hamlab/VIRTUALIZATION.md

# Virtualization tab — plan (2026-10-09, revised the same day; not started)

A tab for creating, watching, consoling into and deleting **LXC containers and KVM virtual
machines**, the way Proxmox does with `pct` and `qm` — **per machine, like every other
page.** This is the scoping PLAN.md asked for. Nothing here is built. Live state of the
hosts stays in `hamlet/docs/hosts.md`.

## The governing rule: capability, not policy

Stated by Mitchell 2026-10-09, after the first draft of this plan excluded hosts on the
strength of the homelab's deployment rules:

> Anything that's done when a different machine is selected SHOULD GO ON THAT machine. I
> want the option to do it anywhere I want, unless the hardware / software literally
> doesn't support it. Ham Lab needs to be built in a general-purpose way that can run on
> any Linux system. If certain parts / libraries aren't available on that machine, those
> tabs should just report that.

So:

- **Every action lands on the machine in the switcher.** There is no "VM host", no default
  machine, no cross-machine placement. `grid` is where he will most likely click first;
  the tab does not know or care.
- **The tab is gated by what the machine can do, detected live** — never by a rule about
  what *should* run there. The `hamlet/CLAUDE.md` do-not-break rules (Mac mini for
  single-core workloads, `hamtv` not spare hardware) bind the *agent's* unasked
  deployments. They are not feature gates for the product, and the first draft was wrong
  to treat them as such.
- **Ham Lab owns its data, and its data lives in its own folder.** Everything this tab
  manages — instance storage, ISOs, image tarballs, exports — sits under Ham Lab's data
  directory on *that* machine (`config.DataDir()`, `~/apps/hamlab` on `core`, `grid` and
  the Mac), in one `virt/` tree. Never a path elsewhere on the machine, however convenient
  the existing folder. Stated 2026-10-09 after the first Library draft pointed the ISO shelf
  at `/tank/software/isos/`: *"ALL data needs to be under a HamLab folder, because it
  manages its own data."* This is the rule that moved `core`'s compose files under
  `apps/hamlab/stacks/` on 2026-10-05; `grid`'s and the Mac's stacks, still at
  `~/stacks/<machine>/`, are the outstanding exception and are not touched by this plan.
  The engine's own runtime state (`/var/lib/incus`, like `/var/lib/docker`) is the engine's,
  not Ham Lab's data: Ham Lab keeps what it would need to rebuild it.
- **Ham Lab installs or reports.** It detects what is missing, offers to install it where it
  knows how, and where it cannot or the hardware cannot do the job, says so in one sentence
  and offers what *does* work (containers without KVM, for instance).

## Decision: Incus 6.0 LTS as the engine

| Option | Verdict |
|---|---|
| **Incus** (LXD fork, linuxcontainers.org) | **Chosen.** One daemon, one CLI and one JSON API for both containers and VMs. Packaged by Debian 13 (`incus` 6.0.4 LTS — `apt install incus` pulls `qemu-system-x86`, `swtpm`, `virtiofsd`, `incus-agent`, so VMs work out of the box), Fedora (6.23), Arch, Alpine, Ubuntu (Zabbly repo); not by OpenWrt. Storage drivers for ZFS, btrfs, LVM and plain directories, so it fits a machine with or without ZFS. Built-in image server (`images:debian/13`, `images:ubuntu/24.04`, Alpine, Fedora, Arch… as container *or* VM, per architecture), snapshot schedules with expiry, `incus export` backups, per-instance CPU/memory limits, cloud-init, text and VGA console over websocket. Everything is reachable as `incus … --format json` or `incus query`, which is exactly how Ham Lab already drives Docker: `exec.Command`, no new Go dependency, no cgo. |
| libvirt/KVM + `virsh`, plus LXC separately | Two daemons, two models, XML. libvirt's official Go binding needs cgo, which the static binary rules out (the pure-Go `go-libvirt` exists but then containers are a second project). Rejected. |
| Proxmox | An OS, not a library. Rejected. |

## What each machine can do today

Probed 2026-10-09 (`/dev/kvm`, cpu flags, kvm modules, RAM, disk, package availability).
These are **facts the tab will detect at runtime**, not a list of where instances are
allowed. The last column is what the tab would show the day it ships.

| Machine | Arch | KVM | RAM (free) | Incus from the package manager | Pool driver available | Tab state on first open |
|---|---|---|---|---|---|---|
| `grid` | x86-64 | yes — VT-x, `kvm_intel` loaded, nested on | 62 GiB (~25; ARC holds 23 of the rest, max 40) | apt: `incus` 6.0.4 | **zfs** (2.3.9, `tank`) | **Install** — containers and VMs |
| `core` | x86-64 | yes — N100, `kvm_intel` loaded | 7.5 GiB (~4) | apt: `incus` 6.0.4 | btrfs or dir (ZFS was purged 2026-09-23) | **Install** — containers and VMs; the create form shows free memory so a VM's size is an informed choice |
| Mac mini | aarch64 | yes — Asahi KVM, 16K pages | 15 GiB (~8) | dnf: `incus` 6.23, `qemu-system-aarch64-core`, `edk2-aarch64` | btrfs or dir | **Install** — containers and VMs, **arm64 images only** (the picker filters by host arch). Whether a stock 4K-page guest kernel boots under the 16K host is untested; `muvm` does exactly that, so it is expected to. |
| `hamtv` | x86-64 | yes | 3.7 GiB (~2.9) | apt: `incus` 6.0.4 | btrfs or dir | **Install** — containers and small VMs |
| `gate` | x86-64 | **no** `/dev/kvm` | 8 GiB (~6) | **none** — OpenWrt's opkg has no Incus | — | **Unavailable**: "Incus isn't packaged for OpenWrt, and this kernel has no KVM." Nothing to install. |

Nothing is installed anywhere today: no qemu, libvirt, lxc or incus on any host.

### Detection the tab runs, in order

1. `incus` on `PATH` and its socket answering → **ready**; read pools, networks, instances.
2. Else: a package manager Ham Lab knows (apt, dnf, pacman, apk) that has an `incus`
   candidate → **installable**, with the Install dialog pre-filled (below).
3. Else → **unavailable**, with the reason in one sentence (no package; no root; OpenWrt).
4. Independently: `/dev/kvm` present and openable → VMs offered. Absent → **containers
   only**, said once on the page, and the create form has no VM option.
5. Architecture from `uname -m`, so the image picker only shows images that can run here.
6. Pool driver: `zfs` if the module and tools are present, else `btrfs` (installing
   `btrfs-progs` as part of Install), else `dir`. The dialog says which it picked and why.

## What the tab does (v1)

Mirrors the Docker tab's shape: a list, a detail page, actions that are followed tasks,
destructive ones confirmed by typing the name.

- **Install** — one task that runs *on the selected machine*: install the package(s),
  `incus admin init --preseed` with the layout from the dialog, create the pool and bridge,
  add Ham Lab's user to `incus-admin` (socket access, the `docker`-group shape) and add it
  to the unit's `SupplementaryGroups`, apply the Docker fix where Docker is present (below),
  then restart Ham Lab. Idempotent, so it doubles as "repair". The dialog shows and lets him
  edit: pool driver (detected), pool size (proposed from free space), bridge subnet
  (computed), whether to apply the Docker rules. Where it all goes is not a choice: Ham
  Lab's folder.
- **Instances** — containers and VMs in one list: type, state, IPv4, CPU and memory live,
  disk, snapshot count, uptime. Click for detail.
- **Create** — container or VM (VM only where KVM is); image from the `images:` remote,
  filtered to this architecture, searchable, with the common ones pinned (Debian 13, Ubuntu
  24.04, Alpine, Fedora); name, CPUs, memory (with this machine's free memory beside it),
  root disk size; network (the NAT bridge, or a LAN bridge if this machine has one);
  optional cloud-init user-data (SSH key, packages, a first command); profile. Create, or
  create and start. Collisions (name taken) named before Create.
- **Lifecycle** — start, stop, restart, force stop, rename, delete (type the name; the
  instance's snapshots go with it, and the dialog says so).
- **Console** — two buttons, both open as tabs in the Terminal page through the existing PTY
  manager (`term.CreateCmd`, the `docker exec` path): **Console** (`incus console`, the
  serial console — works before the network is up, shows boot output) and **Shell**
  (`incus exec <n> -- login shell`). Containers and, via `incus-agent`, VMs.
- **Snapshots** — take, restore (confirmed), delete; a **schedule** per instance with an
  expiry, which is Incus's own `snapshots.schedule`/`snapshots.expiry`, so no cron file of
  ours this time.
- **Resources** — edit CPU and memory limits (live for containers; VMs take CPU hotplug and
  memory balloon live with the agent, else on restart), grow the root disk, add a bind mount
  (a host path into a container; virtiofs into a VM).
- **Library** — ISOs for VMs and images (container templates and VM images). Its own
  section below.
- **Storage and networks** — the pools with their fill, the bridges with their subnets.
  Read-only in v1 beyond what Create and Install need.
- **Sensors** — `instance.<name>.cpu`, `.memory`, `.running` from Incus's state, like the
  `container.*` sensors, so Alerts gets an "instance down" default and widgets can show one.

## Where the data lives

One tree per machine, under Ham Lab's data directory, created by Install:

```
~/apps/hamlab/virt/
  pool.img          the instance pool's backing file (zfs or btrfs loop; a plain directory
                    pool/ when the driver is dir) — every instance's disks live in here
  isos/             the ISO library: the files themselves
  images/           the image library: template tarballs and VM disk images as files, the
                    way Proxmox keeps CT templates — Incus's image store is loaded from here
  exports/          nightly `incus export` tarballs, with retention
  virt.json         what Ham Lab chose and when: driver, pool size, bridge subnet, ISO and
                    image inventory, export schedule
```

Consequences, stated once:

- The tree is on whatever disk holds Ham Lab's data directory — the boot NVMe on all three.
  Install proposes the pool size from that disk's free space. On `grid` that disk has
  790 GiB free; on `core`, 175 GiB.
- Bulk data a guest needs is **bind-mounted in from where it already is** (`/tank/…` into an
  instance on `grid`), the same split Docker has: the instance is Ham Lab's, the media is
  not. That is a device on the instance, recorded in its config, not a second home.
- On `core` the whole tree rides the existing nightly rsync to `grid` for free. On `grid`
  and the Mac it is as backed up as the rest of their Ham Lab folders — which is to say the
  exports are the backup, and the backup job will need to be told about them in phase 2.
- Existing material elsewhere — the 105 GiB of ISOs at `/tank/software/isos/`, the Proxmox
  archives — is **imported into the tree by copying**, file by file, on request. The
  library never indexes a folder it does not own.

## Library: ISOs and images (asked for 2026-10-09)

Proxmox has a storage view with **ISO Images** and **CT Templates**. Incus has the same two
things under other names, and the tab gives them one home, a **Library** sub-tab, per machine
like everything else.

| Proxmox calls it | Incus calls it | What it is here |
|---|---|---|
| ISO Images | an ISO file attached to a VM as a `disk` device (added as a ROM device; VMs only), or a custom storage volume of type `iso` | **`virt/isos/` in Ham Lab's folder**, attached by path — no copy into the pool |
| CT Templates | **images** — the `images:` remote (linuxcontainers.org), the local image store, anything imported or published | **`virt/images/` in Ham Lab's folder** — tarballs and disk images as files, loaded into Incus from there; the remote is the catalogue to pull from |

### ISOs

- **The ISO library is `virt/isos/` in Ham Lab's folder**, on every machine, full stop. The
  105 GiB at `/tank/software/isos/` on `grid` (`linux/`, `windows/`, `truenas/`,
  `virtio_drivers/`…) is a *source* to import from — pick the ones wanted, Ham Lab copies them
  in — not the library itself.
- **Getting an ISO in:** upload from the browser (the Files tab's `PUT /api/files/upload`
  with its progress bar, reused), **download from a URL** as a followed task with an optional
  checksum (the usual way — an ISO starts as a link), or **import from a path** already on the
  machine — which **copies** the file into `virt/isos/` and says so. Rename, delete (refused while a VM has it attached, naming the VM).
- **Using one:** attach to / detach from a VM as a ROM device by path, with `boot.priority`
  set so it boots first; **New VM from ISO** makes an empty VM (`incus init --empty --vm`)
  with the ISO attached, starts it and opens the console. After install, Detach is one click
  and boot order falls back to the disk.
- **Honest limit:** an ISO install is an interactive graphical installer, so it needs the
  **VGA console in the browser** (`spice-html5` over Incus's VGA console websocket).
  Installers that run on a serial console (Debian with `console=ttyS0`, Alpine, Arch) work
  through the text console before that exists. Windows needs the virtio drivers ISO attached
  as a second ROM device as well — Incus's documented path is `distrobuilder repack-windows`
  to bake them in; the drivers are already in `virtio_drivers/` on `tank`. So **the ISO shelf
  and the VGA console ship together, in phase 2**, moved up from phase 3.
- ISO *volumes* (`incus storage volume import <pool> <iso> <name> --type=iso`) are the
  alternative: read-only, attachable to several VMs at once, but they copy the file into the
  pool. Not used here — a file in `virt/isos/` is already Ham Lab's, and a volume would copy it
  a second time into the pool. Offered as an option only if a need shows up.

### Images (container templates and VM images)

- **The catalogue:** browse `images:` filtered to this machine's architecture, by type
  (container / VM), with the common ones pinned. **Download** copies one into the local
  store (`incus image copy images:debian/13 local: --alias debian-13`) so a later Create is
  instant and works without the internet. Images used by Create are cached by Incus anyway;
  this is just the explicit version, Proxmox's "Templates → Download".
- **The local store:** every image here with alias, type, arch, size, origin (remote,
  published, imported), when it was last used, and **which instances were made from it**
  (Incus records the base image on each instance). Alias, delete (refused while an
  instance's base — Incus knows), "New instance from this image".
- **Import:** a unified tarball or metadata + rootfs pair (a container template from
  anywhere, including the phase-3 Proxmox conversions), or a **qcow2 / raw disk with
  metadata Ham Lab writes** for a VM image — Home Assistant OS, OPNsense, a vendor cloud
  image — by upload, URL, or a path on the machine. Same three ways in as ISOs.
- **Publish:** a stopped instance becomes an image with an alias — Proxmox's "convert to
  template", the one thing the Images section of v1 always had.
- **Where they live:** as files in `virt/images/` — the downloaded or imported tarball, the
  published image exported to one (`incus image export`) — so the library is complete without
  Incus and can be reloaded into a fresh install. Incus's own image store under
  `/var/lib/incus/images/` is a cache derived from it, and the page says so.

## Not in v1, with reasons

| Thing | Why not yet |
|---|---|
| **VGA console in the browser** | Incus hands the VM's SPICE socket over a websocket; drawing it needs `spice-html5` in the UI. Doable (the Incus UI does it); text console + shell cover every Linux guest until then. **Phase 2, with the ISO shelf** — an ISO install is useless without it. |
| **Windows VMs** | Incus runs them (ISO repacked with virtio drivers by `distrobuilder`), but without a VGA console in the browser they are unusable from the tab. After the above. |
| **GPU passthrough to a VM** | Removes the card from the host and from whatever uses it there (Jellyfin on `grid`). Offered only with that warning, later. Sharing a GPU into a *container* (`gpu` device) leaves the host its card and is how `r720-jellyfin` used to run. Phase 3. |
| **Clustering / live migration** | Incus clusters, but these machines differ in size and one is arm64, with no shared storage. Not planned. |
| **A fleet-wide instance list** | One machine per view. The switcher is the machine. |
| **A second engine (bare LXC on OpenWrt, libvirt-only hosts)** | Would double the backend for one router that has no KVM. The tab reports Incus unavailable there and stops. |

## Layout decisions Ham Lab makes per machine (overridable in the Install dialog)

1. **Storage.** The instance pool's backing lives in Ham Lab's folder: Install creates a
   sparse `virt/pool.img` and hands it to Incus as the pool's `source` (zfs or btrfs by the
   detection above), or `virt/pool/` as a `dir` pool where neither is available. Sized from
   the disk's free space, shown and editable. Bulk data is **bind-mounted in**, not stored in
   the pool. The driver, path and size are recorded in `virt.json` so the page can say where
   the data is and Install can rebuild the pool from the file after a reinstall.
2. **Bridge subnet, computed.** Incus's `auto` picks a random `10.x.y.0/24`, and **this
   LAN is `10.0.0.0/8`** — every host has a /8 on its NIC, so any 10.x bridge collides.
   Ham Lab reads the machine's routes and picks the first free /24 from `192.168.0.0/16`,
   then `172.16.0.0/12`, that is neither on-link nor routed nor inside Docker's configured
   pool (`172.28.0.0/14` on `grid`; `172.19`–`172.29` and `192.168.80`–`143` live on
   `core`). Instances get `name.incus` DNS from Incus's dnsmasq.
3. **LAN addresses are a later, explicit step.** A `br0` on the machine's uplink lets an
   instance take a lease from `gate` and a Pi-hole name, but it rewrites the host's network
   config and drops it off the network for seconds — never part of Install, always its own
   confirmed action (with the NanoKVM standing by on `grid`). macvlan was considered and
   rejected: no host change, but host and guests cannot talk, so nothing on the host could
   reach an instance.
4. **Docker and Incus on one host.** Docker sets the `FORWARD` policy to `DROP`, which
   silently kills the Incus bridge's traffic. Fix is two `DOCKER-USER` accept rules for the
   bridge, persisted — applied by Install wherever Docker is detected (`grid`, `core`, the
   Mac, `hamtv` all run it).
5. **Memory.** A VM's memory is a hard reservation; the create form shows the machine's
   free memory and warns past it, and never refuses. On a ZFS host Install offers to cap
   the ARC (on `grid`, 40 GiB → 16 GiB) so guest RAM is deterministic; his choice.
6. **Privilege.** Ham Lab's user joins `incus-admin`; no sudo in the hot path. Install
   itself goes through `priv` like the other installers.
7. **Backups.** Nightly `incus export --instance-only` of every instance to `virt/exports/`
   with a retention, as a cron line like the ZFS schedules (`hamlab incus-export`), from
   phase 2. On `core` that folder is inside the nightly rsync already; on `grid` and the Mac
   the backup job gets a line for it in phase 2.

## The old Proxmox estate (importable, phase 3)

`/tank/backups/proxmox/` holds the retired `r720` node: `/etc/pve` (12 LXC confs, 2 VM
confs), 118 GiB of `vzdump` archives, and three raw VM disks. Latest of each:

| ID | Name | Latest archive | Size |
|---|---|---|---|
| 100 | r720-docker | 2026-01-11 | 20.7 GB |
| 101 | r720-cockpit | 2026-01-11 | 439 MB |
| 102 | r720-wordpress-alexblaskovich | 2026-01-11 | 1.2 GB |
| 103 | r720-spoonterm | 2025-06-14 | 494 MB |
| 104 | r720-ollama | 2026-01-11 | 11.3 GB |
| 105 | r720-transmission | 2026-01-11 | 322 MB |
| 106 | r720-apache | 2026-01-11 | 347 MB |
| 107 | r720-nut | 2025-03-29 | 205 MB |
| 108 | r720-filebrowser | 2026-01-11 | 262 MB |
| 109 | r720-bookstack | 2025-04-27 | 516 MB |
| 110 | r720-jellyfin | 2026-01-11 | 2.2 GB |
| 111 | r720-wireguard | 2025-04-13 | 510 MB |
| 112 | r720-eggwiki | 2026-01-11 | 634 MB |
| VMs | steam (102), powerpanel (105/107/112) | `.vma.zst` 2024–2025; raw disks `vm-105`, `vm-112`, `base-104` | 19 GB, 1.9 GB ×6, 97 GiB |

- **LXC:** feasible and scriptable. Unpack the rootfs (`tar --zstd -xpf … --numeric-owner`),
  read `etc/vzdump/pct.conf` for arch/ostype, drop it, write `metadata.yaml`, pack, `incus
  image import`, launch. Unprivileged uid shifting is Incus's job after that. The result is
  an image in the Library, so a restored container is launched from there like any other
  template. An import action in the tab (pick an archive on this machine) is plausible once
  the script works by hand. x86-64 archives only run on x86-64 machines; the picker says so.
- **VMs:** the raw disks import directly (`incus-migrate`, or an empty VM with the disk
  imported into its root volume). The `.vma.zst` archives need Proxmox's `vma` extractor (or
  the Python port) to become raw disks first. Most of these are the same `powerpanel` box
  backed up six times, and `tank-space-audit.md` already has them down for deletion — decide
  which, if any, are wanted before anything is restored.

## Build plan

| Phase | What | Effort |
|---|---|---|
| **1 — detection, Install, the tab** | `internal/incus` (detection, CLI wrapper, JSON types, `incus monitor` for live state, the preseed builder and subnet picker), `internal/api/virt.go` (routes below), `Virtualization.tsx` (the three page states; list, detail, create dialog, snapshot panel), rail entry `virt`, terminal integration, sensors, and the Library's **Images** shelf (browse and download from `images:`, local store, import, publish). **Tested by clicking Install on `grid` first, then `core`** — two different pool drivers, both with Docker present. Then the Mac for the arm64 path. `gate` for the unavailable state. | 2–3 sessions |
| **2 — operations** | The Library's **ISO** shelf (directory, upload/URL/path, attach, New VM from ISO) **with the VGA console** (`spice-html5`), snapshot schedules UI, nightly exports with retention and the per-machine export directory, limits editor, bind mounts, the LAN-bridge step, instance alert default, cloud-init presets. | 1–2 sessions |
| **3 — the rest** | Proxmox import (archives become Library images), GPU device for containers, Windows via `distrobuilder repack-windows`, GPU passthrough to a VM with its warning. | as wanted |

### API sketch

```
GET    /api/virt                               {state: ready|installable|unavailable, reason, kvm, arch,
                                                pool_drivers[], pools[], networks[], instances[], free_memory}
POST   /api/virt/install                       {driver, size, path, subnet, docker_rules, arc_max?}  task
GET    /api/virt/images?remote=images&q=       local cache + remote search, filtered to this arch
DELETE /api/virt/images/{fingerprint}
POST   /api/virt/instances                     {name, type, image, cpu, memory, disk, network, cloudinit, profile, start}  task
GET    /api/virt/instances/{name}              config, state, devices, snapshots
PATCH  /api/virt/instances/{name}              limits, description, devices
POST   /api/virt/instances/{name}/{start|stop|restart|kill|delete|rename|publish|export}
POST   /api/virt/instances/{name}/console      → terminal {id}   (incus console)
POST   /api/virt/instances/{name}/exec         → terminal {id}   (incus exec -- sh -lc …)
POST   /api/virt/instances/{name}/snapshots    {name}; POST …/{snap}/restore; DELETE …/{snap}
PUT    /api/virt/instances/{name}/schedule     {cron, expiry}
POST   /api/virt/import                        {path}  task (export tarball, or phase-3 Proxmox archive)

GET    /api/virt/isos                          virt/isos/, scanned: name, size, attached-to
POST   /api/virt/isos/import                   {path}  task: copy a file on this machine into virt/isos/
POST   /api/virt/isos/fetch                    {url, sha256?}  task;  uploads reuse PUT /api/files/upload
DELETE /api/virt/isos/{name}                   refused while attached
POST   /api/virt/instances/{name}/iso          {iso, boot_first}  attach;  DELETE …/iso  detach
POST   /api/virt/instances/from-iso            {name, iso, cpu, memory, disk, network}  task → console
GET    /api/virt/images/remote?q=&type=        the `images:` catalogue for this arch
POST   /api/virt/images/download               {alias}  task (incus image copy images:… local:)
POST   /api/virt/images/import                 {path | url, alias, type}  task: copy into virt/images/, then load into Incus
GET    /api/virt/instances/{name}/vga          websocket: Incus VGA console → spice-html5  (phase 2)
```

Everything is per machine and reaches a node through the existing `/api/nodes/{name}/…`
proxy with no hub-side code; consoles attach over the existing `/api/terminals/{id}/attach`.
Tasks stream through `/api/tasks/{id}/stream` as Docker's do.

## Sources

- Incus on Debian: https://wiki.debian.org/Incus
- Incus and Docker on one host (the `FORWARD` drop): https://linuxcontainers.org/incus/docs/main/howto/network_bridge_firewalld/
- Bridge options and `ipv4.address: auto`: https://linuxcontainers.org/incus/docs/main/reference/network_bridge/
- Consoles (text and VGA): https://linuxcontainers.org/incus/docs/main/howto/instances_console/
- ZFS storage driver: https://linuxcontainers.org/incus/docs/main/reference/storage_zfs/
- macvlan's host-isolation: https://linuxcontainers.org/incus/docs/main/reference/network_macvlan/
- Image format for the Proxmox import: https://linuxcontainers.org/incus/docs/main/reference/image_format/