cv4pve-cli-tui/docs/plans/guest-tui-mvp.md

# Guest TUI MVP

## Problem

Manage Proxmox guests (VMs and LXC containers) from the terminal without remembering
`cv4pve-cli` syntax: list them, start/shutdown/stop/reboot, and change CPU cores,
memory and disk size.

## Approach

Thin subprocess wrapper around `cv4pve-cli` (tested against 2.4.0) plus a Textual app.
The app never handles credentials: it uses whatever context `cv4pve-cli config use`
selected.

Observed CLI behaviour the design relies on:

- `get guests -o json` -> list of dicts with `vmid`, `type` (`qemu`|`lxc`), `node`,
  `name`, `status`, `maxcpu`, `maxmem` (bytes), `maxdisk` (bytes), ...
- `show vm|ct <node> <vmid> -o json` -> list of `{"key": ..., "value": ...}`.
- `api get /nodes/<node>/<qemu|lxc>/<vmid>/pending -o json` -> list of
  `{"key", "value", "pending", "delete"}`; `pending` non-null means not yet applied.
- Async actions print a UPID and exit 0 **even when the task fails**. With `--wait`
  the CLI waits for the task and exits non-zero (5) with the error text on failure.
  Every mutating call therefore uses `--wait`.
- `do stop` refuses to run without `-y` (verified); `-y` is accepted by all four
  lifecycle actions, so it is always passed.
- Errors: non-zero exit, message on stdout/stderr. Sync failures are multi-line
  (`Error: ...` / `Call: ...` / `Alias: ...`). Success is judged by exit code only,
  never by parsing UPID text.
- Each call costs ~0.5 s (.NET startup), so calls run in worker threads.
- `get guests` (`/cluster/resources`) lags a few seconds behind actions; after an
  action the app reads the acted-on guest's live status from
  `api get /nodes/<node>/<qemu|lxc>/<vmid>/status/current` (key/value list).

### Module `cv4pve_tui/cli.py`

- `CliError(Exception)` - `str()` is the CLI's combined, stripped output;
  `.summary` is one line for the UI: the first non-empty line that is not a UPID,
  `Error:`-prefix stripped, plus the following indented detail line if the first
  line ends with `:`.
- `run(*args) -> str` - `subprocess.run(["cv4pve-cli", *args], capture_output=True,
  text=True, stdin=DEVNULL, timeout=330)`; non-zero exit -> `CliError`.
- `kind(guest) -> "vm" | "ct"` - from `type` (`qemu` -> `vm`, `lxc` -> `ct`).
- `list_guests() -> list[dict]` - sorted by `vmid`.
- `guest_config(guest) -> dict` - key/value list flattened to a dict.
- `disks(config, kind) -> dict[str, str]` - resizable disks -> size string.
  VM: `scsiN|virtioN|sataN|ideN` with a `size=`, excluding `media=cdrom` and
  cloud-init. CT: `rootfs`, `mpN`.
- `ACTIONS = ("start", "shutdown", "stop", "reboot")`;
  `action(name, guest)` -> `do <name> <kind> <node> <vmid> -y --wait`;
  unknown name -> `ValueError`.
- `set_resources(guest, cores=None, memory_mb=None)` ->
  `set <kind> config <node> <vmid> [--cores N] [--memory M] --wait`; values must be
  positive ints; nothing to set -> `ValueError`.
- `resize_disk(guest, disk, grow_gb)` -> `do resize <kind> disk <node> <vmid> <disk>
  +<grow_gb>G --wait`; `grow_gb` must be a positive int (growth only - Proxmox cannot
  shrink, and an increment cannot shrink by construction).
- `pending_keys(guest) -> list[str]` - keys with a non-null `pending`.

### Module `cv4pve_tui/app.py`

- `DataTable` of guests: VMID, name, type, node, status, cores, memory (MiB),
  disk (GiB). Cursor row = selected guest.
- Keys: `s` start, `S` shutdown, `x` stop (hard), `r` reboot, `e` edit,
  `g` refresh, `q` quit.
- `shutdown`, `stop`, `reboot` open a confirm modal naming the guest; `stop` says it
  is a hard power-off. `start` needs no confirmation.
- `e` opens an edit modal: cores, memory MiB, disk select + "grow by GiB".
  Empty field = unchanged. Disk growth gets its own confirm (irreversible).
- After `set_resources`, if `pending_keys` contains `cores` or `memory`, notify that
  the change applies at next reboot.
- All CLI calls in thread workers; results/errors via `notify` (errors show
  `CliError.summary`); table refreshes after each action.
- A "working" notice is shown when an action starts (`--wait` can block minutes),
  and a second action on a guest that is already busy is refused.
- Action keys on an empty table do nothing (no crash).

### UI contract (shared by tests and implementation)

- `app.py` does `from cv4pve_tui import cli` and always calls `cli.<function>(...)`,
  so tests monkeypatch `cv4pve_tui.cli.<function>`.
- `class GuestApp(App)`; `def main()` runs it.
- Guest table: `DataTable` with id `guests`, one row per guest, row key = str(vmid),
  in `list_guests()` order. Loaded on mount.
- `ConfirmScreen(ModalScreen[bool])`: buttons `#yes` / `#no`; its text names the guest
  (name and vmid); for `stop` it contains the words "hard power-off".
- `EditScreen(ModalScreen)`: `Input#cores`, `Input#memory`, `Select#disk`,
  `Input#grow`, buttons `#apply` / `#cancel`. Inputs are pre-filled with nothing
  (empty = unchanged); placeholders show current values. Disk options come from
  `cli.disks(cli.guest_config(guest), cli.kind(guest))`.
  On apply: if cores/memory given -> `cli.set_resources(guest, cores=..., memory_mb=...)`
  (only the given ones, as ints); if grow given -> `ConfirmScreen` first, then
  `cli.resize_disk(guest, disk, grow_gb)`. Non-integer or <= 0 input -> `notify`
  with severity "error" and no CLI call.
- Thread workers (`@work(thread=True)` or `run_worker(..., thread=True)`); tests wait
  with `await app.workers.wait_for_complete()` then `await pilot.pause()`.

## Out of scope

Create/delete, snapshots, migration, console, backup, in-app context switching,
sockets/vCPU/hotplug settings, live auto-refresh.

## Steps

- [x] Project skeleton (`uv`, `pyproject.toml`, entry point `cv4pve-tui`) -
      `uv run python -c "import cv4pve_tui"` succeeds.
- [x] Tests for `cli.py` with `subprocess.run` mocked - fail before implementation.
- [x] `cli.py` - tests pass.
- [x] Tests for the app with Textual `run_test` and `cli` functions mocked.
- [x] `app.py` - tests pass.
- [x] Read-only smoke test against the real cluster (listing, edit dialog disk options,
      pending check).
- [x] Live edit (cores/memory), shutdown, start, reboot on CT 104 (mainframe), restored
      to baseline afterwards. Disk resize not run live (irreversible).

## Open questions

None blocking.

---

# Context switching

## Problem

Several cv4pve-cli contexts (clusters) exist; switch between them inside the TUI
instead of quitting and running `cv4pve-cli config use`.

## Decision

Option A: switching runs `cv4pve-cli config use <name>`, which changes the **global**
current context (all shells and scripts follow) and stays after the app exits. cv4pve-cli
2.4.0 has no per-call context flag or env var (verified), so there is no app-local option.

Observed CLI behaviour:

- `config list` has no `-o json`. Text output, one line per context; current one
  prefixed with `* `, others with two spaces:
  `* mainframe            mainframe.iot.home.arpa:8006   (api-token)`
  `  mainframe-edge       mainframe-edge.home.arpa:8006   (api-token)`
- `config use <name>` -> exit 0 on success; unknown name -> exit 3,
  `Error: Context '<name>' not found.`, current context unchanged.

### `cli.py`

- `contexts() -> list[dict]` - `run("config", "list")`, each line parsed to
  `{"name", "host", "auth", "current": bool}` (regex
  `^(\*)?\s*(\S+)\s+(\S+)\s+\((.*)\)\s*$`); non-matching lines are ignored.
- `use_context(name)` - `run("config", "use", name)`.

### `app.py` (UI contract)

- The active context is always visible: `app.sub_title == f"context: {name}"`
  (shown in the Header). Set on mount from `cli.contexts()` and after every switch.
  If `contexts()` fails: error notify, sub_title `context: ?`.
- Key `c` opens `ContextScreen(ModalScreen[str | None])` with `OptionList#contexts`,
  one option per context, option id = context name, current one marked with `*`.
  Selecting an option dismisses with its name; `escape` dismisses with `None`.
- `c` while any guest is busy -> warning notify, no screen (VMIDs collide across
  clusters, so the busy guard would point at the wrong cluster).
- Selecting the current context or dismissing -> no CLI call.
- A reload started before a switch must not refill the table (generation counter);
  `g` and `c` are refused while a switch runs; the post-action reload finishes before
  the guest stops being busy.
- Selecting another context: table cleared immediately (old cluster's guests must not
  stay actionable), then in a worker `cli.use_context(name)`, sub_title updated, guests
  reloaded. On `CliError`: error notify with summary, sub_title re-read from
  `cli.contexts()`, guests reloaded.

## Out of scope

Adding/editing/deleting contexts, `config verify`, restoring the original context on exit.

## Steps

- [x] Tests for `contexts`/`use_context` and the UI contract above - red first.
- [x] Implementation - full suite green, ruff clean.
- [x] Live: open the list, switch to `mainframe-edge` and back to `mainframe`
      (only `config use` and read-only listing; no guest actions); final context
      is `mainframe`.
- [ ] Push `feat/guest-tui-mvp`, merge to `main` (user-approved).

---

# LXC shell

## Problem

Open an interactive shell in a running LXC container from the TUI. cv4pve-cli 2.4.0 has
no console/shell/exec for LXC (verified: no command; the Proxmox API has no LXC exec),
so the app goes around it: SSH to the PVE node as root and run `pct enter <vmid>`.

## Decision

Option 1 from the discussion: `ssh -t root@<node> pct enter <vmid>`. The node name is
the SSH host (resolves via DNS here: `mainframe`, `mainframe-edge`); the user's key is in
root's `authorized_keys` (verified: `ssh -o BatchMode=yes root@mainframe pct status 104`
-> `status: running`). This bypasses cv4pve-cli and its API token.

## `app.py` (UI contract)

- Key `t` ("Shell") on the selected guest.
- Only for `type == "lxc"` and `status == "running"`; otherwise a warning notify that
  says why (not a container / not running) and nothing runs. Empty table: nothing.
- Busy guest (action running) -> warning notify, nothing runs.
- Runs on the main thread inside `with self.suspend():` -
  `subprocess.run(["ssh", "-t", f"root@{node}", "pct", "enter", str(vmid)])`
  (no capture, no timeout: the user's terminal is handed over; `import subprocess` in
  app.py so tests patch `cv4pve_tui.app.subprocess.run`).
- Exit 255 (ssh itself failed) -> error notify naming the guest and the code. Other
  exit codes are the container shell's last status (`exit` after a failed command
  gives 1) and are not errors.
- Inside `suspend()`, right before ssh, the terminal gets a full reset (`ESC c`, what
  `reset` sends) so the container shell starts on a clean screen without leftover TUI
  terminal modes (user request). Done locally, not in the container: no dependency on
  `reset` existing there, and `pct enter` stays unchanged.
- `OSError` from `subprocess.run` is caught *inside* the `suspend()` block: Textual
  8.2.8's `suspend()` has no try/finally, so an exception escaping it leaves the app
  suspended.
- The guest table reloads after the shell returns (the user may have stopped or
  rebooted the container from inside).
- `textual.app.SuspendNotSupported` (headless / unsupported driver) and `OSError`
  (no `ssh` binary) -> error notify, app keeps running.
- Tests: `App.suspend` raises `SuspendNotSupported` under `run_test`, so tests replace
  `app.suspend` with a no-op context manager (e.g. `contextlib.nullcontext`) unless
  testing that error path.

## Out of scope

VM consoles (serial/VNC), configurable SSH user/host/options, termproxy/websocket.

## Steps

- [x] Tests for the UI contract above - red first.
- [x] Implementation - full suite green, ruff clean. README key table gets `t`.
- [ ] Interactive test by the user: `t` on CT 104, `exit`, back in the table.
- [ ] Push `feat/lxc-shell`, merge to `main` (user-approved).