Plan doc for gh #482 + the tunnelled-maddr item of #443. Pushes
back on the framing that `wg` is a tpt: it's transparent to
`socket(2)`, so it belongs as a *bindspace* — a scoped
`@acm`-managed net ctx that an existing L4 tpt binds *inside* —
and it's what finally implements the long-spec'd (never
implemented) `Address.namespace`.
Deats, 3 independently-shippable layers,
- A) declarative: commit #482's examples, teach `parse_maddr()`
the `/…/wg/u<key>` suffix -> a `TunnelledAddress` wrapper whose
`.proto_key`/`.unwrap()` delegate to `.inner` so nothing new
crosses the wire and every existing table lookup keeps working.
- B) swap the `subprocess.run(['sudo', 'wg', 'show'])` shelling
for `pyroute2`. Default to `trio.to_thread` around the sync API
(these are one-shot ops at bind/teardown, never hot-path), w/
sans-io codecs + a trio `AF_NETLINK` sock as the follow-up for
the read paths. Explicitly forbids dragging `trio-asyncio` in.
- C) `open_bindspace()`/`open_netns()`/`open_wg_iface()` `@acm`s
folded w/ an `AsyncExitStack`, + filling in the
`# !TODO, always be ns aware!` placeholder already sitting in
`Endpoint.pformat()`.
Also flags the subtlest bug in the whole thing: `setns(2)` is
*per-thread*, so a `pyroute2` query issued via `trio.to_thread`
lands in the *original* netns. Test-first, per usual.
Further, designs for the generalization (`TunnelSpec` union +
`match` dispatch) while only implementing `wg`+netns, and calls
out `veth`-in-netns as the better *first* one bc it makes a
fully self-contained two-"host" integration test possible w/o
`wg` at all.
(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))
Gud Boi