vm-bakery

Create a reusable Ubuntu golden image and spin up development VMs quickly with QEMU.

What it does

• Builds a pre-provisioned Ubuntu cloud golden.qcow2 image (packages + your SSH key).
• Lets you create ephemeral run overlays from that golden image and boot them with QEMU.
• Provides tiny helpers to start, stop, list and SSH into runs.

Must-knows

• The scripts use ./dev-vm under the repo as the workspace (images, run, artifacts, …).
• Default VM user: tester. Default SSH port: 2222. Default SSH key: ~/.ssh/id_ed25519 / .pub.
• Designed for Debian/Ubuntu hosts — the scripts will try to install missing packages (sudo required).
• KVM is used if available; if not, QEMU will still run (slower).
• Keep a usable SSH keypair locally — the golden image is provisioned with your public key.

Quickstart (the commands you actually need)

1. (From repo root) create the golden image (uses your ~/.ssh/id_ed25519.pub by default):

./make-golden-vm.sh

If you use a different public key or port:

./make-golden-vm.sh --ssh-key /path/to/key.pub --ssh-port 2223

2. Boot a run overlay (reuse latest run overlay by default):

./run-vm.sh

Create a fresh overlay and run it:

./run-vm.sh --new

3. SSH into the running VM:

ssh -i ~/.ssh/id_ed25519 -p 2222 tester@127.0.0.1

(Or use ./vmctl.sh ssh — see next section.)

Handy commands (vmctl)

./vmctl.sh wraps common tasks:

• ./vmctl.sh list — show run images, pids, and forwarded ports.
• ./vmctl.sh start [--new] [name] — start a run (delegates to run-vm.sh).
• ./vmctl.sh stop [name] — stop a run (by name or latest).
• ./vmctl.sh ssh [name] — SSH into a run (uses per-project known_hosts).
• ./vmctl.sh info [name] — show pidfile and port for a run.

Tips & troubleshooting

• If /dev/kvm is missing, the scripts will try to load kernel modules; if it still isn't available your VM runs without KVM (slower).
• If SSH doesn't come up during golden provisioning, check QEMU console or the printed guest-selfcheck output.
• Golden image path: ./dev-vm/images/golden.qcow2. Run overlays live under ./dev-vm/run/.
• To create a manual overlay:

qemu-img create -f qcow2 -b dev-vm/images/golden.qcow2 dev-vm/run/run-YYYYmmdd-HHMMSS.qcow2

Why this is useful

• Build once, branch many runs: keep a single pre-provisioned image and spawn disposable VMs quickly for testing, debugging, or development.