# hive-network Host-side bridge + per-agent private-netns isolation — always on whenever hyperhive is enabled. Configured via `services.hyperhive.network.*`. > Isolation is the only mode — there is no shared-netns fallback. The > former `services.hyperhive.network.enable`, > `services.hyperhive.network.isolateContainers` and > `services.hyperhive.network.upstreamDns` options were removed; a > config that still sets one fails eval with a removal message. ## Network map One picture of the whole hive. There are two planes: **infra containers share the host netns** and bind host ports directly; **compute containers (agents + CI) each get a private netns** behind the bridge. The unix-socket control plane rides the VFS and is untouched by any of it. ``` internet │ uplink NIC — NAT MASQUERADE for the │ bridge subnet (10.42.0.0/24 default) ┌──────────────────────────┴─────────────────────────────────────────┐ │ host netns — the host itself plus gateway / forge / matrix │ │ │ │ nginx :80/:443 [hive-gateway] │ │ dnsmasq 10.42.0.1:53 (DNS) + :67 (DHCP) [hive-gateway] │ │ forgejo :3000 http, :2222 git-ssh [hive-forge] │ │ tuwunel :8008 client API [hive-matrix] │ │ hive-c0re dashboard 127.0.0.1:7000 (host service) │ │ wg-hive :51820/udp — swarm mesh, when enabled (host iface) │ │ │ │ hive-br0 10.42.0.1/24 │ │ ┌──────────┼──────────────┐ │ └──────────────┼──────────┼──────────────┼───────────────────────────┘ vb-h- vb-h- vb-hive-ci veth pairs │ │ │ ┌────┴────┐ ┌───┴─────┐ ┌──────┴──┐ one private netns │ agent a │ │ agent b │ │ hive-ci │ each; eth0 leases │ eth0 │ │ eth0 │ │ eth0 │ from the DHCP pool └─────────┘ └─────────┘ └─────────┘ ``` | container | netns | IPv4 | listens / reached via | | -------------- | ----------------------- | -------------------- | -------------------------------------------------------------------------------------------- | | `hive-gateway` | host (shared) | host addresses | nginx `:80`/`:443` (every vhost); dnsmasq `bridgeIp:53` + DHCP `:67` on the bridge | | `hive-forge` | host (shared) | host addresses | forgejo `:3000` http, `:2222` git-ssh; fronted by the `forge.` vhost | | `hive-matrix` | host (shared) | host addresses | tuwunel `:8008` (+ optional federation port); fronted by the matrix vhost | | `hive-ci` | private, veth on bridge | DHCP pool | outbound only (runner → forge); no inbound surface | | `h-` | private, veth on bridge | DHCP pool | web UI via UDS `/run/hive-agent/` → nginx sub-path; in-container UI port hashed 8100–8999 | The flows, end to end: - **DHCP** — agent `dhcpcd` broadcasts on `eth0` → veth → bridge → host firewall (udp 67 hole) → dnsmasq pool → lease + router option. - **DNS** — agents query `bridgeIp:53`; hive zones are answered authoritatively with the bridge IP, everything else forwards to the host's resolvers (see *Resolver behaviour* below). - **HTTP** — `forge.` and `chat.` (under `swarm.domain`) plus the hive's own dashboard name resolve to the bridge IP, land on nginx `:80`/`:443`, and proxy to forgejo `:3000`, tuwunel `:8008`, hive-c0re `127.0.0.1:7000`, or a per-agent UI unix socket. - **Internet egress** — agent default route points at the bridge IP; the host forwards + masquerades out its uplink. - **Swarm** — peer hives connect over the `wg-hive` WireGuard mesh and reach each other's gateway/forge across it ([`docs/swarm/`](swarm/README.md)). - **Control plane (no network)** — per-agent broker socket `/run/hive/mcp.sock`, privileged helper `/run/hive/priv.sock`, operator admin `/run/hyperhive/host.sock`, and the per-agent UI sockets under `/run/hive-agent/` are unix domain sockets bind-mounted through the VFS; private netns does not affect them. ## Container shape (where dnsmasq lives) Co-located in the existing `hive-gateway` container — single front-door for both DNS and HTTP, saves a sibling container, single systemd-unit / state surface to monitor. The gateway shares host netns (`privateNetwork = false`) so dnsmasq's `bind-interfaces` listener on `bridgeIp` is on the host's bridge interface. ## Configuration ```nix { services.hyperhive = { enable = true; hiveName = "pr1ma"; swarm.domain = "darkest.space"; swarm.hives.pr1ma = { }; # -> domain = pr1ma.darkest.space # network.bridgeIp = "10.42.0.1"; # default }; } ``` Requires `services.hyperhive.domain` to be set — the dnsmasq resolver is authoritative for `` and its sub-domains. You do not write it: it is read from this hive's entry in the swarm directory (`docs/swarm/README.md` § Hive identity config). ## Bridge addressing Default subnet is `10.42.0.0/24`, host-side gateway at `10.42.0.1`. RFC 1918 space, unlikely to clash with operator's existing setup; override `bridgeIp` + `bridgePrefixLength` if a different range is already in use. `/24` gives 254 usable per-agent addresses — enough for any single-host hive; bigger swarms or tighter addressing schemes pick their own. ## Resolver behaviour dnsmasq is **authoritative** for the hive's own zone (``) plus whatever swarm-service names this host contributes via `gateway.localNames` — `forge.` and `chat.` (matrix) when this host runs those services, and `auth.` when it runs authelia — answering each with the bridge IP (where nginx is reachable). Note forge and matrix are swarm-domain names, not sub-domains of ``: a swarm runs one forge and one homeserver, so their names belong to the swarm rather than to whichever hive happens to host them. Everything else is forwarded to the host's own resolvers: dnsmasq runs on the host and reads the host's `/etc/resolv.conf` directly. Containers don't need to know the upstream — they query the bridge IP and dnsmasq does the right thing per-name. 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. 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 container health-checks). External hosts can't reach it — no DNS-amplification surface even when the operator opens port 80 for gateway HTTP. `resolveLocalQueries = false` keeps dnsmasq out of the host's own resolution stack — the host's resolver (systemd-resolved, plain glibc nss, dnscrypt-proxy, etc.) keeps doing whatever the operator configured. The hive resolver is purely for inbound queries from agent containers. ## Firewall posture `networking.firewall.interfaces..allowedUDPPorts = [ 53 67 ]` `networking.firewall.interfaces..allowedTCPPorts = [ 53 80 443 ]` - Port 53 opens the resolver on the bridge interface only. Other interfaces stay closed. The hive resolver isn't an external-facing service. - Port 67 (UDP) admits DHCP requests to the dnsmasq pool. dnsmasq receives DHCP via a regular UDP socket (it does not use a netfilter-bypassing raw socket), so the hole is mandatory — without it containers never get a lease and fall back to 169.254.x.x. - Ports 80 and 443 let isolated agents reach nginx (gateway container, shared host netns) for the forge sub-domain, per-agent UI proxies, and any other HTTP services. The **host** firewall is the only firewall. The shared-netns infra containers (gateway, forge, matrix) set `networking.firewall.enable = false`: a NixOS firewall inside a shared-netns container runs against the *host* ruleset — at container boot its `firewall-start` flushes the `nixos-fw` chains, rebuilds them from the container's (empty) port list, and deletes the host's `nixos-nat-*` chains without recreating them, silently wiping the bridge holes above plus the agents' NAT. Private-netns containers (agents, hive-ci) may keep their own firewall — it is scoped to their namespace. ### Reaching host services (`exposeHostPorts`) By default agents can only reach the host on 80/443 (+53 DNS), so a host-side service on another port — e.g. a dev OTLP collector you want agents to reach directly — is unreachable. (hyperhive's own telemetry needs none of this: `otel.enable` opens its collector's port itself, and `otel.endpoint` is the *upstream*, which no agent ever dials. See `docs/observability.md`.) `services.hyperhive.network.exposeHostPorts = [ 4318 ];` opens each listed TCP port `P` on the bridge-interface `allowedTCPPorts`, so an agent can connect to `:P` (point the collector endpoint at `http://:4318`, default `http://10.42.0.1:4318`). This is **firewall-only**: the host service must bind an address reachable from the bridge — `0.0.0.0` or the bridge IP — not loopback only. The bridge→`127.0.0.0/8` DROP rule (below) is unchanged, so a service bound to `127.0.0.1` only stays unreachable; rebind it to `0.0.0.0`. The port is reachable by **every** agent on the bridge subnet (like DNS/gateway), so only expose services safe for any agent to reach. ## Container isolation Each agent container runs in a private network namespace with a dedicated veth pair attached to the bridge. The following table summarises what the nix side sets up unconditionally: | effect | mechanism | | -------------- | ------------------------------------------------------------------------------------------------------------------------------------- | | IP forwarding | `boot.kernel.sysctl."net.ipv4.ip_forward" = 1` | | Internet NAT | `networking.nat { enable = true; internalInterfaces = [ bridgeName ]; }` — MASQUERADE on packets leaving via any external NIC | | Loopback DROP | `networking.firewall.extraInputRules` — drops bridge-subnet → `127.0.0.0/8` traffic; defence-in-depth against routing table leaks | | Gateway access | `networking.firewall.interfaces..allowedTCPPorts = [ 80 443 ]` — lets isolated agents (private netns, veth on bridge) reach nginx on the host | | c0re signal | `HIVE_NETWORK_ISOLATION=1`, `HIVE_NETWORK_BRIDGE`, `HIVE_NETWORK_SUBNET` in `systemd.services.hive-c0re.environment` | `HIVE_NETWORK_SUBNET` is the host-side bridge IP + prefix (e.g. `10.42.0.1/24`), **not** the canonical network address. The Rust side must normalise (bitwise-AND with mask) before subnet membership checks or address arithmetic. ### What the Rust side does `hive-c0re` reads `HIVE_NETWORK_ISOLATION` and passes `PRIVATE_NETWORK=1`, `LOCAL_ADDRESS=` (empty), `HOST_ADDRESS=`, and `HOST_BRIDGE=` via `lifecycle::set_nspawn_flags` when creating or updating containers. `LOCAL_ADDRESS` is left empty so the container's dhcpcd acquires an address from the bridge dnsmasq pool (`networking.useDHCP = true` in `nix/agent-modules/network.nix`). This applies uniformly to all containers — agents and service containers alike. `HOST_ADDRESS` is the bridge gateway IP (the address part of `HIVE_NETWORK_SUBNET`, via `lifecycle::bridge_gateway_ip` — taken verbatim so a non-`.1` operator override still resolves to wherever the bridge actually lives). It is **load-bearing**: nixos-container's container-side network setup only installs a default route (`ip route add default via $HOST_ADDRESS`) when `HOST_ADDRESS` is non-empty. In bridge mode the host-side address/route setup is skipped, so writing it only affects the container's default route — without it the container comes up with an IP but no path off the bridge subnet (no internet, no `api.anthropic.com`). ### How the isolated container gets its resolver nixos-container copies the **host's** `/etc/resolv.conf` into the container at every start. The host resolver (e.g. `127.0.0.53` from systemd-resolved, or a LAN router) is unreachable from a private netns and isn't authoritative for the hive's own zones, so it is replaced with the bridge dnsmasq at boot. Because the copy happens on every start, a declarative `environment.etc."resolv.conf"` would be clobbered — so the wiring is runtime: - `hive-priv` drops a marker file (`/etc/hyperhive-bridge-dns`, carrying the gateway IP) into each container's `/etc`. - the `hyperhive-isolated-dns` oneshot (`nix/agent-modules/network.nix`), gated on that marker, rewrites `/etc/resolv.conf` to `nameserver ` at boot. It is ordered `before` the harness (`hive-ag3nt`), the matrix daemon, and `tea-login` so the resolver is correct before the first DNS lookup. **Why isolation is safe**: hive-c0re's control-plane sockets are unix domain sockets bind-mounted into containers, not network listeners — see the *Control plane (no network)* bullet under [Network map](#network-map) above. `PRIVATE_NETWORK=1` has no effect on a path that never touches the network stack. The nix side also enables IP forwarding + NAT (agents reach the internet through the host) and drops bridge-subnet → loopback traffic (defence-in-depth against a compromised agent reaching the c0re dashboard HTTP at `127.0.0.1`). Agents have no legitimate reason to reach the dashboard over loopback — the hive-c0re admin socket is a UDS, not TCP. ## Cross-references - `docs/gateway.md` — vhost map + the gateway's other duties