware_desktop" do |v|
    v.vmx["memsize"] = "4096"
    v.vmx["numvcpus"] = "2"
  end

  config.vm.hostname = "k8s-node"
  config.vm.network "private_network", ip: "192.168.56.10"
end

What's Included

OS Optimizations

• Kernel Parameters: Network, memory, and filesystem tuning (vm.max_map_count=1048576)
• Resource Limits: File descriptors, processes, memory locks
• K8s Prerequisites: Swap disabled, required kernel modules (br_netfilter, overlay, iscsi_tcp), IP forwarding, persistent bpffs mount (/sys/fs/bpf for Cilium), CSI storage prerequisites (open-iscsi with iscsid enabled, cryptsetup, dmsetup, nfs-common for Longhorn V1)
• Security & Compliance: unattended-upgrades purged (kubelet Graceful Node Shutdown conflict), needrestart removed (Qualys LPE CVEs), auditd installed (disabled by default, CIS benchmark ready with bounded I/O settings)
• Time Synchronization: chrony replacing systemd-timesyncd (Ubuntu 25.10+/26.04 default, K8s/etcd recommended), Korean NTP servers configured via /etc/chrony/sources.d/kr-ntp.sources
• Disk I/O: Scheduler and read-ahead optimization
• Network: TCP buffers, conntrack, ring buffers, dhcp-identifier: mac netplan configuration (fixes 26.04 post-install IP change SSH timeout)

Pre-installed Tools

Category	Tools
K8s Ecosystem	jq, yq, bash-completion, nfs-common, open-iscsi, cryptsetup, dmsetup, apparmor-utils, sshpass
Security & Audit	auditd (disabled by default)
Monitoring	sysstat, iotop, iftop, nload, nethogs, dool
Network Diag	ipvsadm, ipset, conntrack, ethtool, tcpdump, nmap
Performance	linux-tools, bpfcc-tools, bpftrace

What's NOT Included

Users install these components based on their requirements:

• Container runtime (containerd, CRI-O)
• Kubernetes (kubeadm, kubelet, kubectl)
• CNI plugins (Flannel, Calico, Cilium)

K8s Installation (After Box Setup)

# 1. Install containerd
sudo apt-get update && sudo apt-get install -y containerd
sudo mkdir -p /etc/containerd
containerd config default | sudo tee /etc/containerd/config.toml
sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml
sudo systemctl restart containerd && sudo systemctl enable containerd

# 2. Install K8s (choose your version)
K8S_VERSION="v1.31"
curl -fsSL "https://pkgs.k8s.io/core:/stable:/${K8S_VERSION}/deb/Release.key" | \
  sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/${K8S_VERSION}/deb/ /" | \
  sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update && sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

# 3. Initialize cluster (master node)
sudo kubeadm init --pod-network-cidr=10.244.0.0/16

Verify Box Tuning

# Check tuning settings
vagrant ssh -c "cat /etc/vagrant-box/info.json"
vagrant ssh -c "/bin/bash /etc/vagrant-box/check-tuning.sh"

Documentation

• Box Usage Guide - Detailed usage instructions
• K8s Post-Install - containerd/kubelet tuning
• Packer Build Guide - Building boxes from source
• Vagrant Cloud Guide - Upload, manage, and delete boxes
• HCP Credentials Setup - Rotate HCP service principal keys
• Deploy Checklist - Pre-release verification
• Legal & Licensing - OSS licenses and compliance
• Changelog - Release notes and version history

Building from Source

cd packer

# Initialize Packer plugins
./build.sh init

# Build 24.04 (default)
./build.sh vmware-arm64
./build.sh vmware-arm64 --fs=xfs

# Build 26.04
./build.sh vmware-arm64 --version=26.04
./build.sh vmware-arm64 --version=26.04 --fs=xfs

# Build all boxes
./build.sh all                         # 24.04 ext4
./build.sh all --version=26.04         # 26.04 ext4

# Upload (root script)
UBUNTU_VERSION=26.04 ./upload-boxes.sh # 26.04 upload

CI: Use the ubuntu_version input in the GitHub Actions workflow_dispatch trigger to select 24.04 or 26.04.

Requirements

For Using the Box

• Vagrant 2.3+
• VirtualBox 7.1+ (for ARM64) or VMware Fusion

For Building from Source

• Packer 1.10+ (CI pinned to 1.15.4)
• VirtualBox 7.1+ / VMware Fusion
• 20GB+ disk space per box
• Build timeouts: ssh_timeout 1h (2h for vmware-arm64), CI job timeout 90m

License

This project is licensed under the MIT License - see the LICENSE file for details.

Third-Party Licenses

This box includes software from various open source projects. See NOTICE for details.

Component	License
Ubuntu 24.04 / 26.04	Various
Kubernetes	Apache 2.0
containerd	Apache 2.0

For AI-Assisted Development

This project includes comprehensive context files for AI coding assistants in the .agent/ directory:

• AGENT.md - Complete technical guide (Packer, K8s tuning, optimizations)
• SECURITY.md - Security guidelines and best practices
• skills/ - AI agent skills for automated reviews

While designed for tools like Claude Code, these files contain valuable technical documentation for all developers working with Packer, Kubernetes, or Ubuntu optimization.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Links

• Vagrant Cloud - 24.04 ext4
• Vagrant Cloud - 24.04 xfs
• Vagrant Cloud - 26.04 ext4
• Vagrant Cloud - 26.04 xfs
• GitHub Repository
• Issue Tracker