Setup Context Skill

Configure the .env file for managing VMs on a hypervisor.

Instructions

Step 1: Ask for Backend Type

Use AskUserQuestion to ask which backend:

• libvirt - Local QEMU/KVM via libvirt
• proxmox - Remote Proxmox VE server via SSH (KVM VMs)
• proxmox-lxc - Remote Proxmox VE server via SSH (LXC containers; mutable-only, supports host ZFS bind mounts and the nas profile)

Step 2: Gather Backend-Specific Settings

For libvirt backend:

Most users can accept defaults. Only ask about non-default settings if user indicates special requirements (like running from a container).

Create .env with just:

BACKEND=libvirt

For proxmox backend:

Ask the user (as plain text prompts, not multiple choice):

• PVE_HOST (required) - SSH config host name (e.g., pve) or hostname/IP
• PVE_STORAGE - Storage for VM disks (default: local)
• PVE_BRIDGE - Network bridge (default: vmbr0)

Explain that they should configure their SSH connection in ~/.ssh/config:

Host pve
    HostName 192.168.1.100
    User root
    Port 22

And use ssh-agent for key authentication:

eval $(ssh-agent)
ssh-add ~/.ssh/id_ed25519

For proxmox-lxc backend:

Same SSH setup as proxmox. Ask the user (plain text prompts):

• PVE_HOST (required) - SSH config host name (e.g., pve) or hostname/IP
• PVE_STORAGE - CT-capable rootfs storage (a zfspool or dir storage, e.g. local-zfs or a pool name like rust; NOT a bare ZFS pool path). Check with ssh <host> pvesm status.
• PVE_BRIDGE - Network bridge (default: vmbr0)

Notes specific to this backend:

• LXC is mutable-only (read-write rootfs; nixos-rebuild runs inside). There is no immutable/semi-mutable mode.
• The nas profile (NFS + Samba) is LXC-only and runs the container privileged with an apparmor-unconfined override (for kernel NFS).
• Host ZFS datasets are bind-mounted into the container (<dataset>:<container-path>, e.g. rust/nas:/srv/nas); a bare dataset name is created on the host if missing. Configure these in the create wizard.

Example .env:

BACKEND=proxmox-lxc
PVE_HOST=pve
PVE_STORAGE=local-zfs
PVE_BRIDGE=vmbr0
PVE_BACKUP_STORAGE=local

Step 3: Create the .env file

Create/overwrite the .env file at the project root.

Example .env for libvirt:

BACKEND=libvirt

Example .env for proxmox:

BACKEND=proxmox
PVE_HOST=pve
PVE_STORAGE=local-lvm
PVE_BRIDGE=vmbr0
PVE_BACKUP_STORAGE=local

Step 4: Test Connection

After creating the .env file, run the connection test:

just test-connection

Important: Warn the user that they may need to authenticate multiple times during the test (SSH key passphrase prompts if not using ssh-agent, or host key verification).

If the test passes, tell the user the setup is complete and they can now use just commands.

Variable Reference

Libvirt Variables

Variable	Default	Description
BACKEND	libvirt	Set to libvirt
LIBVIRT_URI	qemu:///system	Libvirt connection URI
HOST_CMD	(empty)	Prefix for host commands (e.g., host-spawn for distrobox)

Proxmox Variables

Variable	Default	Description
BACKEND	-	Set to proxmox
PVE_HOST	(required)	SSH config host name (or hostname/IP)
PVE_NODE	$PVE_HOST	Proxmox node name (for clusters)
PVE_STORAGE	local	Proxmox storage for VM disks
PVE_BRIDGE	vmbr0	Network bridge name
PVE_DISK_FORMAT	qcow2	Disk format (qcow2, raw, vmdk)
PVE_BACKUP_STORAGE	local	Proxmox storage for backups

Proxmox-LXC Variables

Variable	Default	Description
BACKEND	-	Set to proxmox-lxc
PVE_HOST	(required)	SSH config host name (or hostname/IP)
PVE_NODE	$PVE_HOST	Proxmox node name (for clusters)
PVE_STORAGE	local	CT-capable rootfs storage (zfspool/dir; NOT a bare pool path)
PVE_BRIDGE	vmbr0	Network bridge name
PVE_BACKUP_STORAGE	local	Proxmox storage for backups
PVE_TEMPLATE_DIR	/var/lib/vz/template/cache	Where the LXC template tarball is staged
LXC_FEATURES	nesting=1	pct create --features value