# 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 = '' 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 nixos/tests/common/letsencrypt 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]+(${reHost})(.*)" str; continue = lib.singleton (lib.head matched) ++ matchAliases (lib.last matched); in if matched == null then [] else continue; matchLine = str: let result = builtins.match "[ \t]*(${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} ''; }; }; }