Add Ubuntu 26.04 virtual machine

Add run-ubuntu2604.py with its QEMU config files and NoCloud seed. The
launcher follows the Debian 13 one, with UBUNTU_VM_ settings and SSH
forwarded to host port 2225. The seed injects the current user's SSH public
key, uses the USTC mirror (ubuntu-ports on arm64) and installs the GNOME
desktop on first boot. Update vm-images for the ubuntu2604 image target.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Kwxp2XWvKnuEBifnCbhyX5

README.md

@@ -6,6 +6,7 @@ Start the required operating system with its distribution-specific launcher:
 ./run-debian13.py
 ./run-almalinux10.py
 ./run-fedora44.py
+./run-ubuntu2604.py
 ./run-windows11.py
 ```
 
@@ -46,8 +47,8 @@ corresponding `*_STATE_DIR` environment variable:
 
 With `--download-only`, a launcher only downloads the media it would fetch
 automatically and then exits without creating a VM disk or starting QEMU: the
-base image for Debian, AlmaLinux and Fedora, and the VirtIO tools ISO for
+base image for Debian, AlmaLinux, Fedora and Ubuntu, and the VirtIO tools ISO
-Windows 11 (whose installation ISO and base QCOW2 are supplied manually):
+for Windows 11 (whose installation ISO and base QCOW2 are supplied manually):
 
 ```bash
 ./run-fedora44.py --download-only
@@ -126,6 +127,35 @@ architecture-specific devices in `qemu/fedora44-amd64.ini` and
 `qemu/fedora44-arm64.ini`. Other Fedora settings use the `FEDORA_VM_` prefix.
 Run `./run-fedora44.py --help` for the complete list of overrides.
 
+## Ubuntu 26.04
+
+Start an Ubuntu 26.04 LTS (Resolute Raccoon) cloud image VM with:
+
+```bash
+./run-ubuntu2604.py
+```
+
+The launcher downloads the `ubuntu2604` image through the shared helper when
+it is missing, creates `.vm/ubuntu2604/disk.qcow2`, and builds its NoCloud seed
+from `seediso/ubuntu2604/`. Like the Debian seed, it injects the current user's
+SSH public key and points APT at the USTC mirror (`ubuntu-ports` on arm64).
+SSH is forwarded to host port `2225` by default:
+
+```bash
+ssh -p 2225 guofang@localhost
+```
+
+On the first boot, cloud-init installs `ubuntu-desktop-minimal` (GNOME) and
+`ibus-table-wubi`, makes the graphical target the default and reboots the
+guest. Keep the VM running until this initial installation and reboot have
+completed.
+
+The VM hardware (8G memory, 8 CPUs, drives, SSH port `2225`) is defined in
+`qemu/ubuntu2604.ini`, with the machine type and architecture-specific devices
+in `qemu/ubuntu2604-amd64.ini` and `qemu/ubuntu2604-arm64.ini`. Other Ubuntu
+settings use the `UBUNTU_VM_` prefix. Run `./run-ubuntu2604.py --help` for the
+complete list of overrides.
+
 ## Windows 11 23H2
 
 On first boot, the Windows 11 launcher creates a writable system-disk overlay

qemu/ubuntu2604-amd64.ini

@@ -0,0 +1,4 @@
+# amd64 part of the Ubuntu 26.04 QEMU configuration; read after ubuntu2604.ini.
+
+[machine]
+  type = "q35"

qemu/ubuntu2604-arm64.ini

@@ -0,0 +1,17 @@
+# arm64 part of the Ubuntu 26.04 QEMU configuration; read after ubuntu2604.ini.
+
+[machine]
+  type = "virt"
+
+# Unlike q35, the "virt" machine has no default GPU or USB input devices.
+[device "gpu0"]
+  driver = "virtio-gpu-pci"
+
+[device "usb0"]
+  driver = "qemu-xhci"
+
+[device "kbd0"]
+  driver = "usb-kbd"
+
+[device "tablet0"]
+  driver = "usb-tablet"

qemu/ubuntu2604.ini

@@ -0,0 +1,69 @@
+# QEMU configuration for the Ubuntu 26.04 virtual machine, shared by all
+# architectures. The machine type and architecture-specific devices are in
+# ubuntu2604-<arch>.ini, which QEMU reads after this file.
+#
+# run-ubuntu2604.py fills in the file path placeholders below, writes the result
+# to <state dir>/qemu.ini and passes it to QEMU with -readconfig. Options that
+# have no -readconfig equivalent (-cpu, -display, daemon mode) are still added
+# by the launcher.
+
+[name]
+  guest = "ubuntu2604"
+
+# Accelerators are tried in order: KVM on Linux, HVF on macOS, else emulation.
+[accel]
+  accel = "kvm"
+
+[accel]
+  accel = "hvf"
+
+[accel]
+  accel = "tcg"
+
+[memory]
+  size = "8G"
+
+[smp-opts]
+  cpus = "8"
+
+# UEFI firmware: read-only code and the per-VM variable store.
+[drive "pflash0"]
+  if = "pflash"
+  format = "raw"
+  readonly = "on"
+  file = "${uefi_code}"
+
+[drive "pflash1"]
+  if = "pflash"
+  format = "raw"
+  file = "${uefi_vars}"
+
+# Writable qcow2 overlay on top of the shared base image.
+[drive "disk0"]
+  if = "none"
+  format = "qcow2"
+  file = "${disk_image}"
+
+[device "disk0-dev"]
+  driver = "virtio-blk-pci"
+  drive = "disk0"
+
+# cloud-init seed ISO.
+[drive "seed0"]
+  if = "none"
+  format = "raw"
+  readonly = "on"
+  file = "${seed_image}"
+
+[device "seed0-dev"]
+  driver = "virtio-blk-pci"
+  drive = "seed0"
+
+# User-mode networking with guest SSH forwarded to the host.
+[netdev "net0"]
+  type = "user"
+  hostfwd = "tcp::2225-:22"
+
+[device "nic0"]
+  driver = "virtio-net-pci"
+  netdev = "net0"

run-ubuntu2604.py

@@ -0,0 +1,296 @@
+#!/usr/bin/env python3
+"""Start the Ubuntu 26.04 virtual machine."""
+
+import os
+import platform
+import re
+import shutil
+import string
+import subprocess
+import sys
+from pathlib import Path
+
+script_dir = Path(__file__).resolve().parent
+env = os.environ.get
+
+
+def die(message, code=1):
+    print(f"Error: {message}", file=sys.stderr)
+    sys.exit(code)
+
+
+def run(command):
+    """Run a command, exiting with its status on failure (like `set -e`)."""
+    result = subprocess.run(command)
+    if result.returncode != 0:
+        sys.exit(result.returncode)
+
+
+def is_executable(path):
+    return path.is_file() and os.access(path, os.X_OK)
+
+
+if env("VM_IMAGE_HELPER"):
+    image_downloader = Path(env("VM_IMAGE_HELPER"))
+elif is_executable(script_dir / "vm-images" / "download-images.sh"):
+    image_downloader = script_dir / "vm-images" / "download-images.sh"
+else:
+    image_downloader = script_dir / ".." / "vm-images" / "download-images.sh"
+
+uses_shared_base_image = False
+if env("UBUNTU_VM_BASE_IMAGE"):
+    base_image = Path(env("UBUNTU_VM_BASE_IMAGE"))
+else:
+    if not is_executable(image_downloader):
+        die(f"shared image helper is unavailable: {image_downloader}")
+    result = subprocess.run(
+        [str(image_downloader), "--print-path", "ubuntu2604"],
+        stdout=subprocess.PIPE,
+        text=True,
+    )
+    if result.returncode != 0:
+        sys.exit(result.returncode)
+    base_image = Path(result.stdout.rstrip("\n"))
+    uses_shared_base_image = True
+
+state_dir = Path(env("UBUNTU_VM_STATE_DIR") or script_dir / ".vm" / "ubuntu2604")
+disk_size = env("UBUNTU_VM_DISK_SIZE") or "20G"
+
+
+def normalize_arch(arch):
+    if arch in ("arm64", "aarch64"):
+        return "arm64"
+    if arch in ("x86_64", "amd64"):
+        return "amd64"
+    die(f"unsupported architecture: {arch}")
+
+
+native_arch = normalize_arch(platform.machine())
+host_arch = normalize_arch(env("VM_IMAGE_ARCH") or native_arch)
+qemu_binary = "qemu-system-aarch64" if host_arch == "arm64" else "qemu-system-x86_64"
+qemu_config_template = Path(
+    env("UBUNTU_VM_QEMU_CONFIG") or script_dir / "qemu" / "ubuntu2604.ini")
+qemu_arch_config = script_dir / "qemu" / f"ubuntu2604-{host_arch}.ini"
+
+
+def pick_firmware(override, *candidates):
+    if override:
+        return Path(override)
+    for candidate in candidates:
+        if Path(candidate).is_file():
+            return Path(candidate)
+    return Path(candidates[0])
+
+
+if host_arch == "arm64":
+    uefi_code = pick_firmware(
+        env("UBUNTU_VM_UEFI_CODE"),
+        "/usr/share/AAVMF/AAVMF_CODE.fd",
+        "/usr/share/edk2/aarch64/QEMU_EFI.fd",
+        "/opt/homebrew/share/qemu/edk2-aarch64-code.fd",
+        "/usr/local/share/qemu/edk2-aarch64-code.fd",
+    )
+    uefi_vars_template = pick_firmware(
+        env("UBUNTU_VM_UEFI_VARS"),
+        "/usr/share/AAVMF/AAVMF_VARS.fd",
+        "/usr/share/edk2/aarch64/vars-template-pflash.raw",
+        "/opt/homebrew/share/qemu/edk2-arm-vars.fd",
+        "/usr/local/share/qemu/edk2-arm-vars.fd",
+    )
+else:
+    uefi_code = pick_firmware(
+        env("UBUNTU_VM_UEFI_CODE"),
+        "/usr/share/OVMF/OVMF_CODE_4M.fd",
+        "/usr/share/edk2/ovmf/OVMF_CODE.fd",
+        "/opt/homebrew/share/qemu/edk2-x86_64-code.fd",
+        "/usr/local/share/qemu/edk2-x86_64-code.fd",
+    )
+    uefi_vars_template = pick_firmware(
+        env("UBUNTU_VM_UEFI_VARS"),
+        "/usr/share/OVMF/OVMF_VARS_4M.fd",
+        "/usr/share/edk2/ovmf/OVMF_VARS.fd",
+        "/opt/homebrew/share/qemu/edk2-i386-vars.fd",
+        "/usr/local/share/qemu/edk2-i386-vars.fd",
+    )
+daemonize = False
+download_only = False
+extra_args = []
+
+
+def usage(stream=sys.stdout):
+    stream.write(f"""\
+Usage: {Path(sys.argv[0]).name} [--daemon] [--download-only] [--state-dir DIR] [-- QEMU_ARGUMENT ...]
+
+Start an Ubuntu 26.04 LTS cloud image virtual machine. A writable overlay is
+created in the state directory (default: .vm/ubuntu2604/), so the downloaded
+base image is never modified. The VM hardware (memory, CPUs, SSH port forward,
+...) is defined in qemu/ubuntu2604.ini, which is rendered to qemu.ini in the
+state directory and loaded with QEMU's -readconfig, followed by
+qemu/ubuntu2604-<arch>.ini. Later QEMU arguments override them, e.g.
+`-- -m 4G -smp 4`.
+
+Options:
+  --daemon         Run in the background while keeping the graphical window
+  --download-only  Download the base image if it is missing, then exit
+  --state-dir DIR  Directory for the VM disk, seed ISO and runtime files
+                   (default: .vm/ubuntu2604; overrides UBUNTU_VM_STATE_DIR)
+  -h, --help       Show this help
+
+Environment variables:
+  UBUNTU_VM_BASE_IMAGE     Base qcow2 image path (default: resolved by shared image helper)
+  UBUNTU_VM_SEED_IMAGE     cloud-init seed ISO path (default: alongside the VM disk)
+  UBUNTU_VM_STATE_DIR      Runtime state directory (default: .vm/ubuntu2604)
+  UBUNTU_VM_DISK_IMAGE     Writable overlay path
+  UBUNTU_VM_DISK_SIZE      New overlay virtual capacity (default: 20G)
+  VM_IMAGE_ARCH            Guest/host architecture: arm64 or amd64 (default: auto-detected from the host)
+  UBUNTU_VM_UEFI_CODE      UEFI read-only firmware path (auto-detected for the selected architecture)
+  UBUNTU_VM_UEFI_VARS      UEFI variable-store template path (auto-detected for the selected architecture)
+  UBUNTU_VM_DISPLAY        QEMU display backend (default: cocoa on macOS, gtk elsewhere)
+  UBUNTU_VM_QEMU_CONFIG    QEMU config template rendered into the state directory and
+                           passed to -readconfig (default: qemu/ubuntu2604.ini)
+""")
+
+
+args = sys.argv[1:]
+while args:
+    arg = args.pop(0)
+    if arg == "--daemon":
+        daemonize = True
+    elif arg == "--download-only":
+        download_only = True
+    elif arg == "--state-dir":
+        if not args:
+            die(f"{arg} requires a directory argument.", 2)
+        state_dir = Path(args.pop(0))
+    elif arg.startswith("--state-dir="):
+        state_dir = Path(arg.split("=", 1)[1])
+    elif arg in ("-h", "--help"):
+        usage()
+        sys.exit(0)
+    elif arg == "--":
+        extra_args.extend(args)
+        break
+    else:
+        print(f"Error: unknown option: {arg}", file=sys.stderr)
+        usage(sys.stderr)
+        sys.exit(2)
+
+disk_image = Path(env("UBUNTU_VM_DISK_IMAGE") or state_dir / "disk.qcow2")
+seed_image = Path(env("UBUNTU_VM_SEED_IMAGE") or disk_image.parent / "seed.iso")
+uefi_vars = state_dir / "OVMF_VARS_4M.fd"
+pid_file = state_dir / "qemu.pid"
+log_file = state_dir / "console.log"
+qemu_config = state_dir / "qemu.ini"
+
+if not download_only:
+    for command_name in (qemu_binary, "qemu-img"):
+        if shutil.which(command_name) is None:
+            die(f"{command_name} is not installed.")
+
+if not base_image.is_file():
+    if uses_shared_base_image:
+        run([str(image_downloader), "ubuntu2604"])
+    else:
+        die(f"Ubuntu base image was not found: {base_image}")
+if not base_image.is_file():
+    die(f"downloader did not create: {base_image}")
+if download_only:
+    print(f"Base image is ready: {base_image}")
+    sys.exit(0)
+for firmware_file in (uefi_code, uefi_vars_template):
+    if not firmware_file.is_file():
+        die(f"required UEFI firmware was not found: {firmware_file}")
+
+if not seed_image.is_file():
+    seed_builder = script_dir / "seediso" / "ubuntu2604" / "build-seed.sh"
+    if not is_executable(seed_builder):
+        die(f"seed image is missing and builder is unavailable: {seed_builder}")
+    print(f"Seed image not found; building {seed_image}...", flush=True)
+    run([str(seed_builder), str(seed_image)])
+
+state_dir.mkdir(parents=True, exist_ok=True)
+
+# QEMU requires the code and vars pflash images to be exactly the same size.
+# Homebrew's edk2 firmware ships code/vars pairs at mismatched sizes (true for
+# both the aarch64 and x86_64 pairs), so pad per-VM copies of whichever one is
+# smaller up to match the other.
+uefi_code_flash = state_dir / "OVMF_CODE_4M.fd"
+if not uefi_code_flash.is_file() or not uefi_vars.is_file():
+    flash_size = max(uefi_code.stat().st_size, uefi_vars_template.stat().st_size)
+    for source, target in ((uefi_code, uefi_code_flash), (uefi_vars_template, uefi_vars)):
+        if not target.is_file():
+            shutil.copyfile(source, target)
+            os.truncate(target, flash_size)
+
+if pid_file.is_file():
+    old_pid = pid_file.read_text().strip()
+    if old_pid.isdigit():
+        try:
+            os.kill(int(old_pid), 0)
+        except OSError:
+            pass
+        else:
+            die(f"the Ubuntu virtual machine is already running (PID {old_pid}).")
+    pid_file.unlink(missing_ok=True)
+
+if not disk_image.is_file():
+    run(["qemu-img", "create", "-q", "-f", "qcow2", "-F", "qcow2",
+         "-b", str(base_image), str(disk_image), disk_size])
+    print(f"Created writable disk overlay: {disk_image}")
+
+is_macos = platform.system() == "Darwin"
+display_backend = env("UBUNTU_VM_DISPLAY") or ("cocoa" if is_macos else "gtk")
+
+# Most of the VM definition lives in the QEMU config template; fill in the
+# file paths and hand the rendered file to QEMU with -readconfig.
+config_values = {
+    "uefi_code": uefi_code_flash,
+    "uefi_vars": uefi_vars,
+    "disk_image": disk_image,
+    "seed_image": seed_image,
+}
+for key, value in config_values.items():
+    # QEMU's config file parser has no escape syntax for quoted values.
+    if any(char in str(value) for char in '"\n'):
+        die(f"{key} must not contain double quotes or newlines: {value}")
+for config_file in (qemu_config_template, qemu_arch_config):
+    if not config_file.is_file():
+        die(f"QEMU config file was not found: {config_file}")
+try:
+    qemu_config_text = string.Template(qemu_config_template.read_text()).substitute(
+        {key: str(value) for key, value in config_values.items()})
+except (KeyError, ValueError) as error:
+    die(f"invalid placeholder in {qemu_config_template}: {error}")
+qemu_config.write_text(qemu_config_text)
+
+qemu_args = [
+    "-readconfig", str(qemu_config),
+    "-readconfig", str(qemu_arch_config),
+    # "max" is the host CPU under KVM/HVF and the fullest model under TCG.
+    "-cpu", "max",
+    # The config file's [netdev] does not stop QEMU from adding its default
+    # NIC, a second user network without the SSH port forward.
+    "-nic", "none",
+    "-display", display_backend,
+]
+
+print(f"Starting Ubuntu 26.04 ({host_arch}) from {qemu_config_template} "
+      f"and {qemu_arch_config}.", flush=True)
+# The SSH port forward lives in the config file, e.g. hostfwd = "tcp::2225-:22".
+ssh_forward = re.search(r'hostfwd\s*=\s*"tcp:[^:"]*:(\d+)-[^:"]*:22"', qemu_config_text)
+if ssh_forward:
+    print(f"SSH is forwarded to localhost:{ssh_forward.group(1)}: "
+          f"ssh -p {ssh_forward.group(1)} guofang@localhost", flush=True)
+
+if daemonize:
+    log_file.write_text("")
+    qemu_args += [
+        "-serial", f"file:{log_file}",
+        "-monitor", "none",
+        "-daemonize",
+        "-pidfile", str(pid_file),
+    ]
+    run([qemu_binary, *qemu_args, *extra_args])
+    print(f"VM started (PID {pid_file.read_text().strip()}); console log: {log_file}")
+else:
+    os.execvp(qemu_binary, [qemu_binary, *qemu_args, *extra_args])

seediso/README.md

@@ -7,7 +7,8 @@ Each operating system has an independent NoCloud configuration and generated
 seediso/
 ├── debian13/
 ├── almalinux10/
-└── fedora44/
+├── fedora44/
+└── ubuntu2604/
 ```
 
 Keeping per-OS metadata separate allows each VM to use a distinct hostname and

seediso/ubuntu2604/.gitignore

@@ -0,0 +1,2 @@
+seed.iso
+*.iso

seediso/ubuntu2604/README.md

@@ -0,0 +1,21 @@
+# Ubuntu 26.04 seed.iso
+
+This directory contains the cloud-init NoCloud configuration used by
+`run-ubuntu2604.py`.
+
+1. Edit `user-data`, `meta-data`, and (if needed) `network-config`.
+2. Build the image:
+
+   ```bash
+   ./seediso/ubuntu2604/build-seed.sh
+   ```
+
+   To choose another output path:
+
+   ```bash
+   ./seediso/ubuntu2604/build-seed.sh /path/to/seed.iso
+   ```
+
+The script uses `cloud-localds` when available, then falls back to `xorriso`,
+`genisoimage`, or `mkisofs`. Attach the resulting ISO as a CD-ROM when booting
+a cloud-init-enabled virtual machine.

seediso/ubuntu2604/build-seed.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+script_dir="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+output="${1:-${script_dir}/seed.iso}"
+files=(user-data meta-data)
+
+# Public key injected into user-data: $SSH_PUBKEY_FILE, else the first
+# ~/.ssh/id_*.pub, else the first key offered by ssh-agent.
+pubkey=""
+if [[ -n "${SSH_PUBKEY_FILE:-}" ]]; then
+  pubkey="$(head -n1 -- "${SSH_PUBKEY_FILE}")"
+else
+  for f in "${HOME}"/.ssh/id_ed25519.pub "${HOME}"/.ssh/id_*.pub; do
+    if [[ -f "$f" ]]; then pubkey="$(head -n1 -- "$f")"; break; fi
+  done
+  if [[ -z "$pubkey" ]] && command -v ssh-add >/dev/null 2>&1; then
+    pubkey="$(ssh-add -L 2>/dev/null | head -n1 || true)"
+  fi
+fi
+if [[ "$pubkey" != ssh-* && "$pubkey" != ecdsa-* && "$pubkey" != sk-* ]]; then
+  printf 'Error: no SSH public key found; set SSH_PUBKEY_FILE.\n' >&2
+  exit 1
+fi
+
+work="$(mktemp -d)"
+trap 'rm -rf -- "${work}"' EXIT
+template="$(<"${script_dir}/user-data")"
+printf '%s\n' "${template//@SSH_PUBKEY@/${pubkey}}" > "${work}/user-data"
+cp -- "${script_dir}/meta-data" "${work}/meta-data"
+if [[ -f "${script_dir}/network-config" ]]; then
+  cp -- "${script_dir}/network-config" "${work}/network-config"
+fi
+
+mkdir -p "$(dirname -- "$output")"
+
+if [[ -f "${script_dir}/network-config" ]]; then
+  files+=(network-config)
+fi
+
+if command -v cloud-localds >/dev/null 2>&1; then
+  args=()
+  if [[ -f "${script_dir}/network-config" ]]; then
+    args+=(--network-config="${work}/network-config")
+  fi
+  cloud-localds "${args[@]}" "${output}" \
+    "${work}/user-data" "${work}/meta-data"
+elif command -v xorriso >/dev/null 2>&1; then
+  xorriso -as mkisofs -quiet -volid cidata -joliet -rock \
+    -output "${output}" "${files[@]/#/${work}/}"
+elif command -v genisoimage >/dev/null 2>&1; then
+  genisoimage -quiet -output "${output}" -volid cidata -joliet -rock \
+    "${files[@]/#/${work}/}"
+elif command -v mkisofs >/dev/null 2>&1; then
+  mkisofs -quiet -output "${output}" -volid cidata -joliet -rock \
+    "${files[@]/#/${work}/}"
+else
+  printf 'Error: install cloud-image-utils, xorriso, genisoimage, or mkisofs.\n' >&2
+  exit 1
+fi
+
+printf 'Created %s\n' "${output}"

seediso/ubuntu2604/meta-data

@@ -0,0 +1,2 @@
+instance-id: ubuntu2604-host-001
+local-hostname: ubuntu2604-host

seediso/ubuntu2604/network-config

@@ -0,0 +1,10 @@
+version: 2
+ethernets:
+  all-en:
+    match:
+      name: "en*"
+    dhcp4: true
+  all-eth:
+    match:
+      name: "eth*"
+    dhcp4: true

seediso/ubuntu2604/user-data

@@ -0,0 +1,46 @@
+#cloud-config
+preserve_hostname: false
+manage_etc_hosts: true
+ssh_pwauth: true
+
+users:
+  - name: guofang
+    gecos: Guofang
+    groups: [sudo]
+    shell: /bin/bash
+    sudo: "ALL=(ALL) NOPASSWD: ALL"
+    lock_passwd: false
+    ssh_authorized_keys:
+      - @SSH_PUBKEY@
+    hashed_passwd: $6$0NtCERV3eO12t9oJ$nlFE2sSc66nFfuD5X0xMnOla1cuzOnHfeGNRY5X7dCDHg.WzWVmuRe7M17Puj44.eCWLnJAWt4WNjd9vP9X0D0
+
+chpasswd:
+  expire: false
+
+# amd64 packages are in the ubuntu archive, arm64 packages in ubuntu-ports.
+apt:
+  primary:
+    - arches: [amd64, i386]
+      uri: "https://mirrors.ustc.edu.cn/ubuntu"
+    - arches: [default]
+      uri: "https://mirrors.ustc.edu.cn/ubuntu-ports"
+  security:
+    - arches: [amd64, i386]
+      uri: "https://mirrors.ustc.edu.cn/ubuntu"
+    - arches: [default]
+      uri: "https://mirrors.ustc.edu.cn/ubuntu-ports"
+
+package_update: true
+
+packages:
+  - ubuntu-desktop-minimal
+  - ibus-table-wubi
+
+runcmd:
+  - systemctl set-default graphical.target
+
+power_state:
+  delay: now
+  mode: reboot
+  message: "GNOME installation completed; rebooting into graphical mode."
+  condition: true