nixpkgs/nixos/tests/common/resolver.nix
2023-07-12 09:36:28 +01:00

142 lines
5.5 KiB
Nix

# This module automatically discovers zones in BIND and NSD NixOS
# configurations and creates zones for all definitions of networking.extraHosts
# (except those that point to 127.0.0.1 or ::1) within the current test network
# and delegates these zones using a fake root zone served by a BIND recursive
# name server.
{ config, nodes, pkgs, lib, ... }:
{
options.test-support.resolver.enable = lib.mkOption {
type = lib.types.bool;
default = true;
internal = true;
description = lib.mdDoc ''
Whether to enable the resolver that automatically discovers zone in the
test network.
This option is `true` by default, because the module
defining this option needs to be explicitly imported.
The reason this option exists is for the
{file}`nixos/tests/common/acme/server` module, which
needs that option to disable the resolver once the user has set its own
resolver.
'';
};
config = lib.mkIf config.test-support.resolver.enable {
networking.firewall.enable = false;
services.bind.enable = true;
services.bind.cacheNetworks = lib.mkForce [ "any" ];
services.bind.forwarders = lib.mkForce [];
services.bind.zones = lib.singleton {
name = ".";
file = let
addDot = zone: zone + lib.optionalString (!lib.hasSuffix "." zone) ".";
mkNsdZoneNames = zones: map addDot (lib.attrNames zones);
mkBindZoneNames = zones: map (zone: addDot zone.name) zones;
getZones = cfg: mkNsdZoneNames cfg.services.nsd.zones
++ mkBindZoneNames cfg.services.bind.zones;
getZonesForNode = attrs: {
ip = attrs.config.networking.primaryIPAddress;
zones = lib.filter (zone: zone != ".") (getZones attrs.config);
};
zoneInfo = lib.mapAttrsToList (lib.const getZonesForNode) nodes;
# A and AAAA resource records for all the definitions of
# networking.extraHosts except those for 127.0.0.1 or ::1.
#
# The result is an attribute set with keys being the host name and the
# values are either { ipv4 = ADDR; } or { ipv6 = ADDR; } where ADDR is
# the IP address for the corresponding key.
recordsFromExtraHosts = let
getHostsForNode = lib.const (n: n.config.networking.extraHosts);
allHostsList = lib.mapAttrsToList getHostsForNode nodes;
allHosts = lib.concatStringsSep "\n" allHostsList;
reIp = "[a-fA-F0-9.:]+";
reHost = "[a-zA-Z0-9.-]+";
matchAliases = str: let
matched = builtins.match "[ \t]+(${reHost})(.*)" str;
continue = lib.singleton (lib.head matched)
++ matchAliases (lib.last matched);
in lib.optional (matched != null) continue;
matchLine = str: let
result = builtins.match "[ \t]*(${reIp})[ \t]+(${reHost})(.*)" str;
in if result == null then null else {
ipAddr = lib.head result;
hosts = lib.singleton (lib.elemAt result 1)
++ matchAliases (lib.last result);
};
skipLine = str: let
rest = builtins.match "[^\n]*\n(.*)" str;
in if rest == null then "" else lib.head rest;
getEntries = str: acc: let
result = matchLine str;
next = getEntries (skipLine str);
newEntry = acc ++ lib.singleton result;
continue = if result == null then next acc else next newEntry;
in if str == "" then acc else continue;
isIPv6 = str: builtins.match ".*:.*" str != null;
loopbackIps = [ "127.0.0.1" "::1" ];
filterLoopback = lib.filter (e: !lib.elem e.ipAddr loopbackIps);
allEntries = lib.concatMap (entry: map (host: {
inherit host;
${if isIPv6 entry.ipAddr then "ipv6" else "ipv4"} = entry.ipAddr;
}) entry.hosts) (filterLoopback (getEntries (allHosts + "\n") []));
mkRecords = entry: let
records = lib.optional (entry ? ipv6) "AAAA ${entry.ipv6}"
++ lib.optional (entry ? ipv4) "A ${entry.ipv4}";
mkRecord = typeAndData: "${entry.host}. IN ${typeAndData}";
in lib.concatMapStringsSep "\n" mkRecord records;
in lib.concatMapStringsSep "\n" mkRecords allEntries;
# All of the zones that are subdomains of existing zones.
# For example if there is only "example.com" the following zones would
# be 'subZones':
#
# * foo.example.com.
# * bar.example.com.
#
# While the following would *not* be 'subZones':
#
# * example.com.
# * com.
#
subZones = let
allZones = lib.concatMap (zi: zi.zones) zoneInfo;
isSubZoneOf = z1: z2: lib.hasSuffix z2 z1 && z1 != z2;
in lib.filter (z: lib.any (isSubZoneOf z) allZones) allZones;
# All the zones without 'subZones'.
filteredZoneInfo = map (zi: zi // {
zones = lib.filter (x: !lib.elem x subZones) zi.zones;
}) zoneInfo;
in pkgs.writeText "fake-root.zone" ''
$TTL 3600
. IN SOA ns.fakedns. admin.fakedns. ( 1 3h 1h 1w 1d )
ns.fakedns. IN A ${config.networking.primaryIPAddress}
. IN NS ns.fakedns.
${lib.concatImapStrings (num: { ip, zones }: ''
ns${toString num}.fakedns. IN A ${ip}
${lib.concatMapStrings (zone: ''
${zone} IN NS ns${toString num}.fakedns.
'') zones}
'') (lib.filter (zi: zi.zones != []) filteredZoneInfo)}
${recordsFromExtraHosts}
'';
};
};
}