docs(gateway): describe what is, not what changed

Per review: docs represent current state. Every "used to" / "no longer"
clause this branch introduced is gone — including the History section in
network.md, which was a whole subsection about a sync mechanism that
doesn't exist.

Where the removed clause was carrying a real constraint, the constraint
stays and is stated in the present tense instead of as a delta: nothing
narrows what the gateway's nginx can reach except the directory
permissions in front of a socket, and nothing bounds `ReloadGatewayNginx`
except the hard-coded unit name. Those read as rules now rather than as
the story of how they came to be rules.

docs/boundary.md

@@ -121,25 +121,18 @@ The mode is load-bearing, not cosmetic. Write permission on a
 them, and the sticky bit is the only thing that would restrain that (it
 is not set here). A world-writable socket dir therefore lets anything
 able to reach the path delete an agent's socket and bind its own — and
-nginx reaches all of `/run/hive-agent` (as a plain host path since the
-gateway moved out of its container; it used to be bind-mounted in, which
-was the same reach through a longer route). Dropping `o=w` removes that
-permission rather than qualifying it.
+nginx reaches all of `/run/hive-agent` as a plain host path. Dropping
+`o=w` removes that permission rather than qualifying it.
 
-⚠️ **The gateway leaving its container is a deliberate trade, recorded
-here so it is not mistaken for an oversight.** nginx and dnsmasq run on
-the host next to `hive-c0re` (see `docs/gateway.md`). What was given up
-is a *mount/pid* namespace — **not** a network one: that container ran
-with `privateNetwork = false` and shared the host's netns, so nginx was
-already binding host ports and already reaching `localhost` upstreams.
-The boundary bought no network isolation while costing a resolv.conf
-sync, a reload that had to cross the machine bus, and three bind mounts.
-🔑 It did cost one real thing, and the replacement is explicit: the
-privileged reload verb used to be scoped by `--machine=hive-gateway`,
-which could only ever reach into that one container. With no namespace
-to bound it, the unit name is hard-coded in `hive-priv` instead — see
-`PrivRequest::ReloadGatewayNginx`. **A caller cannot name the unit, so
-the verb cannot be steered at another service.**
+⚠️ **The gateway's nginx and dnsmasq are host services, next to
+`hive-c0re`** (see `docs/gateway.md`) — there is no namespace between
+them and the rest of the host. That costs no network isolation: nginx
+binds the host's `:80`/`:443` and reaches `localhost` upstreams, which a
+netns would have to be opened up for anyway.
+🔑 It does mean nothing *implicitly* scopes the privileged reload verb,
+so the scope is explicit: the unit name is hard-coded in `hive-priv` —
+see `PrivRequest::ReloadGatewayNginx`. **A caller cannot name the unit,
+so the verb cannot be steered at another service.**
 
 ⚠️ Contrast `/shared`, which *is* sticky world-writable (`1777`): it has
 many legitimate writers, so sticky is the best available answer there.

docs/gateway.md

@@ -122,12 +122,9 @@ now set unconditionally for every agent. The mechanism:
    - failed → `systemctl reset-failed nginx` + `systemctl start nginx`
    - otherwise → `systemctl start nginx`
    This is an explicit trigger rather than a path unit watching the
-   file. It used to be *impossible* to do it any other way — `IN_MOVED_TO`
-   from the atomic rename did not cross the nspawn mount-namespace
-   boundary, so an in-container path unit never fired. With nginx on the
-   host a path unit would now work, and it is still not wanted: the write
-   and the reload belong in one causal chain c0re can retry and report on
-   (`RELOAD_PENDING`), not two units racing on an inotify event.
+   file: the write and the reload belong in one causal chain c0re can
+   retry and report on (`RELOAD_PENDING`), not two units racing on an
+   inotify event.
 
 c0re regenerates `agents.conf` (and triggers a reload) on two
 triggers: every topology change (new/removed agents) and every 10s
@@ -200,7 +197,7 @@ On by default, and listens on `httpsPort` (default 443) on every vhost beside th
 
 The issuer is a **host-held hive CA**, not a bare self-signed leaf. A host service (`hive-tls-ca.service`, from the `hive-tls` module) generates a long-lived CA (`services.hyperhive.tls.caValidityDays`, default ~20y) under `services.hyperhive.tls.stateDir` (default `/var/lib/hive-tls`), then signs a gateway **leaf** (`leafValidityDays`, default 30d) with it. `hive-gateway-self-signed-cert` then imports the leaf into nginx's state dir (`/var/lib/hive-gateway/tls/{cert,key}.pem`).
 
-⚠️ **That import unit is not a leftover of the old container — do not collapse it into pointing nginx at the CA dir.** It does two jobs. It re-modes the leaf (`hive-tls-ca` writes the key `0600 root:root`; nginx's pre-start `nginx -t` runs as the *nginx user*, so a `0600` key fails the config test and blocks the unit), and it guarantees **every cert path the nginx config names exists** — which is what the swarm-services fallback below is for. Removing it re-creates the #3097 outage.
+⚠️ **Do not collapse that import unit into pointing nginx at the CA dir.** It does two jobs. It re-modes the leaf (`hive-tls-ca` writes the key `0600 root:root`; nginx's pre-start `nginx -t` runs as the *nginx user*, so a `0600` key fails the config test and blocks the unit), and it guarantees **every cert path the nginx config names exists** — which is what the swarm-services fallback below is for. Removing it re-creates the #3097 outage.
 
 **Why a CA, not a bare leaf**: a bare self-signed leaf is its own trust anchor, so every regeneration is a new anchor every consumer must re-trust — and a runtime-generated leaf can't be wired into an agent's build-time trust store at all. With a stable CA, agents and federation peers trust it *once*; leaf rotation never re-breaks them.
 
@@ -433,9 +430,7 @@ any content change — so `max-age=31536000` is safe.
 **Why the nix store path resolves**: `HIVE_AGENT_FRONTEND_DIR` is a nix
 store path baked in at hive-c0re build time, and c0re (writing
 `agents.conf`) and nginx (serving files from it) are on the same machine,
-so they see the same store. This used to need explaining — nspawn
-bind-mounts `/nix/store` read-only into a container, which is what made
-the baked-in path work from inside the gateway.
+so they see the same store.
 
 **Graceful degradation**: if `HIVE_AGENT_FRONTEND_DIR` is empty or
 unset (e.g. a build that predates `cfg.frontend`), each agent gets the

docs/network.md

@@ -124,37 +124,10 @@ There is deliberately no fallback `server=`: dnsmasq queries all known
 upstreams in parallel, so a hardcoded public resolver would take a share
 of normal traffic, not just cover the gap.
 
-### History: the resolv.conf sync, and why it is gone
-
-Until the gateway moved onto the host, dnsmasq ran in the `hive-gateway`
-container and read *that* container's `/etc/resolv.conf` — a one-shot
-copy nixos-container made at start. systemd-nspawn(1) is explicit that
-nothing propagates into it after early init, because resolv.conf is
-normally updated by rename rather than in place. So a host network change
-(new router, new lease, laptop moving networks) stranded dnsmasq on a
-resolver that no longer answered, and every non-hive lookup from every
-agent hung until someone restarted the gateway.
-
-A host-side `hive-gateway-resolv` path unit closed that gap: watch
-`/etc/resolv.conf`, `machinectl copy-to` it into the container, reload
-dnsmasq. Roughly eighty lines of watcher, marker file, is-active guard
-and mid-rewrite-snapshot check — **all of it bridging two copies of one
-file.** With one machine there is one file, and the whole unit is
-deleted.
-
-🔑 Worth keeping as a shape, not just a story: **the sync was not
-complexity anyone chose. It was the cost of a boundary that bought
-nothing here** — the gateway already ran with `privateNetwork = false`,
-sharing the host's netns, so the container never provided network
-isolation in the first place. When a workaround is that elaborate, the
-question to ask is what the boundary is *for*.
-
-(Two alternatives were considered at the time and both were worse than
-the copy: a path unit *inside* the container never fired, because the
-host replaces the file by rename and `IN_MOVED_TO` does not cross the
-nspawn mount namespace; and bind-mounting the host's `/etc/resolv.conf`
-would have pinned the *first* inode for the container's whole lifetime,
-since openresolv writes a temp file and renames over the target.)
+dnsmasq runs on the host and reads the host's `/etc/resolv.conf`
+directly, so a network change (new router, new lease, laptop moving
+networks) reaches it the moment openresolv rewrites the file. There is
+nothing to synchronise and no unit watching for it.
 
 `bind-interfaces` + `interface = [ bridgeName "lo" ]` means the
 listener only accepts queries from the bridge interface (plus lo for

docs/security.md

@@ -191,16 +191,12 @@ directly invoke `nixos-container`, `journalctl -M`, or act on a system
 unit (`systemctl reload nginx`) — those require root. `hive-priv` fills
 this gap.
 
-⚠️ **Note what that costs when a helper verb loses its namespace.**
-`ReloadGatewayNginx` used to run `systemctl -M hive-gateway …`, and the
-`--machine=` flag was doing two jobs: it was the *transport* into the
-container **and** the *scope* — the verb could not reach anything
-outside that one machine. With nginx on the host the transport is
-unnecessary and the scope went with it, so the containment is now the
-hard-coded unit name in `hive-priv`: a caller cannot name the unit, so
-the verb cannot be steered at another service. **When a privileged verb
-stops needing a namespace, check whether the namespace was also what
-bounded it.**
+⚠️ **`ReloadGatewayNginx` acts on a host unit, so nothing implicitly
+scopes it.** Its containment is the unit name hard-coded in `hive-priv`:
+a caller cannot name the unit, so the verb cannot be steered at another
+service. **A privileged verb needs something bounding what it can act
+on; when that isn't a namespace, it has to be a constant the caller
+can't supply.**
 
 ### hive-priv
 

hive-agent/src/web_ui/mod.rs

@@ -172,9 +172,8 @@ pub async fn serve(
 /// `0o666` — world-accessible so the gateway's nginx process can
 /// `connect(2)` without sharing a group with the agent user. What bounds
 /// that is the per-agent subdir (`/run/hive-agent/<name>/`): the socket
-/// mode grants everyone, the directory decides who gets to ask. It used
-/// to be bind-mounted into the one container that needed it; nginx is a
-/// host unit now, so the directory's own permissions are the whole story.
+/// mode grants everyone, so the directory's permissions decide who gets
+/// to ask.
 ///
 /// Marker-gating + the gateway-side consumer: see
 /// [`docs/gateway.md::Per-agent unix-socket upstream`](../../../docs/gateway.md).

hive-c0re/src/dashboard/infra_containers.rs

@@ -5,9 +5,9 @@
 //! is reached from the dashboard — already fully operator-authenticated —
 //! so no capability check is needed here, just the same audit trail.
 //!
-//! The two surfaces no longer cover the same set: the gateway is the
-//! operator's to restart and not an agent's, since nginx on the host fronts
-//! every hive service. This endpoint keeps all four.
+//! The two surfaces cover different sets: this endpoint takes all four,
+//! while the agent path refuses the gateway — nginx on the host fronts
+//! every hive service, so bouncing it is the operator's call.
 
 use axum::{
     extract::{Path as AxumPath, State},

hive-c0re/src/dashboard/journal.rs

@@ -193,8 +193,7 @@ pub(super) async fn get_journal_host(
     axum::extract::Query(q): axum::extract::Query<JournalHostQuery>,
 ) -> Result<Response, ProblemDetails> {
     let lines = q.lines.unwrap_or(500).min(5000);
-    // `nginx.service` is the gateway: its logs used to live in the
-    // hive-gateway container's journal and are host-side now.
+    // `nginx.service` is the gateway — its logs are host-side.
     let allowed = ["hive-c0re.service", "hive-priv.service", "nginx.service"];
     let unit = match q.unit.as_deref().filter(|s| !s.is_empty()) {
         Some(u) => {

hive-c0re/src/gateway_nginx.rs

@@ -167,16 +167,12 @@ fn render(names: &[String], frontend_dir: Option<&str>) -> String {
 /// After a successful write, triggers the appropriate nginx action via
 /// `hive-priv` (hive-c0re runs unprivileged and cannot act on a system
 /// unit): reload when nginx is active, reset-failed+start when in a
-/// failed state, plain start otherwise. Writer and nginx are now on the
-/// same machine, so this is a plain unit action rather than the old
-/// `systemd-run --machine=hive-gateway` hop across the container
-/// boundary. It stays an explicit trigger rather than a systemd path
-/// unit watching the file. A path unit would now *work* — `IN_MOVED_TO`
-/// (fired by the atomic rename) failed to propagate across the nspawn
-/// mount-namespace boundary, and that boundary is gone — but it is still
-/// not wanted: the write already knows it changed something, and a
-/// watcher turns one causal edge into a race with the writer's own
-/// rename (see `docs/gateway.md`).
+/// failed state, plain start otherwise. Writer and nginx are on the same
+/// machine, so it is a plain unit action with no machine-bus hop.
+/// It stays an explicit trigger rather than a systemd path
+/// unit watching the file: the write already knows it changed something,
+/// and a watcher would turn one causal edge into a race with the writer's
+/// own rename (see `docs/gateway.md`).
 ///
 /// The priv call is best-effort — a failed sync is logged but not fatal.
 /// `reload_if_pending` retries on the next `spawn_poll` tick so a

hive-c0re/src/paths.rs

@@ -219,11 +219,11 @@ pub fn shared_root() -> PathBuf {
 pub const KNOWLEDGE_DIR: &str = "/var/lib/hyperhive/knowledge";
 
 /// `gateway/` — generated nginx include fragments for the gateway vhost.
-/// nginx runs on the host and reads this path directly; it used to be
-/// bind-mounted into a gateway container at `/run/hive-state/`, exposing
-/// this subdir *only* so the rest of `/var/lib/hyperhive/` (forge/matrix
-/// tokens, etc.) stayed out of reach. On the host that narrowing is the
-/// unit's sandbox, not a mount — nginx is not confined by this path.
+/// nginx runs on the host and reads this path directly. ⚠️ Nothing about
+/// this path confines it: what keeps nginx away from the rest of
+/// `/var/lib/hyperhive/` (forge/matrix tokens, etc.) is the unit's own
+/// sandbox, so widening that sandbox widens what a gateway compromise
+/// reaches.
 // nix: named by the gateway's nginx config (hive-gateway/vhosts.nix) — must match.
 #[must_use]
 pub fn gateway_dir() -> PathBuf {

hive-c0re/src/workers/agent_sockets.rs

@@ -14,11 +14,10 @@ use std::path::{Path, PathBuf};
 use anyhow::{Context, Result};
 
 /// Host-side parent directory holding per-agent socket subdirs. The
-/// gateway's nginx runs on the host and reads this whole tree, so it
-/// can `proxy_pass` to any agent — it used to get there through a
-/// read-only bind-mount of the same tree. Each agent's container
-/// bind-mounts only its own `<name>/` subdir, which is still what stops
-/// one agent reaching another's socket. The literal lives in `hive-host-sock` (shared with
+/// gateway's nginx runs on the host and reads this whole tree, so it can
+/// `proxy_pass` to any agent. Each agent's container bind-mounts only its
+/// own `<name>/` subdir — that mount is what stops one agent reaching
+/// another's socket. The literal lives in `hive-host-sock` (shared with
 /// `hivectl`); re-exported here under the name this module's consumers
 /// have always used.
 pub use hive_host_sock::AGENT_SOCKET_DIR;

hive-priv-sock/src/lib.rs

@@ -92,10 +92,9 @@ pub enum InfraContainer {
 /// What an [`InfraContainer`] resolves to on the host — i.e. the thing a
 /// lifecycle verb actually acts on.
 ///
-/// The gateway is why this exists: its nginx + dnsmasq were lifted out of
-/// an nspawn container and onto the host, so "restart the gateway" is a
-/// plain host unit now. The operator verb is unchanged; only its target
-/// moved. Everything else is still a container.
+/// The gateway is why this exists: its nginx + dnsmasq are host
+/// services, so "restart the gateway" means a plain host unit. Every
+/// other variant is a container.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum InfraTarget {
     /// An nspawn container, controlled via `container@<name>.service` and
@@ -433,17 +432,13 @@ pub enum PrivRequest {
     /// - otherwise → `systemctl start nginx`
     ///
     /// Requires root because hive-c0re runs as the unprivileged
-    /// `hive-core` user and cannot act on a system unit. It used to be
-    /// root for a *different* reason — `--machine=hive-gateway` entering
-    /// the container's namespace over the machine bus — and that reason
-    /// died with the container: nginx is a host unit now. The
-    /// requirement survived the move; its justification did not.
+    /// `hive-core` user and cannot act on a system unit.
     ///
     /// ⚠️ The unit name is **not** a parameter and must stay that way.
-    /// `--machine=` was doing double duty — transport *and* scope — so
-    /// dropping it removed the containment along with the namespace hop.
-    /// Hard-coding `nginx` is what replaces it: a caller cannot name the
-    /// unit, so this verb cannot be steered at any other service.
+    /// nginx is a host unit, so nothing else narrows what this verb can
+    /// touch: hard-coding `nginx` is the entire containment. A caller
+    /// cannot name the unit, so this verb cannot be steered at any other
+    /// service.
     ReloadGatewayNginx,
 
     // --- Forge admin CLI ---

hive-priv/src/main.rs

@@ -2186,11 +2186,9 @@ async fn read_container_journal(container: &str, query: &JournalQuery) -> Result
 /// - otherwise → `systemctl start nginx`
 ///
 /// ⚠️ `nginx` is hard-coded on purpose — see `PrivRequest::ReloadGatewayNginx`.
-/// The unit name is the scope of this verb, and it used to be enforced by
-/// `--machine=hive-gateway` (which could only reach into that container).
-/// With nginx on the host there is no namespace to bound it, so the
-/// literal is the only thing standing between "reload the gateway" and
-/// "reload anything".
+/// The unit name is the scope of this verb: nginx is a host unit, so no
+/// namespace bounds it and the literal is the only thing standing between
+/// "reload the gateway" and "reload anything".
 ///
 /// Returns `(String::new(), String::new())` on success so it fits the
 /// `exec` return type directly.

nix/host-modules/hive-gateway/default.nix

@@ -1,10 +1,9 @@
 # Single nginx in front of every hyperhive web surface — dashboard,
 # per-agent UIs (sub-path), forge + matrix (sub-domain), .well-known
 # delegations — plus the hive-internal dnsmasq resolver. Both run on the
-# HOST, next to hive-c0re. They used to live in a `hive-gateway`
-# container that shared the host netns anyway, so the boundary bought no
-# network isolation and cost a resolv.conf sync, a reload that had to
-# cross the machine bus, and four bind mounts.
+# HOST, next to hive-c0re: nginx binds the host's :80/:443 and dnsmasq
+# answers on the hive bridge, so neither can be confined to a network
+# namespace of its own.
 # Full vhost map + discovery flow + design rationale in
 # `docs/gateway.md`. Layout: ./options.nix (option declarations),
 # ./vhosts.nix (the nginx virtual-host tree), ./error-pages.nix
@@ -106,11 +105,9 @@ in
     ];
 
     # Ensure the gateway state dirs exist at host boot, before anything
-    # reads or writes them. They used to double as bind-mount sources
-    # for the container (nspawn would auto-create a missing one); the
-    # rules stay because they still cover the fresh-boot window before
-    # c0re has run, and they pin owner + mode rather than leaving it to
-    # whoever creates the path first.
+    # reads or writes them: these rules cover the fresh-boot window
+    # before c0re has run, and pin owner + mode rather than leaving it
+    # to whoever creates the path first.
     #
     # /run/hive-agent — per-agent UDS socket dir, written by c0re's
     # set_nspawn_flags when agents start. Owned by `hive-core` (the
@@ -273,11 +270,8 @@ in
     # unprivileged and cannot act on a system unit).
     #
     # It stays an explicit trigger rather than a systemd path unit
-    # watching the file. That used to be impossible — an IN_MOVED_TO
-    # from the atomic rename did not cross the nspawn mount-namespace
-    # boundary — and with one machine it would now work. It is still
-    # not wanted: the write and the reload belong in one causal chain
-    # c0re can retry and report on (see RELOAD_PENDING), not two
+    # watching the file: the write and the reload belong in one causal
+    # chain c0re can retry and report on (see RELOAD_PENDING), not two
     # independent units racing on an inotify event.
 
     services.nginx = {
@@ -289,10 +283,9 @@ in
       inherit (nginxTree) appendHttpConfig virtualHosts;
     };
 
-    # dnsmasq moves with nginx rather than staying behind: it was only in
-    # the container because nginx was, and leaving it there would keep the
-    # whole resolv.conf sync machine alive for a resolver that no longer
-    # needs it. Host-side it reads the one /etc/resolv.conf directly.
+    # dnsmasq is a host service alongside nginx, so it reads the host's
+    # /etc/resolv.conf directly and picks up network changes as they
+    # happen — no copy to keep in sync.
     services.dnsmasq = import ./dnsmasq.nix {
       inherit
         lib

swarm-controller/README.md

@@ -42,11 +42,9 @@ What keeps that safe is that the directory holds **one** socket. So:
 > Pointing nginx at that directory to reach this socket would put the admin
 > socket within its reach too.
 
-This got *less* forgiving when nginx moved onto the host: the gateway used to
-reach a unix upstream through a bind-mount, so the mount list was a second
-bound on what it could touch. There is no mount now — the directory is the
-whole of the access control. A unit test pins the default path so a tidying
-edit fails instead of reviewing cleanly.
+nginx is a host service, so nothing narrows what it can reach except the
+directory itself — that is the whole of the access control. A unit test pins
+the default path so a tidying edit fails instead of reviewing cleanly.
 
 `RuntimeDirectoryPreserve=yes` and the daemon's stale-socket unlink on start are
 a **pair**: preserving the directory without the unlink means `bind` fails with

swarm-controller/src/main.rs

@@ -29,10 +29,8 @@ use axum::{Router, routing::get};
 /// The directory is its own — deliberately not shared with hive-c0re's
 /// `/run/hyperhive`. The socket is `0666`, so its directory is the only
 /// access control it has; co-locating it with c0re's admin socket would
-/// put both within reach of whatever can reach either. That used to be
-/// enforced by which *directory* was bind-mounted into the gateway
-/// container; with nginx on the host the mount is gone and the directory
-/// is all that is left, so the rule matters more, not less.
+/// put both within reach of whatever can reach either. nginx runs on the
+/// host, so nothing narrows its reach for you.
 const DEFAULT_SOCKET: &str = "/run/swarm-controller/controller.sock";
 
 fn socket_path() -> PathBuf {
@@ -98,9 +96,8 @@ mod tests {
     /// The socket must not share a directory with anything else, because
     /// the socket is `0666` and the directory is therefore the only access
     /// control it has. `/run/hyperhive` in particular holds hive-c0re's
-    /// **admin** socket. nginx used to reach a unix upstream by mounting
-    /// the socket's whole directory into the gateway container; it runs on
-    /// the host now, so nothing narrows its reach but the directory itself.
+    /// **admin** socket, and nginx — a host service — is bounded by
+    /// nothing but the directory itself.
     ///
     /// A test rather than a comment: the failure this guards against is a
     /// one-word edit that looks tidier and reads fine in review.