liminix/modules/dnsmasq/default.nix

## Dnsmasq
## =======
##
## This module includes a service to provide DNS, DHCP, and IPv6
## router advertisement for the local network.

{
  lib,
  pkgs,
  config,
  ...
}:
let
  inherit (lib) mkOption types;
  inherit (pkgs) liminix;
in
{
  options = {
    system.service.dnsmasq = mkOption {
      type = liminix.lib.types.serviceDefn;
    };
  };
  config = {
    system.service.dnsmasq = config.system.callService ./service.nix {
      user = mkOption {
        type = types.str;
        default = "dnsmasq";
        description = "Specifies the unix user which dnsmasq will run as";
      };
      group = mkOption {
        type = types.str;
        default = "dnsmasq";
        description = "Specifies the unix group which dnsmasq will run as";
      };
      resolvconf = mkOption {
        type = types.nullOr liminix.lib.types.service;
        default = null;
      };
      interface = mkOption {
        type = liminix.lib.types.service;
        default = null;
      };
      upstreams = mkOption {
        type = types.listOf types.str;
        default = [ ];
      };
      ranges = mkOption {
        type = types.listOf types.str;
      };
      hosts = mkOption {
        default = { };
        type = types.attrsOf (
          types.submodule {
            options = {
              mac = mkOption {
                description = ''
                  MAC or other hardware address to match on. For Ethernet
                  this is a 48 bit address represented as colon-separated
                  hex bytes, or "id:clientid" to match a presented
                  client id (IPv6 DUID)
                '';
                type = types.str;
                example = "01:20:31:4a:50";
              };
              v4 = mkOption {
                description = "IPv4 address to assign to this client";
                example = "192.0.2.1";
                type = types.str;
              };
              v6 = mkOption {
                type = types.listOf types.str;
                description = "IPv6 addresses or interface-ids to assign to this client";
                default = [ ];
                example = [
                  "fe80::42:1eff:fefd:b341"
                  "::1234"
                ];
              };
              leasetime = mkOption {
                type = types.int;
                default = 86400;
              };
            };
          }
        );
      };
      domain = mkOption {
        # this can be given multiple times so probably should be
        # domains plural and list of string
        description = "Domain name for DHCP service: causes the DHCP server to return the domain to any hosts which request it, and sets the domain which it is legal for DHCP-configured hosts to claim";
        type = types.str;
        example = "example.com";
      };
    };
    users.dnsmasq = {
      uid = 51;
      gid = 51;
      gecos = "DNS/DHCP service user";
      dir = "/run/dnsmasq";
      shell = "/bin/false";
    };
    groups.dnsmasq = {
      gid = 51;
      usernames = [ "dnsmasq" ];
    };
    groups.system.usernames = [ "dnsmasq" ];
  };
}