hyperhive/nix/host-modules/hive-gateway/dnsmasq.nix

61 lines
2.6 KiB
Nix

# Hive-internal DNS resolver + DHCP, co-located in the gateway
# container — single front-door for both DNS and HTTP, saves a
# sibling container. Listens on the bridge interface from
# `services.hyperhive.network`; authoritative for the hive domain +
# sub-domains, forwards everything else upstream. Returns the
# `services.dnsmasq` value for the container config (see
# ./default.nix); the DHCP pool bounds are computed by hive-network.
{
lib,
networkCfg,
forgeCfg,
matrixCfg,
hyperhiveDomain,
}:
{
enable = true;
# Don't substitute the container's /etc/resolv.conf — the gateway
# uses the host's resolver for its own outbound traffic; dnsmasq is
# purely for incoming queries from agent containers.
resolveLocalQueries = false;
settings = {
# Bind only on the bridge interface (and lo for health-checks).
# Outside hosts can't even see the listener.
interface = [
networkCfg.bridgeName
"lo"
];
bind-interfaces = true;
port = 53;
# Hive authoritative records — answer queries for the hive domain
# + its sub-domains with the bridge IP, where nginx is reachable
# from every container netns.
#
# The forge / matrix entries are redundant in the common case
# where `forge.domain` / `matrix.gatewayHost` are sub-domains of
# `hyperhive.domain` — dnsmasq's `/<domain>/` rule already matches
# sub-domains. Kept explicit because operators can override either
# to a cross-domain hostname (e.g. `forge.domain =
# "git.example.com"`); listing them explicitly keeps that case
# routed without needing an extra config block.
address = [
"/${hyperhiveDomain}/${networkCfg.bridgeIp}"
]
++ lib.optional ((forgeCfg.behindGateway or false)) "/${forgeCfg.domain}/${networkCfg.bridgeIp}"
++ lib.optional (
matrixCfg.enable && matrixCfg.gatewayHost != null
) "/${matrixCfg.gatewayHost}/${networkCfg.bridgeIp}";
# DHCP pool covering all usable host addresses on the bridge
# subnet — bounds computed by hive-network.nix from
# bridgeIp/bridgePrefixLength. All containers (agents and service
# containers such as hive-ci) receive their IPs dynamically.
dhcp-range = "${networkCfg.dhcpRangeStart},${networkCfg.dhcpRangeEnd},1h";
dhcp-leasefile = "/var/lib/dnsmasq/dnsmasq.leases";
# No explicit upstream: non-hive queries follow dnsmasq's
# resolv.conf default — the gateway container's `/etc/resolv.conf`,
# which nixos-container copies from the host at every start, so the
# hive always uses the host's resolvers. resolvconf is disabled in
# the container (see ./default.nix) so nothing regenerates that
# copy.
};
}