debsb 0.1.2

Debian Sid Sandbox — instant QEMU/KVM VM from cloud images

debsb

Debian Sid sandbox in one command. Downloads a Debian cloud image, boots it in QEMU/KVM, and gives you an isolated VM with auto-login, SSH, and shared filesystem. No kernel building, no complex setup.

Install

pip install debsb

Dependencies

• qemu-system-x86_64 (with KVM support)
• cloud-image-utils (cloud-localds)
• whois (mkpasswd)
• wget
• ssh

On Debian/Ubuntu:

sudo apt install qemu-system-x86 cloud-image-utils whois wget openssh-client

Usage

Build the sandbox (one-time)

debsb build --size 20G

This downloads the Debian Sid cloud image, configures SSH keys and auto-login, and runs first boot. All artifacts are stored in ~/.debsb/.

Use --reset to skip the prompt and rebuild from scratch:

debsb build --size 20G --reset

Run the sandbox

# Serial console (auto-login as debian, Ctrl-A X to quit)
debsb run

# SSH session (as debian)
debsb run --ssh

# SSH as root
debsb run --ssh --root

# Run a command and auto-shutdown (requires --ssh)
debsb run --ssh --root --exec "apt update && apt upgrade -y"

# Graphical QEMU window
debsb run --graphics

# With sound
debsb run --sound

# Extra QEMU options
debsb run --qemu-opts='-m 8192'

Execute a command

--exec runs a command via SSH and shuts down automatically. Requires --ssh:

debsb run --ssh --exec "uname -a"
debsb run --ssh --root --exec "ls -ahl .debsb"
debsb run --ssh --exec "./my-script.sh"

This is useful for CI/automation. The exit code of the command is propagated.

Verbose mode

Show kernel boot messages:

debsb run --verbose

Shared filesystem

Your host ~/.debsb/ directory is mounted inside the VM at:

• /root/.debsb (symlink to /mnt/debsb)
• /home/debian/.debsb (symlink to /mnt/debsb)

This is automatic — no manual mounting needed.

How it works

1. Downloads debian-sid-generic-amd64-daily.qcow2 from cloud.debian.org
2. Creates a cloud-init ISO with SSH keys, user config, and auto-login
3. Boots the VM with QEMU/KVM and waits for cloud-init to finish
4. On subsequent debsb run, boots the prepared image directly

Accounts

User	Access
debian	Serial auto-login, SSH with key, sudo NOPASSWD
root	SSH with key (--root flag)

SSH key: ~/.debsb/id_ed25519 (auto-generated on first build)

License

GPL-2.0-only