import from nix-scripts

2020-06-20 17:54:21 +08:00 · 2020-06-20 17:54:21 +08:00 · 5a0afc48d4
commit 5a0afc48d4
40 changed files with 2978 additions and 0 deletions
--- a/nixbld-etc-nixos/backup-module.nix
+++ b/nixbld-etc-nixos/backup-module.nix
@ -0,0 +1,54 @@
+{ config, pkgs, lib, ... }:
+with lib;
+let
+  makeBackup = pkgs.writeScript "make-backup" ''
+    #!${pkgs.bash}/bin/bash
+
+    set -e
+    umask 0077
+
+    DBDUMPDIR=`mktemp -d`
+    pushd $DBDUMPDIR
+
+    ${config.services.mysql.package}/bin/mysqldump --single-transaction flarum > flarum.sql
+    ${pkgs.sudo}/bin/sudo -u mattermost ${config.services.postgresql.package}/bin/pg_dump mattermost > mattermost.sql
+
+    ${pkgs.gnutar}/bin/tar cf - --exclude "/var/lib/gitea/repositories/*/*.git/archives" /etc/nixos /var/lib/gitea flarum.sql mattermost.sql | \
+        ${pkgs.bzip2}/bin/bzip2 | \
+        ${pkgs.gnupg}/bin/gpg --symmetric --batch --passphrase-file /etc/nixos/secret/backup-passphrase | \
+        ${pkgs.rclone}/bin/rclone rcat --config /etc/nixos/secret/rclone.conf dropbox:backup-`date +%F`.tar.bz2.gpg
+
+    popd
+    rm -rf $DBDUMPDIR
+
+    echo Backup done
+  '';
+  cfg = config.services.mlabs-backup;
+in
+{
+  options.services.mlabs-backup = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable backups";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.mlabs-backup = {
+      description = "M-Labs backup";
+      serviceConfig = {
+        Type = "oneshot";
+        User = "root";
+        Group = "root";
+        ExecStart = "${makeBackup}";
+      };
+    };
+
+    systemd.timers.mlabs-backup = {
+      description = "M-Labs backup";
+      wantedBy = [ "timers.target" ];
+      timerConfig.OnCalendar = "weekly";
+    };
+  };
+}
--- a/nixbld-etc-nixos/configuration.nix
+++ b/nixbld-etc-nixos/configuration.nix
@ -0,0 +1,667 @@
+# Edit this configuration file to define what should be installed on
+# your system.  Help is available in the configuration.nix(5) man page
+# and in the NixOS manual (accessible by running ‘nixos-help’).
+
+{ config, pkgs, ... }:
+
+let
+  netifWan = "enp0s31f6";
+  netifLan = "enp3s0";
+  netifWifi = "wlp1s0";
+  netifSit = "henet0";
+  hydraWwwOutputs = "/var/www/hydra-outputs";
+in
+{
+  imports =
+    [
+      ./hardware-configuration.nix
+      ./homu/nixos-module.nix
+      ./backup-module.nix
+      (builtins.fetchTarball {
+        url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/v2.3.0/nixos-mailserver-v2.3.0.tar.gz";
+        sha256 = "0lpz08qviccvpfws2nm83n7m2r8add2wvfg9bljx9yxx8107r919";
+      })
+    ];
+
+  # Use the systemd-boot EFI boot loader.
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+  boot.blacklistedKernelModules = ["iwlwifi"];
+
+  security.apparmor.enable = true;
+
+  networking = {
+    hostName = "nixbld";
+    firewall = {
+      allowedTCPPorts = [ 80 443 ];
+      allowedUDPPorts = [ 53 67 ];
+      trustedInterfaces = [ netifLan ];
+    };
+    interfaces."${netifLan}" = {
+      ipv4.addresses = [{
+        address = "192.168.1.1";
+        prefixLength = 24;
+      }];
+      ipv6.addresses = [{
+        address = "2001:470:f821:1::";
+        prefixLength = 64;
+      }];
+    };
+    interfaces."${netifWifi}" = {
+      ipv4.addresses = [{
+        address = "192.168.12.1";
+        prefixLength = 24;
+      }];
+      ipv6.addresses = [{
+        address = "2001:470:f821:2::";
+        prefixLength = 64;
+      }];
+    };
+    nat = {
+      enable = true;
+      externalInterface = netifWan;
+      internalInterfaces = [ netifLan netifWifi ];
+      forwardPorts = [
+        { sourcePort = 2201; destination = "192.168.1.201:22"; proto = "tcp"; }
+        { sourcePort = 2202; destination = "192.168.1.202:22"; proto = "tcp"; }
+        { sourcePort = 2203; destination = "192.168.1.203:22"; proto = "tcp"; }
+        { sourcePort = 2204; destination = "192.168.1.204:22"; proto = "tcp"; }
+        { sourcePort = 2205; destination = "192.168.1.205:22"; proto = "tcp"; }
+      ];
+      extraCommands = ''
+        iptables -w -N block-lan-from-wifi
+        iptables -w -A block-lan-from-wifi -i ${netifLan} -o ${netifWifi} -j DROP
+        iptables -w -A block-lan-from-wifi -i ${netifWifi} -o ${netifLan} -j DROP
+        iptables -w -A FORWARD -j block-lan-from-wifi
+      '';
+      extraStopCommands = ''
+        iptables -w -D FORWARD -j block-lan-from-wifi 2>/dev/null|| true
+        iptables -w -F block-lan-from-wifi 2>/dev/null|| true
+        iptables -w -X block-lan-from-wifi 2>/dev/null|| true
+      '';
+    };
+    sits."${netifSit}" = {
+      dev = netifWan;
+      remote = "216.218.221.6";
+      local = "42.200.147.171";
+      ttl = 255;
+    };
+    interfaces."${netifSit}".ipv6 = {
+      addresses = [{ address = "2001:470:18:629::2"; prefixLength = 64; }];
+      routes = [{ address = "::"; prefixLength = 0; }];
+    };
+  };
+  boot.kernel.sysctl."net.ipv6.conf.all.forwarding" = "1";
+  boot.kernel.sysctl."net.ipv6.conf.default.forwarding" = "1";
+
+  services.unbound = {
+    enable = true;
+    extraConfig =
+    ''
+    server:
+      port: 5353
+    '';
+  };
+
+  services.hostapd = {
+    enable        = true;
+    interface     = netifWifi;
+    hwMode        = "g";
+    ssid          = "M-Labs";
+    wpaPassphrase = (import /etc/nixos/secret/wifi_password.nix);
+    extraConfig   = ''
+      ieee80211d=1
+      country_code=HK
+      ieee80211n=1
+      wmm_enabled=1
+      auth_algs=1
+      wpa_key_mgmt=WPA-PSK
+      rsn_pairwise=CCMP
+    '';
+  };
+  services.dnsmasq = {
+    enable = true;
+    servers = ["::1#5353"];
+    extraConfig = ''
+      interface=${netifLan}
+      interface=${netifWifi}
+      bind-interfaces
+      dhcp-range=interface:${netifLan},192.168.1.81,192.168.1.254,24h
+      dhcp-range=interface:${netifWifi},192.168.12.10,192.168.12.254,24h
+      enable-ra
+      dhcp-range=interface:${netifLan},::,constructor:${netifLan},ra-names
+      dhcp-range=interface:${netifWifi},::,constructor:${netifWifi},ra-only
+
+      no-resolv
+
+      # Static IPv4s to make Red Pitayas less annoying
+      dhcp-host=rp-f05cc9,192.168.1.190
+      dhcp-host=rp-f0612e,192.168.1.191
+      # Static IPv4s to make port redirections work
+      dhcp-host=rpi-1,192.168.1.201
+      dhcp-host=rpi-2,192.168.1.202
+      dhcp-host=rpi-3,192.168.1.203
+      dhcp-host=rpi-4,192.168.1.204
+      dhcp-host=rpi-5,192.168.1.205
+
+      # Default IP addresses for ARTIQ boards
+      address=/thermostat/192.168.1.26
+      address=/kc705/192.168.1.50
+      address=/zc706/192.168.1.51
+      address=/zc706-2/192.168.1.52
+      address=/sayma/192.168.1.60
+      address=/metlino/192.168.1.65
+      address=/kasli/192.168.1.70
+      address=/kasli-customer/192.168.1.75
+      address=/stabilizer-customer/192.168.1.76
+      # uTCA MCH from NAT
+      address=/tschernobyl/192.168.1.80
+    '';
+  };
+
+  # Select internationalisation properties.
+  i18n.defaultLocale = "en_US.UTF-8";
+  console = {
+    font = "Lat2-Terminus16";
+    keyMap = "de";
+  };
+
+  # Set your time zone.
+  time.timeZone = "Asia/Hong_Kong";
+
+  # List packages installed in system profile. To search, run:
+  # $ nix search wget
+  environment.systemPackages = with pkgs; [
+    wget vim git file lm_sensors acpi pciutils psmisc telnet nixops
+    irssi tmux usbutils imagemagick jq zip unzip
+  ];
+
+  # Some programs need SUID wrappers, can be configured further or are
+  # started in user sessions.
+  # programs.mtr.enable = true;
+  # programs.gnupg.agent = { enable = true; enableSSHSupport = true; };
+
+  # List services that you want to enable:
+
+  services.apcupsd.enable = true;
+  services.apcupsd.configText = ''
+    UPSTYPE usb
+    NISIP 127.0.0.1
+    BATTERYLEVEL 10
+    MINUTES 5
+  '';
+
+  # Enable the OpenSSH daemon.
+  services.openssh.enable = true;
+  services.openssh.forwardX11 = true;
+  services.openssh.passwordAuthentication = false;
+  programs.mosh.enable = true;
+
+  programs.fish.enable = true;
+
+  # Enable CUPS to print documents.
+  services.avahi.enable = true;
+  services.avahi.interfaces = [ netifLan ];
+  services.avahi.publish.enable = true;
+  services.avahi.publish.userServices = true;
+  nixpkgs.config.allowUnfree = true;
+  services.printing.enable = true;
+  services.printing.drivers = [ pkgs.hplipWithPlugin ];
+  services.printing.browsing = true;
+  services.printing.listenAddresses = [ "*:631" ];
+  services.printing.defaultShared = true;
+  hardware.sane.enable = true;
+  hardware.sane.extraBackends = [ pkgs.hplipWithPlugin ];
+
+  users.extraGroups.plugdev = { };
+  users.extraUsers.sb = {
+    isNormalUser = true;
+    extraGroups = ["wheel" "plugdev" "dialout" "lp" "scanner"];
+    shell = pkgs.fish;
+    openssh.authorizedKeys.keys = [
+      "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCyPk5WyFoWSvF4ozehxcVBoZ+UHgrI7VW/OoQfFFwIQe0qvetUZBMZwR2FwkLPAMZV8zz1v4EfncudEkVghy4P+/YVLlDjqDq9zwZnh8Nd/ifu84wmcNWHT2UcqnhjniCdshL8a44memzABnxfLLv+sXhP2x32cJAamo5y6fukr2qLp2jbXzR+3sv3klE0ruUXis/BR1lLqNJEYP8jB6fLn2sLKinnZPfn6DwVOk10mGeQsdME/eGl3phpjhODH9JW5V2V5nJBbC0rBnq+78dyArKVqjPSmIcSy72DEIpTctnMEN1W34BGrnsDd5Xd/DKxKxHKTMCHtZRwLC2X0NWN"
+      "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCMALVC8RDTHec+PC8y1s3tcpUAODgq6DEzQdHDf/cyvDMfmCaPiMxfIdmkns5lMa03hymIfSmLUF0jFFDc7biRp7uf9AAXNsrTmplHii0l0McuOOZGlSdZM4eL817P7UwJqFMxJyFXDjkubhQiX6kp25Kfuj/zLnupRCaiDvE7ho/xay6Jrv0XLz935TPDwkc7W1asLIvsZLheB+sRz9SMOb9gtrvk5WXZl5JTOFOLu+JaRwQLHL/xdcHJTOod7tqHYfpoC5JHrEwKzbhTOwxZBQBfTQjQktKENQtBxXHTe71rUEWfEZQGg60/BC4BrRmh4qJjlJu3v4VIhC7SSHn1"
+    ];
+  };
+  users.extraUsers.rj = {
+    isNormalUser = true;
+    extraGroups = ["wheel" "plugdev" "dialout"];
+  };
+  users.extraUsers.astro = {
+    isNormalUser = true;
+    extraGroups = ["plugdev" "dialout"];
+    shell = pkgs.bashInteractive;
+  };
+  users.extraUsers.nix = {
+    isNormalUser = true;
+  };
+  security.sudo.wheelNeedsPassword = false;
+  security.hideProcessInformation = true;
+  boot.kernel.sysctl."kernel.dmesg_restrict" = true;
+  services.udev.packages = [ pkgs.sane-backends ];
+
+  nix.distributedBuilds = true;
+  nix.buildMachines = [
+    {
+       hostName = "localhost";
+       maxJobs = 4;
+       system = "x86_64-linux";
+       supportedFeatures = ["big-parallel"];
+    }
+    {
+       hostName = "rpi-3";
+       sshUser = "nix";
+       sshKey = "/etc/nixos/secret/nix_id_rsa";
+       maxJobs = 1;
+       system = "aarch64-linux";
+    }
+  ];
+  services.hydra = {
+    enable = true;
+    package = pkgs.hydra-unstable;
+    useSubstitutes = true;
+    hydraURL = "https://nixbld.m-labs.hk";
+    notificationSender = "hydra@m-labs.hk";
+    minimumDiskFree = 15;  # in GB
+    minimumDiskFreeEvaluator = 1;
+    extraConfig =
+      ''
+      binary_cache_secret_key_file = /etc/nixos/secret/nixbld.m-labs.hk-1
+      max_output_size = 10000000000
+
+      <runcommand>
+        job = web:web:web
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/web
+      </runcommand>
+
+      <runcommand>
+        job = artiq:full:sipyco-manual-html
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/sipyco-manual-html
+      </runcommand>
+      <runcommand>
+        job = artiq:full:sipyco-manual-latexpdf
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/sipyco-manual-latexpdf
+      </runcommand>
+
+      <runcommand>
+        job = artiq:full-beta:artiq-manual-html
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/artiq-manual-html-beta
+      </runcommand>
+      <runcommand>
+        job = artiq:full-beta:artiq-manual-latexpdf
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/artiq-manual-latexpdf-beta
+      </runcommand>
+      <runcommand>
+        job = artiq:full-beta:conda-channel
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/artiq-conda-channel-beta
+      </runcommand>
+
+      <runcommand>
+        job = artiq:full:artiq-manual-html
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/artiq-manual-html
+      </runcommand>
+      <runcommand>
+        job = artiq:full:artiq-manual-latexpdf
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/artiq-manual-latexpdf
+      </runcommand>
+      <runcommand>
+        job = artiq:full:conda-channel
+        command = [ $(jq '.buildStatus' < $HYDRA_JSON) = 0 ] && ln -sfn $(jq -r '.outputs[0].path' < $HYDRA_JSON) ${hydraWwwOutputs}/artiq-conda-channel
+      </runcommand>
+      '';
+  };
+  systemd.services.hydra-www-outputs-init = {
+    description = "Set up a hydra-owned directory for build outputs";
+    wantedBy = [ "multi-user.target" ];
+    requiredBy = [ "hydra-queue-runner.service" ];
+    before = [ "hydra-queue-runner.service" ];
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = [ "${pkgs.coreutils}/bin/mkdir -p ${hydraWwwOutputs}" "${pkgs.coreutils}/bin/chown hydra-queue-runner:hydra ${hydraWwwOutputs}" ];
+    };
+  };
+
+
+  nix.extraOptions = ''
+    secret-key-files = /etc/nixos/secret/nixbld.m-labs.hk-1
+  '';
+  nix.sandboxPaths = ["/opt"];
+
+  services.munin-node.enable = true;
+  services.munin-cron = {
+    enable = true;
+     hosts = ''
+       [${config.networking.hostName}]
+       address localhost
+     '';
+  };
+  services.mlabs-backup.enable = true;
+
+  services.gitea = {
+    enable = true;
+    httpPort = 3001;
+    rootUrl = "https://git.m-labs.hk/";
+    appName = "M-Labs Git";
+    cookieSecure = true;
+    disableRegistration = true;
+    mailerPasswordFile = "/etc/nixos/secret/mailerpassword";
+    extraConfig =
+    ''
+    [mailer]
+    ENABLED = true
+    HOST = ssl.serverraum.org:587
+    FROM = sysop@m-labs.hk
+    USER = sysop@m-labs.hk
+
+    [service]
+    ENABLE_NOTIFY_MAIL = true
+
+    [attachment]
+    ALLOWED_TYPES = */*
+    '';
+  };
+  systemd.tmpfiles.rules = [
+    "L+ '${config.services.gitea.stateDir}/custom/templates/home.tmpl' - - - - ${./gitea-home.tmpl}"
+  ];
+
+  services.mattermost = {
+    enable = true;
+    siteUrl = "https://chat.m-labs.hk/";
+    mutableConfig = true;
+  };
+
+  services.matterbridge = {
+    enable = true;
+    configPath = "/etc/nixos/secret/matterbridge.toml";
+  };
+ 
+  nixpkgs.config.packageOverrides = super: let self = super.pkgs; in {
+    hydra-unstable = super.hydra-unstable.overrideAttrs(oa: {
+      patches = oa.patches or [] ++ [ ./hydra-conda.patch ./hydra-retry.patch ./hydra-unbreak-sysbuild.patch ];
+      hydraPath = oa.hydraPath + ":" + super.lib.makeBinPath [ super.jq ];
+    });
+    matterbridge = super.matterbridge.overrideAttrs(oa: {
+      patches = oa.patches or [] ++ [ ./matterbridge-disable-github.patch ];
+    });
+  };
+
+  security.acme.acceptTerms = true;
+  security.acme.email = "sb" + "@m-labs.hk";
+  security.acme.certs = {
+    "nixbld.m-labs.hk" = {
+      group = "nginx";
+      user = "nginx";
+      webroot = "/var/lib/acme/acme-challenge";
+      extraDomains = {
+        "m-labs.hk" = null;
+        "www.m-labs.hk" = null;
+        "conda.m-labs.hk" = null;
+        "lab.m-labs.hk" = null;
+        "git.m-labs.hk" = null;
+        "chat.m-labs.hk" = null;
+        "hooks.m-labs.hk" = null;
+        "forum.m-labs.hk" = null;
+        "perso.m-labs.hk" = null;
+        "nmigen.org" = null;
+        "www.nmigen.org" = null;
+
+        "openhardware.hk" = null;
+        "git.openhardware.hk" = null;
+      };
+    };
+  };
+  services.nginx = {
+    enable = true;
+    recommendedProxySettings = true;
+    recommendedGzipSettings = true;
+    virtualHosts = let
+      mainWebsite = {
+        addSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        root = "${hydraWwwOutputs}/web";
+        extraConfig = ''
+          error_page 404 /404.html;
+        '';
+        locations."^~ /fonts/".extraConfig = ''
+          expires 60d;
+        '';
+        locations."^~ /js/".extraConfig = ''
+          expires 60d;
+        '';
+        locations."/MathJax/" = {
+          alias = "/var/www/MathJax/";
+          extraConfig = ''
+            expires 60d;
+          '';
+        };
+
+        # legacy URLs, redirect to avoid breaking people's bookmarks
+        locations."/gateware.html".extraConfig = ''
+          return 301 /gateware/migen/;
+        '';
+        locations."/migen".extraConfig = ''
+          return 301 /gateware/migen/;
+        '';
+        locations."/artiq".extraConfig = ''
+          return 301 /experiment-control/artiq/;
+        '';
+        locations."/artiq/resources.html".extraConfig = ''
+          return 301 /experiment-control/resources/;
+        '';
+
+        # autogenerated manuals
+        locations."/artiq/sipyco-manual/" = {
+          alias = "${hydraWwwOutputs}/sipyco-manual-html/share/doc/sipyco-manual/html/";
+        };
+        locations."=/artiq/sipyco-manual.pdf" = {
+          alias = "${hydraWwwOutputs}/sipyco-manual-latexpdf/share/doc/sipyco-manual/SiPyCo.pdf";
+        };
+        locations."/artiq/manual-beta/" = {
+          alias = "${hydraWwwOutputs}/artiq-manual-html-beta/share/doc/artiq-manual/html/";
+        };
+        locations."=/artiq/manual-beta.pdf" = {
+          alias = "${hydraWwwOutputs}/artiq-manual-latexpdf-beta/share/doc/artiq-manual/ARTIQ.pdf";
+        };
+        locations."/artiq/manual/" = {
+          alias = "${hydraWwwOutputs}/artiq-manual-html/share/doc/artiq-manual/html/";
+        };
+        locations."=/artiq/manual.pdf" = {
+          alias = "${hydraWwwOutputs}/artiq-manual-latexpdf/share/doc/artiq-manual/ARTIQ.pdf";
+        };
+
+        # legacy content
+        locations."/migen/manual/" = {
+          alias = "/var/www/m-labs.hk.old/migen/manual/";
+        };
+        locations."/artiq/manual-release-4/" = {
+          alias = "/var/www/m-labs.hk.old/artiq/manual-release-4/";
+        };
+        locations."/artiq/manual-release-3/" = {
+          alias = "/var/www/m-labs.hk.old/artiq/manual-release-3/";
+        };
+        locations."/artiq/manual-release-2/" = {
+          alias = "/var/www/m-labs.hk.old/artiq/manual-release-2/";
+        };
+      };
+    in {
+      "m-labs.hk" = mainWebsite;
+      "www.m-labs.hk" = mainWebsite;
+      "lab.m-labs.hk" = {
+        addSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/munin/".alias = "/var/www/munin/";
+        locations."/munin".extraConfig = ''
+          auth_basic "Munin";
+          auth_basic_user_file /etc/nixos/secret/muninpasswd;
+        '';
+        locations."/homu/".proxyPass = "http://127.0.0.1:54856/";
+      };
+      "nixbld.m-labs.hk" = {
+        forceSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/".proxyPass = "http://127.0.0.1:3000";
+      };
+      "conda.m-labs.hk" = {
+        forceSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/artiq-beta/" = {
+          alias = "${hydraWwwOutputs}/artiq-conda-channel-beta/";
+          extraConfig = ''
+            autoindex on;
+            index bogus_index_file;
+          '';
+        };
+        locations."/artiq/" = {
+          alias = "${hydraWwwOutputs}/artiq-conda-channel/";
+          extraConfig = ''
+            autoindex on;
+            index bogus_index_file;
+          '';
+        };
+      };
+      "git.m-labs.hk" = {
+        forceSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/".proxyPass = "http://127.0.0.1:3001";
+        extraConfig = ''
+          client_max_body_size 300M;
+        '';
+      };
+      "chat.m-labs.hk" = {
+        forceSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/".proxyPass = "http://127.0.0.1:8065";
+        locations."~ /api/v[0-9]+/(users/)?websocket$".proxyPass = "http://127.0.0.1:8065";
+        locations."~ /api/v[0-9]+/(users/)?websocket$".proxyWebsockets = true;
+      };
+      "hooks.m-labs.hk" = {
+        forceSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/mattermost-github".extraConfig = ''
+          include ${pkgs.nginx}/conf/uwsgi_params;
+          uwsgi_pass unix:${config.services.uwsgi.runDir}/uwsgi-mgi.sock;
+        '';
+        locations."/rfq".extraConfig = ''
+          include ${pkgs.nginx}/conf/uwsgi_params;
+          uwsgi_pass unix:${config.services.uwsgi.runDir}/uwsgi-rfq.sock;
+        '';
+      };
+      "forum.m-labs.hk" = {
+        forceSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        root = "/var/www/flarum/public";
+        locations."~ \.php$".extraConfig = ''
+          fastcgi_pass unix:${config.services.phpfpm.pools.flarum.socket};
+          fastcgi_index index.php;
+        '';
+        extraConfig = ''
+          index index.php;
+          include /var/www/flarum/.nginx.conf;
+        '';
+      };
+      "perso.m-labs.hk" = {
+        addSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        root = "/var/www/perso";
+      };
+      "nmigen.org" = {
+        addSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/".extraConfig = ''
+          return 307 https://m-labs.hk/gateware/nmigen/;
+        '';
+      };
+      "www.nmigen.org" = {
+        addSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/".extraConfig = ''
+          return 307 https://m-labs.hk/gateware/nmigen/;
+        '';
+      };
+
+      "git.openhardware.hk" = {
+        forceSSL = true;
+        useACMEHost = "nixbld.m-labs.hk";
+        locations."/".proxyPass = "http://127.0.0.1:3002";
+        extraConfig = ''
+          client_max_body_size 300M;
+        '';
+      };
+    };
+  };
+  services.uwsgi = {
+    enable = true;
+    plugins = [ "python3" ];
+    instance = {
+      type = "emperor";
+      vassals = {
+        mattermostgithub = import ./mattermost-github-integration/uwsgi-config.nix { inherit config pkgs; };
+        rfq = import ./rfq/uwsgi-config.nix { inherit config pkgs; };
+      };
+    };
+  };
+  services.mysql = {
+    enable = true;
+    package = pkgs.mariadb;
+  };
+  services.phpfpm.pools.flarum = {
+    user = "nobody";
+    settings = {
+      "listen.owner" = "nginx";
+      "listen.group" = "nginx";
+      "listen.mode" = "0600";
+      "pm" = "dynamic";
+      "pm.max_children" = 5;
+      "pm.start_servers" = 2;
+      "pm.min_spare_servers" = 1;
+      "pm.max_spare_servers" = 3;
+      "pm.max_requests" = 500;
+    };
+  };
+
+  services.homu = {
+    enable = true;
+    config = "/etc/nixos/secret/homu.toml";
+  };
+
+  mailserver = {
+    enable = true;
+    localDnsResolver = false;  # conflicts with dnsmasq
+    # Some mail servers do reverse DNS lookups to filter spam.
+    # Getting a proper reverse DNS record from ISP is difficult, so use whatever already exists.
+    fqdn = "42-200-147-171.static.imsbiz.com";
+    domains = [ "nmigen.org" ];
+    loginAccounts = (import /etc/nixos/secret/email_accounts.nix);
+    certificateScheme = 3;
+  };
+  security.acme.certs."${config.mailserver.fqdn}".extraDomains = {
+    "mail.nmigen.org" = null;
+  };
+
+  containers.openhardwarehk = {
+    autoStart = true;
+    config =
+      { config, pkgs, ... }:
+      {
+        services.gitea = {
+          enable = true;
+          httpPort = 3002;
+          rootUrl = "https://git.openhardware.hk/";
+          appName = "Open Hardware HK";
+          cookieSecure = true;
+          disableRegistration = true;
+          extraConfig =
+          ''
+          [attachment]
+          ALLOWED_TYPES = */*
+          '';
+        };
+      };
+  };
+
+  # This value determines the NixOS release with which your system is to be
+  # compatible, in order to avoid breaking some software such as database
+  # servers. You should change this only after NixOS release notes say you
+  # should.
+  system.stateVersion = "18.09"; # Did you read the comment?
+}
--- a/nixbld-etc-nixos/gitea-home.tmpl
+++ b/nixbld-etc-nixos/gitea-home.tmpl
@ -0,0 +1,23 @@
+{{template "base/head" .}}
+<div class="home">
+	<div class="ui stackable middle very relaxed page grid">
+		<div class="sixteen wide center aligned centered column">
+			<div>
+				<img class="logo" src="{{AppSubUrl}}/img/gitea-lg.png" />
+			</div>
+			<div class="hero">
+				<h1 class="ui icon header title">
+					{{AppName}}
+				</h1>
+			</div>
+		</div>
+	</div>
+	<div class="ui stackable middle very relaxed page grid">
+		<div class="sixteen wide center column">
+			<p class="large">
+				Welcome! This Gitea instance is here to support projects related to <a href="https://m-labs.hk">M-Labs</a>. You may want to browse the <a href="https://git.m-labs.hk/M-Labs/">M-Labs organization</a> where many projects are located. If you would like an account (we give them to anyone who wants to contribute on projects related to Sinara, ARTIQ, nMigen, etc.), simply write a short email to sb@m-***.hk stating the username you would like to have.
+			</p>
+		</div>
+	</div>
+</div>
+{{template "base/footer" .}}
--- a/nixbld-etc-nixos/homu/disable-ssh-host-keycheck.patch
+++ b/nixbld-etc-nixos/homu/disable-ssh-host-keycheck.patch
@ -0,0 +1,13 @@
+diff --git a/homu/git_helper.py b/homu/git_helper.py
+index 0f70c69..f53fb57 100755
+--- a/homu/git_helper.py
+++ b/homu/git_helper.py
+@@ -7,7 +7,7 @@ SSH_KEY_FILE = os.path.join(os.path.dirname(__file__), '../cache/key')
+ 
+ 
+ def main():
+-    args = ['ssh', '-i', SSH_KEY_FILE, '-S', 'none'] + sys.argv[1:]
+    args = ['ssh', '-o', 'StrictHostKeyChecking=no', '-i', SSH_KEY_FILE, '-S', 'none'] + sys.argv[1:]
+     os.execvp('ssh', args)
+ 
+ 
--- a/nixbld-etc-nixos/homu/nixos-module.nix
+++ b/nixbld-etc-nixos/homu/nixos-module.nix
@ -0,0 +1,52 @@
+{ config, pkgs, lib, ... }:
+with lib;
+let
+  homu = pkgs.callPackage ./pkg.nix {};
+  cfg = config.services.homu;
+in
+
+{
+  options.services.homu = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable the bot";
+    };
+    dbDir = mkOption {
+      type = types.str;
+      default = "/var/db/homu";
+      description = "Path to the database file (use the same path in config.toml)";
+    };
+    config = mkOption {
+      description = "Location of config.toml";
+      type = types.str;
+    };
+  };
+
+  config = mkIf cfg.enable {
+    users.users.homu = {
+      group = "homu";
+      home = cfg.dbDir;
+      createHome = true;
+    };
+    users.groups.homu = {};
+
+    systemd.services.homu = {
+      description = "Homu bot";
+      wantedBy = [ "multi-user.target" ];
+      after    = [ "network.target" ];
+      serviceConfig = {
+        Type = "simple";
+        ExecStart = "${homu}/bin/homu -c ${cfg.config}";
+
+        Restart = "always";
+        RestartSec = "5sec";
+
+        User = "homu";
+        Group = "homu";
+      };
+    };
+  };
+
+}
+  
--- a/nixbld-etc-nixos/homu/patch-cache-directory.patch
+++ b/nixbld-etc-nixos/homu/patch-cache-directory.patch
@ -0,0 +1,26 @@
+diff --git a/homu/git_helper.py b/homu/git_helper.py
+index 0f70c69..732230c 100755
+--- a/homu/git_helper.py
+++ b/homu/git_helper.py
+@@ -3,7 +3,7 @@
+ import sys
+ import os
+ 
+-SSH_KEY_FILE = os.path.join(os.path.dirname(__file__), '../cache/key')
+SSH_KEY_FILE = os.path.expanduser("~/cache/key")
+ 
+ 
+ def main():
+diff --git a/homu/main.py b/homu/main.py
+index 16b60a2..a2e109a 100644
+--- a/homu/main.py
+++ b/homu/main.py
+@@ -649,7 +649,7 @@ def git_push(git_cmd, branch, state):
+ 
+ 
+ def init_local_git_cmds(repo_cfg, git_cfg):
+-    fpath = 'cache/{}/{}'.format(repo_cfg['owner'], repo_cfg['name'])
+    fpath = '{}/cache/{}/{}'.format(os.path.expanduser("~"), repo_cfg['owner'], repo_cfg['name'])
+     url = 'git@github.com:{}/{}.git'.format(repo_cfg['owner'], repo_cfg['name'])  # noqa
+ 
+     if not os.path.exists(SSH_KEY_FILE):
--- a/nixbld-etc-nixos/homu/pkg.nix
+++ b/nixbld-etc-nixos/homu/pkg.nix
@ -0,0 +1,34 @@
+{ python3Packages, python3, fetchFromGitHub, git, openssh }:
+
+let
+  uritemplate_0_2_0 = python3Packages.github3_py.overrideAttrs(oa: rec {
+  	version = "0.2.0";
+  	src = python3Packages.fetchPypi {
+      pname = "uritemplate.py";
+      inherit version;
+      sha256 = "1pfk04pmnysz0383lwzgig8zqlwiv2n4pmq51f0mc60zz1jimq4g";
+    };
+  });
+  github3_py_0_9_6 = python3Packages.github3_py.overrideAttrs(oa: rec {
+    version = "0.9.6";
+    src = python3Packages.fetchPypi {
+      pname = "github3.py";
+      inherit version;
+      sha256 = "1i8xnh586z4kka7pjl7cy08fmzjs14c8jdp8ykb9jjpzsy2xncdq";
+    };
+    propagatedBuildInputs = [ python3Packages.requests uritemplate_0_2_0 ];
+  });
+in
+  python3Packages.buildPythonApplication {
+    name = "homu";
+    src = fetchFromGitHub {
+      owner = "servo";
+      repo = "homu";
+      rev = "2ea53e76ebac3e5fa11bc39054b3cd4c42eff607";
+      sha256 = "1ih7s8zfbpq0qb9vqbxzr0r4s9ff52l4ipr916kwbck3ygliq3r9";
+    };
+    patches = [ ./patch-cache-directory.patch ./disable-ssh-host-keycheck.patch ];
+    postInstall = "chmod 755 $out/${python3.sitePackages}/homu/git_helper.py";
+    propagatedBuildInputs = [ github3_py_0_9_6 git openssh ] ++ (with python3Packages; [ toml jinja2 requests bottle waitress retrying ]);
+    checkPhase = "python -m unittest discover tests -v";
+  }
--- a/nixbld-etc-nixos/hydra-conda.patch
+++ b/nixbld-etc-nixos/hydra-conda.patch
@ -0,0 +1,47 @@
+commit 5aa5f8d5742883d41d7278a2c8bc2c9a2ddfef45
+Author: Sebastien Bourdeauducq <sb@m-labs.hk>
+Date:   Sun Apr 14 18:25:27 2019 +0800
+
+    add SVG icon for conda package
+
+diff --git a/src/root/product-list.tt b/src/root/product-list.tt
+index 298d0a66..85914bbd 100644
+--- a/src/root/product-list.tt
+++ b/src/root/product-list.tt
+@@ -157,6 +157,11 @@
+             <img src="[% c.uri_for("/static/images/debian.png") %]" alt="DEB" />
+           </td>
+           <td>Debian package</td>
+        [% CASE "conda" %]
+          <td>
+            <img src="[% c.uri_for("/static/images/conda.svg") %]" width="32" height="32" alt="Conda" />
+          </td>
+          <td>Conda package</td>
+         [% CASE "iso" %]
+           <td>
+             <img src="[% c.uri_for("/static/images/iso.png") %]" alt="ISO" />
+diff --git a/src/root/static/images/conda.svg b/src/root/static/images/conda.svg
+new file mode 100644
+index 00000000..67859731
+--- /dev/null
+++ b/src/root/static/images/conda.svg
+@@ -0,0 +1,18 @@
+<svg width="128" height="128" style="enable-background:new 0 0 128 128;" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <g id="g2">
+    <g>
+      <path d="M118.89,75.13c-1.31-2.72-3.46-5.53-6.97-7.33c-2.37-1.48-4.57-2.24-6.01-2.63 c1.53-5.6-0.64-10.06-3.69-13.39c-4.53-4.88-9.27-5.59-9.27-5.59l-0.01,0c1.56-3.03,2.15-6.54,1.36-9.99 c-1-4.26-3.29-6.94-6.31-8.73c-3.09-1.83-6.91-2.73-10.83-3.43c-1.88-0.34-9.81-1.45-13.1-6c-2.65-3.69-2.73-10.33-3.45-12.32 c-0.77-2.05-3.38-1.15-6.23,0.76c-3.33,2.22-10.23,9.35-12.89,16.49c-2.03,5.47-2.08,10.21-1.28,13.89 c-3.29,0.55-5.76,1.66-6.23,1.88c-0.16,0.05-0.32,0.1-0.49,0.17c-3.01,1.24-9.43,7.02-10.01,15.85c-0.2,3.14,0.21,6.31,1.2,9.26 c-3.94,1.1-6.22,2.54-6.26,2.57c-2,0.75-5.18,2.95-6.15,4.13c-1.97,2.38-3.34,5.21-4.15,8.18C6.35,85.36,7,92.71,10.14,98.67 c1.74,3.31,4.12,6.83,6.74,9.52c8.55,8.79,23.31,12.11,34.96,14.03c14.19,2.34,29.05,1.52,42.33-3.97 c19.92-8.22,25.22-21.44,26-25.17C121.92,84.77,119.8,77,118.89,75.13z" style="fill:#865D53;"/>
+      <g>
+        <g>
+          <ellipse cx="85.95" cy="66.39" rx="16.61" ry="15.5" style="fill:#FFFFFF;" transform="matrix(0.1106 -0.9939 0.9939 0.1106 10.453 144.4706)"/>
+          <path d="M92.63,66.36c-0.23,3.3-3.14,5.82-6.49,5.62c-3.36-0.19-5.9-3.04-5.67-6.34 c0.22-3.31,3.12-5.82,6.48-5.62C90.31,60.21,92.86,63.06,92.63,66.36" style="fill:#2F2F2F;"/>
+        </g>
+        <g>
+          <ellipse cx="42.46" cy="66.4" rx="15.5" ry="16.61" style="fill:#FFFFFF;" transform="matrix(0.9972 -0.0752 0.0752 0.9972 -4.8714 3.3796)"/>
+          <path d="M49.02,65.13c0.38,3.29-2.01,6.3-5.34,6.72c-3.34,0.43-6.36-1.9-6.74-5.18 c-0.4-3.29,1.99-6.3,5.33-6.73C45.6,59.52,48.63,61.85,49.02,65.13" style="fill:#2F2F2F;"/>
+        </g>
+      </g>
+      <path d="M87.35,89.46c-2.22-1.5-5.02-0.51-7.49,0c-6.9,1.42-12.95,1.48-15.86,1.48 c-2.91,0-8.96-0.06-15.86-1.48c-2.47-0.51-5.27-1.5-7.49,0c-2.82,1.9-0.74,8.74,3.7,13.36c2.68,2.79,9.07,8.21,19.66,8.21 c10.58,0,16.97-5.42,19.66-8.21C88.09,98.2,90.17,91.37,87.35,89.46z" style="fill:#ED6D31;"/>
+    </g>
+  </g>
+</svg>
+\ No newline at end of file
--- a/nixbld-etc-nixos/hydra-retry.patch
+++ b/nixbld-etc-nixos/hydra-retry.patch
@ -0,0 +1,19 @@
+commit 86bf81c0b8a51bffa4b4b566e1caaac6f0e041d3
+Author: Sebastien Bourdeauducq <sb@m-labs.hk>
+Date:   Thu Mar 14 17:45:32 2019 +0800
+
+    add option to disable retries on transient failures
+
+diff --git a/src/hydra-queue-runner/build-remote.cc b/src/hydra-queue-runner/build-remote.cc
+index 69c430eb..bdbc808d 100644
+--- a/src/hydra-queue-runner/build-remote.cc
+++ b/src/hydra-queue-runner/build-remote.cc
+@@ -344,7 +344,7 @@ void State::buildRemote(ref<Store> destStore,
+                     break;
+                 case BuildResult::TransientFailure:
+                     result.stepStatus = bsFailed;
+-                    result.canRetry = true;
+                    result.canRetry = get(step->drv->env, "__hydraRetry").value_or("1") == "1";
+                     result.errorMsg = "";
+                     break;
+                 case BuildResult::TimedOut:
--- a/nixbld-etc-nixos/hydra-unbreak-sysbuild.patch
+++ b/nixbld-etc-nixos/hydra-unbreak-sysbuild.patch
@ -0,0 +1,25 @@
+diff --git a/src/lib/Hydra/Schema/Builds.pm b/src/lib/Hydra/Schema/Builds.pm
+index d4334300..014d07ce 100644
+--- a/src/lib/Hydra/Schema/Builds.pm
+++ b/src/lib/Hydra/Schema/Builds.pm
+@@ -608,6 +608,7 @@ makeQueries('', "");
+ makeQueries('ForProject', "and project = ?");
+ makeQueries('ForJobset', "and jobset_id = ?");
+ makeQueries('ForJob', "and jobset_id = ? and job = ?");
+makeQueries('ForJobName', "and jobset_id = (select id from jobsets j where j.name = ?) and job = ?");
+ 
+ 
+ my %hint = (
+diff --git a/src/script/hydra-eval-jobset b/src/script/hydra-eval-jobset
+index ea336bfc..2f208418 100755
+--- a/src/script/hydra-eval-jobset
+++ b/src/script/hydra-eval-jobset
+@@ -142,7 +142,7 @@ sub fetchInputSystemBuild {
+     $projectName ||= $project->name;
+     $jobsetName ||= $jobset->name;
+ 
+-    my @latestBuilds = $db->resultset('LatestSucceededForJob')
+    my @latestBuilds = $db->resultset('LatestSucceededForJobName')
+         ->search({}, {bind => [$jobsetName, $jobName]});
+ 
+     my @validBuilds = ();
--- a/nixbld-etc-nixos/matterbridge-disable-github.patch
+++ b/nixbld-etc-nixos/matterbridge-disable-github.patch
@ -0,0 +1,15 @@
+diff --git a/bridge/mattermost/helpers.go b/bridge/mattermost/helpers.go
+index 14b7469d..d9b77bdf 100644
+--- a/bridge/mattermost/helpers.go
+++ b/bridge/mattermost/helpers.go
+@@ -206,6 +206,10 @@ func (b *Bmattermost) skipMessage(message *matterclient.Message) bool {
+ 		return true
+ 	}
+ 
+	if message.Username == "github" {
+		return true
+	}
+
+ 	// if the message has reactions don't repost it (for now, until we can correlate reaction with message)
+ 	if message.Post.HasReactions {
+ 		return true
--- a/nixbld-etc-nixos/mattermost-github-integration/pkg.nix
+++ b/nixbld-etc-nixos/mattermost-github-integration/pkg.nix
@ -0,0 +1,32 @@
+{ fetchFromGitHub, python3Packages }:
+with python3Packages;
+
+buildPythonPackage rec {
+  pname = "mattermost-github-integration";
+  version = "0.0.0-unstable";
+  src = fetchFromGitHub {
+    owner = "softdevteam";
+    repo = "mattermost-github-integration";
+    rev = "1124a0ff233b50ed6070cb84cfffd128ad219831";
+    sha256 = "1hfvjaxjhliy8sv9j3616fkdwd2jqhfsj9ai7ggx88zhxknrfx85";
+  };
+  propagatedBuildInputs = [
+    appdirs
+    click
+    flask
+    itsdangerous
+    jinja2
+    markupsafe
+    olefile
+    packaging
+    pillow
+    pyparsing
+    requests
+    six
+    werkzeug
+  ];
+  checkInputs = [
+    pytest
+  ];
+  doCheck = true;
+}
--- a/nixbld-etc-nixos/mattermost-github-integration/uwsgi-config.nix
+++ b/nixbld-etc-nixos/mattermost-github-integration/uwsgi-config.nix
@ -0,0 +1,15 @@
+{ config, pkgs }:
+
+let
+  pkg = pkgs.callPackage ./pkg.nix {};
+in {
+  type = "normal";
+  pythonPackages = self: [ pkg ];
+  module = "mattermostgithub:app";
+  env = [
+    "MGI_CONFIG_FILE=${./../secret/mattermost-github-integration.py}"
+  ];
+  socket = "${config.services.uwsgi.runDir}/uwsgi-mgi.sock";
+  # allow access from nginx
+  chmod-socket = 666;
+}
--- a/nixbld-etc-nixos/notifico/nixos-module.nix
+++ b/nixbld-etc-nixos/notifico/nixos-module.nix
@ -0,0 +1,93 @@
+{ config, pkgs, lib, ... }:
+with lib;
+let
+  notifico = (pkgs.callPackage ./pkg.nix {})
+    .overrideAttrs (attrs: {
+      buildInputs = attrs.buildInputs ++ [ pkgs.makeWrapper ];
+      # Extend the module path so that local_config.py can be found
+      postInstall = ''
+        ${attrs.postInstall}
+
+        wrapProgram $out/bin/notifico \
+          --set PYTHONPATH "$${PYTHONPATH}:${cfg.dbDir}"
+      '';
+    });
+  cfg = config.services.notifico;
+in
+
+{
+  options.services.notifico = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable the commit notification service";
+    };
+    enableLocalRedis = mkOption {
+      type = types.bool;
+      default = true;
+      description = "Enable a local Redis server";
+    };
+    dbDir = mkOption {
+      type = types.str;
+      default = "/var/db/notifico";
+      description = "Home directory and location of the database file";
+    };
+    config = mkOption {
+      description = "Path to local_config.py, https://github.com/notifico/notifico/raw/master/notifico/config.py";
+      type = types.str;
+    };
+  };
+
+  config = mkIf cfg.enable {
+    users.users.notifico = {
+      group = "notifico";
+      home = cfg.dbDir;
+      createHome = true;
+    };
+    users.groups.notifico = {};
+
+    services.redis = mkIf cfg.enableLocalRedis {
+      enable = true;
+      bind = "127.0.0.1";
+    };
+
+    systemd.services =
+      let
+        User = "notifico";
+        Group = "notifico";
+        WorkingDirectory = "${cfg.dbDir}";
+        ExecStartPre = [
+          "${pkgs.coreutils}/bin/rm -f local_config.pyc"
+          "${pkgs.coreutils}/bin/ln -sf ${cfg.config} local_config.py"
+        ];
+
+        notifico-init = {
+          description = "Notifico initialization";
+          serviceConfig = {
+            inherit User Group WorkingDirectory ExecStartPre;
+            Type = "oneshot";
+            ExecStart = "${notifico}/bin/notifico init";
+          };
+        };
+        notificoService = component: {
+          description = "Notifico ${component}";
+          wantedBy = [ "multi-user.target" ];
+          after    = [ "network.target" "notifico-init.service" ];
+          requires = [ "notifico-init.service" ];
+          serviceConfig = {
+            inherit User Group WorkingDirectory ExecStartPre;
+            Type = "simple";
+            ExecStart = "${notifico}/bin/notifico ${component}";
+
+            Restart = "always";
+            RestartSec = "5sec";
+          };
+        };
+      in {
+        inherit notifico-init;
+        notifico-www = notificoService "www";
+        notifico-worker = notificoService "worker";
+        notifico-bots = notificoService "bots";
+      };
+  };
+}
--- a/nixbld-etc-nixos/notifico/pkg.nix
+++ b/nixbld-etc-nixos/notifico/pkg.nix
@ -0,0 +1,107 @@
+{ python2Packages, python2, fetchFromGitHub, fetchurl }:
+
+let
+  Flask-Gravatar = python2Packages.buildPythonPackage {
+    name = "Flask-Gravatar";
+    src = python2Packages.fetchPypi {
+      pname = "Flask-Gravatar";
+      version = "0.5.0";
+      sha256 = "1qb2ylirjajdqsmldhwfdhf8i86k7vlh3y4gnqfqj4n6q8qmyrk0";
+    };
+    propagatedBuildInputs = with python2Packages; [
+      pytestrunner
+      flask
+    ];
+    checkInputs = with python2Packages; [
+      check-manifest
+      coverage
+      isort
+      pydocstyle
+      pytestcache
+      pytestcov
+      pytestpep8
+      pytest
+      pygments
+    ];
+  };
+  utopia = python2Packages.buildPythonPackage {
+    name = "utopia";
+    src = fetchFromGitHub {
+      owner = "notifico";
+      repo = "utopia";
+      rev = "70293ed5e1ca55232e0fae71061e7e9b9b29be6f";
+      sha256 = "11cnh9l4d9jlhafnfis9si6kgk9zsdd5439qnhxh6dca3x4a986q";
+    };
+    propagatedBuildInputs = with python2Packages; [
+      gevent
+      blinker
+    ];
+    doCheck = false;
+  };
+  Flask-WTF = python2Packages.flask_wtf.overrideAttrs(oa: rec {
+  	version = "0.8.4";
+  	src = python2Packages.fetchPypi {
+      pname = "Flask-WTF";
+      inherit version;
+      sha256 = "1khbwmlrcnk9f46f7kf531n06pkyfs6nc8fk273js9mj2igngg2y";
+    };
+  });
+  Flask-XML-RPC = python2Packages.flask_wtf.overrideAttrs(oa: rec {
+  	version = "0.1.2";
+  	src = python2Packages.fetchPypi {
+      pname = "Flask-XML-RPC";
+      inherit version;
+      sha256 = "1dwalj7pc5iid9l1k50q5mllirnn9f5s7jq54a66x48a4j179p2a";
+    };
+  });
+in
+  python2Packages.buildPythonApplication {
+    name = "notifico";
+    src = fetchFromGitHub {
+      owner = "notifico";
+      repo = "notifico";
+      rev = "6af849e4c75dff4d740051676f5a2093a44efcee";
+      sha256 = "18jifqdvjy4x5s1bh7vx501pin52g4n3hhw1z4m2c0h512z4spdr";
+    };
+    patches = [
+      (fetchurl {
+        url = https://github.com/whitequark/notifico/commit/22b582fad6cb97af6f7437e8462d720ddacc42ef.patch;
+        sha256 = "0w8i8hf1r8b0p1y1zn9vyvnyi20qp120aiyalqymhsxsh17mma52";
+      })
+    ];
+    propagatedBuildInputs = with python2Packages; [
+      flask
+      Flask-WTF
+      Flask-Gravatar
+      flask_sqlalchemy
+      Flask-XML-RPC
+      flask_mail
+      flask-caching
+      Fabric
+      sqlalchemy
+      utopia
+      gevent
+      oauth2
+      redis
+      gunicorn
+      requests
+      PyGithub
+      xmltodict
+      unidecode
+      raven
+      blinker
+      docopt
+      celery
+    ];
+    postInstall = ''
+      mkdir $out/bin
+      cat << EOF > $out/bin/notifico
+      #!${python2}/bin/python
+      import sys
+      from notifico.__main__ import main
+
+      sys.exit(main(sys.argv))
+      EOF
+      chmod +x $out/bin/notifico
+    '';
+  }
--- a/nixbld-etc-nixos/rfq/pkg.nix
+++ b/nixbld-etc-nixos/rfq/pkg.nix
@ -0,0 +1,9 @@
+{ python3Packages, runCommand }:
+
+# Note: we do not use fetchgit but a local copy instead to avoid
+# chicken-and-egg problem if reinstalling nixbld.m-labs.hk from scratch.
+with python3Packages; buildPythonPackage rec {
+  name = "rfq";
+  src = ./src;
+  propagatedBuildInputs = [ flask flask_mail python-dotenv ];
+}
--- a/nixbld-etc-nixos/rfq/src/requirements.txt
+++ b/nixbld-etc-nixos/rfq/src/requirements.txt
@ -0,0 +1,10 @@
+blinker
+click
+Flask
+Flask-Mail
+itsdangerous
+Jinja2
+MarkupSafe
+python-dotenv
+six
+Werkzeug
--- a/nixbld-etc-nixos/rfq/src/rfq/init.py
+++ b/nixbld-etc-nixos/rfq/src/rfq/init.py
@ -0,0 +1,75 @@
+from os import getenv
+
+from dotenv import load_dotenv
+from flask import Flask
+from flask import current_app
+from flask import json
+from flask import jsonify
+from flask import make_response
+from flask import request
+from flask_mail import Mail
+from flask_mail import Message
+from werkzeug.middleware.proxy_fix import ProxyFix
+
+
+load_dotenv()
+
+app = Flask(__name__)
+app.config.update(
+    DEBUG=getenv("FLASK_DEBUG") == "True",
+    MAIL_SERVER=getenv("FLASK_MAIL_SERVER"),
+    MAIL_PORT=getenv("FLASK_MAIL_PORT"),
+    MAIL_USE_SSL=getenv("FLASK_MAIL_USE_SSL"),
+    MAIL_DEBUG=False,
+    MAIL_USERNAME=getenv("FLASK_MAIL_USERNAME"),
+    MAIL_PASSWORD=getenv("FLASK_MAIL_PASSWORD"),
+    MAIL_RECIPIENT=getenv("FLASK_MAIL_RECIPIENT"),
+    MAIL_SENDER=getenv("FLASK_MAIL_SENDER")
+)
+app.wsgi_app = ProxyFix(app.wsgi_app)
+
+mail = Mail(app)
+
+
+@app.after_request
+def after(response):
+    response.headers["Access-Control-Allow-Origin"] = "*"
+    response.headers["Access-Control-Allow-Headers"] = "*"
+    return response
+
+
+@app.route("/rfq", methods=["POST"])
+def send_rfq():
+    payload = request.json
+    payload = json.loads(json.htmlsafe_dumps(payload))
+
+    if payload is None:
+        resp = jsonify(error="invalid data")
+        return make_response(resp, 400)
+
+    if "email" not in payload:
+        resp = jsonify(error="missing email")
+        return make_response(resp, 400)
+
+    if "note" not in payload:
+        resp = jsonify(error="missing note")
+        return make_response(resp, 400)
+
+    if "configuration" not in payload:
+        resp = jsonify(error="missing configuration")
+        return make_response(resp, 400)
+
+    sender = current_app.config["MAIL_SENDER"]
+    recipient = current_app.config["MAIL_RECIPIENT"]
+
+    msg = Message(
+        "RFQ for Sinara hardware from {}".format(payload["email"]),
+        sender=sender,
+        recipients=[recipient, payload["email"]])
+    msg.body = ("From: {}\nConfiguration: {}\nNote: {}"
+        .format(payload["email"], payload["configuration"], payload["note"]))
+
+    with mail.connect() as conn:
+        conn.send(msg)
+
+    return jsonify("ok")
--- a/nixbld-etc-nixos/rfq/src/setup.py
+++ b/nixbld-etc-nixos/rfq/src/setup.py
@ -0,0 +1,14 @@
+from setuptools import setup
+from setuptools import find_packages
+
+setup(
+    name='rfq',
+    version='1.0.0',
+    packages=find_packages(),
+    zip_safe=False,
+    install_requires=[
+        'Flask',
+        'Flask-Mail',
+        'python-dotenv'
+    ]
+)
--- a/nixbld-etc-nixos/rfq/uwsgi-config.nix
+++ b/nixbld-etc-nixos/rfq/uwsgi-config.nix
@ -0,0 +1,21 @@
+{ config, pkgs }:
+
+let
+  pkg = pkgs.callPackage ./pkg.nix {};
+in {
+  type = "normal";
+  pythonPackages = self: [ pkg ];
+  module = "rfq:app";
+  env = [
+    "FLASK_MAIL_SERVER=ssl.serverraum.org"
+    "FLASK_MAIL_PORT=465"
+    "FLASK_MAIL_USE_SSL=True"
+    "FLASK_MAIL_USERNAME=sales@m-labs.hk"
+    "FLASK_MAIL_PASSWORD=${import /etc/nixos/secret/sales_password.nix}"
+    "FLASK_MAIL_RECIPIENT=sales@m-labs.hk"
+    "FLASK_MAIL_SENDER=sales@m-labs.hk"
+  ];
+  socket = "${config.services.uwsgi.runDir}/uwsgi-rfq.sock";
+  # allow access from nginx
+  chmod-socket = 666;
+}
--- a/nixbld-etc-nixos/secret_permissions.txt
+++ b/nixbld-etc-nixos/secret_permissions.txt
@ -0,0 +1,11 @@
+-rw------- 1 root         root           backup-passphrase
+-rw------- 1 root         root           email_accounts.nix
+-rw------- 1 homu         homu           homu.toml
+-rw-rw---- 1 gitea        gitea          mailerpassword
+-rw------- 1 matterbridge matterbridge   matterbridge.toml
+-rw------- 1 uwsgi        uwsgi          mattermost-github-integration.py
+-rw------- 1 nginx        nginx          muninpasswd
+-rw-rw---- 1 hydra        hydra          nixbld.m-labs.hk-1
+-rw-rw---- 1 hydra        hydra          nix_id_rsa
+-rw------- 1 root         root           rclone.conf
+-rw------- 1 root         root           wifi_password.nix
--- a/nixops/chiron-hardware-configuration.nix
+++ b/nixops/chiron-hardware-configuration.nix
@ -0,0 +1,33 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [ <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
+    ];
+
+  boot.initrd.availableKernelModules = [ "xhci_pci" "ahci" "nvme" "usbhid" "usb_storage" "sd_mod" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" =
+    { device = "/dev/disk/by-uuid/89db7e45-7b7e-44ec-bebc-a02935cc5ba0";
+      fsType = "ext4";
+    };
+
+  fileSystems."/boot" =
+    { device = "/dev/disk/by-uuid/060C-8772";
+      fsType = "vfat";
+    };
+
+  swapDevices = [ ];
+
+  nix.maxJobs = lib.mkDefault 16;
+  powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+}
--- a/nixops/cnc-hardware-configuration.nix
+++ b/nixops/cnc-hardware-configuration.nix
@ -0,0 +1,29 @@
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [ <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
+    ];
+
+  boot.initrd.availableKernelModules = [ "ata_generic" "uhci_hcd" "ehci_pci" "ahci" "usb_storage" "usbhid" "floppy" "sd_mod" "sr_mod" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" =
+    { device = "/dev/disk/by-uuid/35d9c50c-e479-43a9-8324-b8ded5b71844";
+      fsType = "ext4";
+    };
+
+  swapDevices =
+    [ { device = "/dev/disk/by-uuid/d8480389-c558-4c46-a58f-00207315dbdd"; }
+    ];
+
+  nix.maxJobs = lib.mkDefault 2;
+
+  boot.loader.grub.enable = true;
+  boot.loader.grub.version = 2;
+  boot.loader.grub.device = "/dev/sda";
+
+  services.xserver.videoDrivers = ["intel"];
+}
--- a/nixops/common-users.nix
+++ b/nixops/common-users.nix
@ -0,0 +1,58 @@
+{ pkgs, ... }:
+
+{
+  sb = {
+    isNormalUser = true;
+    extraGroups = ["wheel" "plugdev" "dialout"];
+    openssh.authorizedKeys.keys = [
+      "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCyPk5WyFoWSvF4ozehxcVBoZ+UHgrI7VW/OoQfFFwIQe0qvetUZBMZwR2FwkLPAMZV8zz1v4EfncudEkVghy4P+/YVLlDjqDq9zwZnh8Nd/ifu84wmcNWHT2UcqnhjniCdshL8a44memzABnxfLLv+sXhP2x32cJAamo5y6fukr2qLp2jbXzR+3sv3klE0ruUXis/BR1lLqNJEYP8jB6fLn2sLKinnZPfn6DwVOk10mGeQsdME/eGl3phpjhODH9JW5V2V5nJBbC0rBnq+78dyArKVqjPSmIcSy72DEIpTctnMEN1W34BGrnsDd5Xd/DKxKxHKTMCHtZRwLC2X0NWN"
+      "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCMALVC8RDTHec+PC8y1s3tcpUAODgq6DEzQdHDf/cyvDMfmCaPiMxfIdmkns5lMa03hymIfSmLUF0jFFDc7biRp7uf9AAXNsrTmplHii0l0McuOOZGlSdZM4eL817P7UwJqFMxJyFXDjkubhQiX6kp25Kfuj/zLnupRCaiDvE7ho/xay6Jrv0XLz935TPDwkc7W1asLIvsZLheB+sRz9SMOb9gtrvk5WXZl5JTOFOLu+JaRwQLHL/xdcHJTOod7tqHYfpoC5JHrEwKzbhTOwxZBQBfTQjQktKENQtBxXHTe71rUEWfEZQGg60/BC4BrRmh4qJjlJu3v4VIhC7SSHn1"
+    ];
+  };
+  rj = {
+    isNormalUser = true;
+    extraGroups = ["wheel" "plugdev" "dialout"];
+    openssh.authorizedKeys.keys = [
+      "ssh-rsa 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 rj@lab.m-labs.hk"
+      "ssh-rsa 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 robert-jordens-rsa4096"
+      "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCUdbne3NtIG+iy/jer76/OY+IksuS3BDLSXPnWrGejWnig9h+L6sUV0lEVI6dqp+W/b8jWqPB8nh5S0NZsCd3Ta3Go82k/SPPkh9lB2PpfquhCjLnmC/RNc3TgC4FuiS+NZHqXaTggYHubNwEK+8gynMqkMQXjOGU02U0CtUfsYdAm75AW60DySZCRNwOcU0Ndpn1UCpha7fL1k179Dd/OtArkYsIL24ohlfxFeOB3jGYQK6ATmzbvCRjwIKXcyECuajWwfnDg9FtDWrqHNzu5dJlvmxoWm8zCDgMj53uiA7TjujQN81MYrIJNeEwSr5jXQMqzA3mzlk4k3Z0qs3TP robert-jordens-64FEFBAF-4D0749B2-rsa2048"
+      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMUaB2G1jexxfkdlly3fdWslH54/s/bOuvk9AxqpjtAY robert-jordens-ed25519"
+    ];
+  };
+  harry = {
+    isNormalUser = true;
+    extraGroups = ["plugdev" "dialout" "wireshark"];
+    openssh.authorizedKeys.keys = [
+      "ecdsa-sha2-nistp384 AAAAE2VjZHNhLXNoYTItbmlzdHAzODQAAAAIbmlzdHAzODQAAABhBDcPNCgtdz8erFPRrAwCr4JrkeYXJUUvoRBgP0X2HlzJgDe1Inuo6sC6CGcO3IXbf4MwVA9XEp8BYPHARVeEHhufg/0wnIABLx2GcK99yxOLDUe4h/3YwtqvOcqHEsDx7w=="
+    ];
+  };
+  astro = {
+    isNormalUser = true;
+    extraGroups = ["plugdev" "dialout"];
+    openssh.authorizedKeys.keys = [
+      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGJJTSJdpDh82486uPiMhhyhnci4tScp5uUe7156MBC8 a"
+    ];
+    shell = pkgs.bashInteractive;
+  };
+  pca006132 = {
+    isNormalUser = true;
+    extraGroups = ["plugdev" "dialout"];
+    openssh.authorizedKeys.keys = [
+      "ecdsa-sha2-nistp384 AAAAE2VjZHNhLXNoYTItbmlzdHAzODQAAAAIbmlzdHAzODQAAABhBE/sPOOiw3843+rrcYV2pOVkffNc1xsOgnuCUmy1Fa2VF8x9kqmgQv61sxsuKRkKKoinvqrASxLkWVd6nkiiDuEISibEXs8r1BwuT05cS7RkEhCakSMZ6y/iqOtjt2bx+A=="
+    ];
+  };
+  occheung = {
+    isNormalUser = true;
+    extraGroups = ["plugdev" "dialout"];
+    openssh.authorizedKeys.keys = [
+      "ecdsa-sha2-nistp384 AAAAE2VjZHNhLXNoYTItbmlzdHAzODQAAAAIbmlzdHAzODQAAABhBPEvmWmxpFpMgp5fpjKud8ev0cyf/+X5fEpQt/YD/+u4mbvZYPE300DLqQ0h/qjgvaGMz1ndf4idYnRdy+plJEC/+hmlRW5NlcpAr3S/LYAisacgKToFVl+MlBo+emS9Ig=="
+    ];
+  };
+  dsleung = {
+    isNormalUser = true;
+    extraGroups = ["plugdev" "dialout"];
+    openssh.authorizedKeys.keys = [
+      "ecdsa-sha2-nistp384 AAAAE2VjZHNhLXNoYTItbmlzdHAzODQAAAAIbmlzdHAzODQAAABhBDbE7HzZKSwGbgRnzwrzCzb3gZKLSritwnEpHS4sa9oXJ5oLFkuFZOpPYDeiMlbUJ9jCk5FRmkLYIkrbz06SUr7P/eUjxu79ENi3RhfVu+ZrrPvgkhKvM/CiXvw3xCOu0w=="
+    ];
+  };
+}
--- a/nixops/desktop.nix
+++ b/nixops/desktop.nix
@ -0,0 +1,149 @@
+{ host }:
+
+{ config, pkgs, ... }:
+let
+  m-labs = import (fetchTarball https://nixbld.m-labs.hk/channel/custom/artiq/full/artiq-full/nixexprs.tar.xz) { inherit pkgs; };
+  pkgs-unstable = import (fetchTarball https://github.com/NixOS/nixpkgs/archive/master.tar.gz) {};
+in
+{
+  deployment.targetHost = host;
+
+  disabledModules = [ "security/pam.nix" ];
+  imports =
+    [
+      (./. + "/${host}-hardware-configuration.nix")
+      ./pam_p11
+    ];
+
+  networking.hostName = host;
+
+  time.timeZone = "Asia/Hong_Kong";
+
+  # List packages installed in system profile. To search, run:
+  # $ nix search wget
+  nixpkgs.config.allowUnfree = true;
+  environment.systemPackages = with pkgs; [
+    opensc yubikey-manager yubikey-manager-qt
+    wget vim gitAndTools.gitFull firefox chromium thunderbird hexchat
+    usbutils pciutils file lm_sensors audacious acpi
+    gimp imagemagick
+    (python3.withPackages(ps: with ps; [ numpy scipy matplotlib qtconsole regex ]))
+    mosh psmisc libreoffice-fresh
+    gtkwave telnet unzip zip gnupg
+    gnome3.gnome-tweaks
+    jq sublime3 rink qemu_kvm
+    tmux xc3sprog m-labs.openocd screen gdb minicom picocom tigervnc
+    emacs bat ripgrep
+    pkgs-unstable.rust-analyzer
+    (pkgs-unstable.vscode-with-extensions.override {
+      vscodeExtensions = [
+        pkgs-unstable.vscode-extensions.matklad.rust-analyzer
+      ];
+    })
+    (import ./fish-nix-shell)
+  ];
+  programs.wireshark.enable = true;
+
+  services.openssh.enable = true;
+  services.openssh.forwardX11 = true;
+  services.openssh.passwordAuthentication = false;
+  hardware.u2f.enable = true;
+  services.pcscd.enable = true;
+  programs.ssh.extraConfig =
+    ''
+    PKCS11Provider "${pkgs.opensc}/lib/opensc-pkcs11.so"
+    '';
+  programs.ssh.startAgent = true;
+  services.gnome3.gnome-keyring.enable = pkgs.lib.mkForce false;
+  programs.ssh.agentPKCS11Whitelist = "${pkgs.opensc}/lib/opensc-pkcs11.so";
+  security.pam.p11.enable = true;
+
+  # Enable CUPS to print documents.
+  services.printing = {
+    enable = true;
+    extraConf =
+      ''
+      Browsing Off
+      BrowseLocalProtocols none
+      '';
+    browsedConf =
+      ''
+      BrowseRemoteProtocols none
+      BrowseProtocols none
+      '';
+  };
+  services.avahi = {
+    enable = true;
+    nssmdns = true;
+  };
+
+  # Enable sound.
+  sound.enable = true;
+  hardware.pulseaudio = {
+    enable = true;
+    extraModules = [ pkgs.pulseaudio-modules-bt ];
+    package = pkgs.pulseaudioFull;
+  };
+
+  i18n.inputMethod = {
+    enabled = "fcitx";
+    fcitx.engines = with pkgs.fcitx-engines; [ table-extra m17n ];
+  };
+  fonts.fonts = [ pkgs.noto-fonts pkgs.noto-fonts-cjk pkgs.noto-fonts-emoji pkgs.noto-fonts-extra pkgs.emacs-all-the-icons-fonts ];
+
+  # Enable the X11 windowing system.
+  services.xserver.enable = true;
+  services.xserver.layout = "us";
+  services.xserver.xkbOptions = "eurosign:e";
+
+  # Enable touchpad support.
+  services.xserver.libinput.enable = true;
+
+  services.xserver.displayManager.gdm.enable = true;
+  services.xserver.displayManager.gdm.autoSuspend = false;
+  powerManagement.enable = false;
+  services.xserver.desktopManager.gnome3.enable = true;
+  environment.gnome3.excludePackages = [ pkgs.epiphany pkgs.gnome3.geary ];
+
+  hardware.bluetooth.enable = true;
+
+  programs.fish.enable = true;
+  programs.fish.promptInit = ''
+    fish-nix-shell --info-right | source
+  '';
+  users.mutableUsers = false;
+  users.defaultUserShell = pkgs.fish;
+  users.extraGroups.plugdev = { };
+  users.extraUsers = import ./common-users.nix { inherit pkgs; };
+  security.sudo.wheelNeedsPassword = false;
+  services.udev.packages = [ m-labs.openocd ];
+  services.udev.extraRules = ''
+# leaf maple
+SUBSYSTEM=="usb", ATTRS{idVendor}=="1eaf", ATTRS{idProduct}=="0003", MODE="0660", GROUP="plugdev"
+SUBSYSTEM=="usb", ATTRS{idVendor}=="1eaf", ATTRS{idProduct}=="0004", MODE="0660", GROUP="plugdev"
+# glasgow
+SUBSYSTEM=="usb", ATTRS{idVendor}=="20b7", ATTRS{idProduct}=="9db1", MODE="0660", GROUP="plugdev"
+# hackrf
+SUBSYSTEM=="usb", ATTRS{idVendor}=="1d50", ATTRS{idProduct}=="6089", MODE="0660", GROUP="plugdev"
+# bladerf
+SUBSYSTEM=="usb", ATTRS{idVendor}=="2cf0", ATTRS{idProduct}=="5250", MODE="0660", GROUP="plugdev"
+# personal measurement device
+SUBSYSTEM=="usb", ATTRS{idVendor}=="09db", ATTRS{idProduct}=="007a", MODE="0660", GROUP="plugdev"
+# saleae
+SUBSYSTEM=="usb", ATTRS{idVendor}=="0925", ATTRS{idProduct}=="3881", MODE="0660", GROUP="plugdev"
+# ocean optics
+SUBSYSTEM=="usb", ATTRS{idVendor}=="2457", ATTRS{idProduct}=="1002", MODE="0660", GROUP="plugdev"
+# yubikey
+SUBSYSTEM=="usb", ATTRS{idVendor}=="1050", ATTRS{idProduct}=="0116", MODE="0660", GROUP="plugdev"
+  '';
+
+  nix.binaryCachePublicKeys = ["nixbld.m-labs.hk-1:5aSRVA5b320xbNvu30tqxVPXpld73bhtOeH6uAjRyHc="];
+  nix.binaryCaches = ["https://nixbld.m-labs.hk" "https://cache.nixos.org"];
+  nix.sandboxPaths = ["/opt"];
+
+  # This value determines the NixOS release with which your system is to be
+  # compatible, in order to avoid breaking some software such as database
+  # servers. You should change this only after NixOS release notes say you
+  # should.
+  system.stateVersion = "19.03"; # Did you read the comment?
+}
--- a/nixops/fish-nix-shell/LICENSE
+++ b/nixops/fish-nix-shell/LICENSE
@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 haslersn
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
--- a/nixops/fish-nix-shell/README.md
+++ b/nixops/fish-nix-shell/README.md
@ -0,0 +1,50 @@
+# fish-nix-shell
+fish support for the *nix-shell* environment of the Nix package manager.
+
+## Installation
+
+### Installation in the user environment
+
+Execute
+
+```
+nix-env -if https://github.com/haslersn/fish-nix-shell/archive/master.tar.gz
+```
+
+and add the following to your *~/.config/fish/config.fish*. Create it if it doesn't exist.
+
+```
+fish-nix-shell --info-right | source
+```
+
+### System-wide installation
+
+Add the package to your */etc/nixos/configuration.nix*:
+
+```
+  environment.systemPackages = with pkgs; [
+    #
+    # Other packages here ...
+    #
+    (import (fetchGit "https://github.com/haslersn/fish-nix-shell"))
+  ];
+```
+
+and then execute: `sudo nixos-rebuild switch`
+
+If you want to configure it system-wide, also add:
+
+```
+  programs.fish.enable = true;
+  programs.fish.promptInit = ''
+    fish-nix-shell --info-right | source
+  '';
+```
+
+## Flags
+
+The `fish-nix-shell` command **optionally** takes the following flags:
+
+| Flag | Meaning |
+| - | - |
+| `--info-right` | While in a *fish-nix-shell*, display information about the loaded packages at the right.
--- a/nixops/fish-nix-shell/bin/fish-nix-shell
+++ b/nixops/fish-nix-shell/bin/fish-nix-shell
@ -0,0 +1,34 @@
+#!/bin/sh
+
+function init_fish () {
+                cat <<EOF
+
+# Overwrite the nix-shell command
+function nix-shell
+    fish-nix-shell-wrapper \$argv
+    set -gx FISH_NIX_SHELL_EXIT_STATUS \$status
+end
+EOF
+    for arg in "$@"; do
+        case "$arg" in
+            --info-right)
+                cat <<EOF
+
+# Print additional information inside a nix-shell environment
+function fish_right_prompt
+    nix-shell-info
+    set -e FISH_NIX_SHELL_EXIT_STATUS
+end
+EOF
+                ;;
+            *) exit 1;;
+        esac
+    done
+}
+
+cat <<EOF
+# If you see this output, you probably forgot to pipe this output into 'source':
+# fish-nix-shell $@ | source
+EOF
+
+init_fish "$@"
--- a/nixops/fish-nix-shell/bin/fish-nix-shell-wrapper
+++ b/nixops/fish-nix-shell/bin/fish-nix-shell-wrapper
@ -0,0 +1,22 @@
+#!/bin/sh
+fns () {
+    pkgs=$FISH_NIX_SHELL_PKGS
+    for arg in "$@"; do
+        if [[ $arg == -* ]]; then
+            pkg=
+            if [[ $arg == --pure ]] || [[ $arg == --command ]] || [[ $arg == --run ]]; then
+                command nix-shell $@
+                return
+            elif [[ $arg == -p ]] || [[ $arg == --packages ]]; then
+                pkg=1
+            fi
+        elif [[ $pkg == 1 ]]; then
+            pkgs+=" "$arg
+        fi
+    done
+    if [[ -n $name ]] && [[ $name != shell ]]; then
+        pkgs+=" "$name
+    fi
+    env FISH_NIX_SHELL_PKGS="$pkgs" nix-shell "$@" --command fish
+}
+fns "$@"
--- a/nixops/fish-nix-shell/bin/nix-shell-info
+++ b/nixops/fish-nix-shell/bin/nix-shell-info
@ -0,0 +1,21 @@
+#!/bin/sh
+if [[ $IN_NIX_SHELL != "" ]]; then
+    printf "\033[1;32m"
+    output=$(echo $FISH_NIX_SHELL_PKGS | xargs)
+    if [[ -n $name ]] && [[ $name != shell ]]; then
+        output+=" "$name
+    fi
+    if [[ -n $output ]]; then
+        output=$(echo $output $additional_pkgs | tr ' ' '\n' | sort -u | tr '\n' ' ' | xargs)
+        printf "$output "
+    else
+        printf "[unknown nix-shell] "
+    fi
+    printf "\033[0m"
+elif [[ $FISH_NIX_SHELL_EXIT_STATUS ]]; then
+    if [[ $FISH_NIX_SHELL_EXIT_STATUS == 0 ]]; then
+      printf "\033[1;36mexited nix-shell \033[0m"
+    else
+      printf "\033[1;31mERROR \033[0m"
+    fi
+fi
--- a/nixops/fish-nix-shell/default.nix
+++ b/nixops/fish-nix-shell/default.nix
@ -0,0 +1,16 @@
+with import <nixpkgs> {}; stdenv.mkDerivation rec {
+  name = "fish-nix-shell";
+  src = fetchGit "https://github.com/haslersn/fish-nix-shell";
+  nativeBuildInputs = [ makeWrapper ];
+  installPhase = ''
+    mkdir -p $out
+    cp LICENSE $out
+    cp -r bin $out
+    wrapProgram $out/bin/fish-nix-shell
+    wrapProgram $out/bin/fish-nix-shell-wrapper --prefix PATH ":" ${fish}/bin
+    wrapProgram $out/bin/nix-shell-info
+  '';
+  meta.description = "fish support for the nix-shell environment of the Nix package manager.";
+  meta.license = "MIT";
+  meta.homepage = https://github.com/haslersn/fish-nix-shell;
+}
--- a/nixops/hera-hardware-configuration.nix
+++ b/nixops/hera-hardware-configuration.nix
@ -0,0 +1,33 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [ <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
+    ];
+
+  boot.initrd.availableKernelModules = [ "xhci_pci" "ahci" "nvme" "usbhid" "usb_storage" "sd_mod" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" =
+    { device = "/dev/disk/by-uuid/a86f2eff-c873-4af1-bb80-a903383b9c8c";
+      fsType = "ext4";
+    };
+
+  fileSystems."/boot" =
+    { device = "/dev/disk/by-uuid/8C30-F6DC";
+      fsType = "vfat";
+    };
+
+  swapDevices = [ ];
+
+  nix.maxJobs = lib.mkDefault 16;
+  powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+}
--- a/nixops/hestia-hardware-configuration.nix
+++ b/nixops/hestia-hardware-configuration.nix
@ -0,0 +1,33 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [ <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
+    ];
+
+  boot.initrd.availableKernelModules = [ "xhci_pci" "ahci" "nvme" "usbhid" "usb_storage" "sd_mod" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" =
+    { device = "/dev/disk/by-uuid/2fe28058-4186-4e65-9d3d-f7ec5dffc171";
+      fsType = "ext4";
+    };
+
+  fileSystems."/boot" =
+    { device = "/dev/disk/by-uuid/E085-5F21";
+      fsType = "vfat";
+    };
+
+  swapDevices = [ ];
+
+  nix.maxJobs = lib.mkDefault 16;
+  powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+}
--- a/nixops/juno-hardware-configuration.nix
+++ b/nixops/juno-hardware-configuration.nix
@ -0,0 +1,30 @@
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [ <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
+    ];
+
+  boot.initrd.availableKernelModules = [ "xhci_pci" "ehci_pci" "ahci" "usbhid" "usb_storage" "sd_mod" "sr_mod" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" =
+    { device = "/dev/disk/by-uuid/62a38d9c-452c-4648-be12-6131e95b8276";
+      fsType = "ext4";
+    };
+
+  fileSystems."/boot" =
+    { device = "/dev/disk/by-uuid/88F6-46F2";
+      fsType = "vfat";
+    };
+
+  swapDevices = [ ];
+
+  nix.maxJobs = lib.mkDefault 8;
+  powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+}
--- a/nixops/light.nix
+++ b/nixops/light.nix
@ -0,0 +1,112 @@
+{ host }:
+
+{ config, pkgs, ... }:
+{
+  deployment.targetHost = host;
+
+  disabledModules = [ "security/pam.nix" ];
+  imports =
+    [
+      (./. + "/${host}-hardware-configuration.nix")
+      ./pam_p11
+    ];
+
+  networking.hostName = host;
+
+  time.timeZone = "Asia/Hong_Kong";
+
+  # List packages installed in system profile. To search, run:
+  # $ nix search wget
+  documentation.enable = false;
+  nixpkgs.config.allowUnfree = true;
+  environment.systemPackages = with pkgs; [
+    opensc
+    wget vim git firefox usbutils pciutils file lm_sensors acpi
+    gimp imagemagick
+    (python3.withPackages(ps: with ps; [ numpy scipy ]))
+    psmisc
+    telnet unzip zip gnupg
+    sublime3 rink
+    tmux screen tigervnc
+    (import ./fish-nix-shell)
+  ];
+  programs.wireshark.enable = true;
+
+  services.openssh.enable = true;
+  services.openssh.forwardX11 = true;
+  services.openssh.passwordAuthentication = false;
+  hardware.u2f.enable = true;
+  services.pcscd.enable = true;
+  programs.ssh.extraConfig =
+    ''
+    PKCS11Provider "${pkgs.opensc}/lib/opensc-pkcs11.so"
+    '';
+  programs.ssh.startAgent = true;
+  programs.ssh.agentPKCS11Whitelist = "${pkgs.opensc}/lib/opensc-pkcs11.so";
+  security.pam.p11.enable = true;
+
+  # Enable CUPS to print documents.
+  services.printing = {
+    enable = true;
+    extraConf =
+      ''
+      Browsing Off
+      BrowseLocalProtocols none
+      '';
+    browsedConf =
+      ''
+      BrowseRemoteProtocols none
+      BrowseProtocols none
+      '';
+  };
+  services.avahi = {
+    enable = true;
+    nssmdns = true;
+  };
+
+  # Enable sound.
+  sound.enable = true;
+  hardware.pulseaudio = {
+    enable = true;
+    extraModules = [ pkgs.pulseaudio-modules-bt ];
+    package = pkgs.pulseaudioFull;
+  };
+
+  i18n.inputMethod = {
+    enabled = "fcitx";
+    fcitx.engines = with pkgs.fcitx-engines; [ table-extra m17n ];
+  };
+  fonts.fonts = [ pkgs.noto-fonts pkgs.noto-fonts-cjk pkgs.noto-fonts-emoji pkgs.noto-fonts-extra ];
+
+  # Enable the X11 windowing system.
+  services.xserver.enable = true;
+  services.xserver.layout = "us";
+  services.xserver.xkbOptions = "eurosign:e";
+
+  # Enable touchpad support.
+  services.xserver.libinput.enable = true;
+
+  services.xserver.displayManager.lightdm.enable = true;
+  services.xserver.desktopManager.xfce.enable = true;
+
+  programs.fish.enable = true;
+  programs.fish.promptInit = ''
+    fish-nix-shell --info-right | source
+  '';
+  users.mutableUsers = false;
+  users.defaultUserShell = pkgs.fish;
+  users.extraGroups.plugdev = { };
+  users.extraUsers = import ./common-users.nix { inherit pkgs; };
+  
+  security.sudo.wheelNeedsPassword = false;
+
+  nix.binaryCachePublicKeys = ["nixbld.m-labs.hk-1:5aSRVA5b320xbNvu30tqxVPXpld73bhtOeH6uAjRyHc="];
+  nix.binaryCaches = ["https://nixbld.m-labs.hk" "https://cache.nixos.org"];
+  nix.sandboxPaths = ["/opt"];
+
+  # This value determines the NixOS release with which your system is to be
+  # compatible, in order to avoid breaking some software such as database
+  # servers. You should change this only after NixOS release notes say you
+  # should.
+  system.stateVersion = "19.03"; # Did you read the comment?
+}
--- a/nixops/nixops.nix
+++ b/nixops/nixops.nix
@ -0,0 +1,13 @@
+{
+  rpi-1 = import ./rpi.nix { host = "rpi-1"; rpi4 = false; };
+  rpi-2 = import ./rpi.nix { host = "rpi-2"; rpi4 = false; };
+  rpi-3 = import ./rpi.nix { host = "rpi-3"; rpi4 = true; };
+  rpi-4 = import ./rpi.nix { host = "rpi-4"; rpi4 = true; };
+  rpi-5 = import ./rpi.nix { host = "rpi-5"; rpi4 = true; };
+  juno = import ./desktop.nix { host = "juno"; };
+  zeus = import ./desktop.nix { host = "zeus"; };
+  hera = import ./desktop.nix { host = "hera"; };
+  hestia = import ./desktop.nix { host = "hestia"; };
+  chiron = import ./desktop.nix { host = "chiron"; };
+  cnc = import ./light.nix { host = "cnc"; };
+}
--- a/nixops/pam_p11/default.nix
+++ b/nixops/pam_p11/default.nix
@ -0,0 +1,843 @@
+# This module provides configuration for the PAM (Pluggable
+# Authentication Modules) system.
+
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  pam_p11 = pkgs.callPackage ./pam_p11.nix {};
+
+  parentConfig = config;
+
+  pamOpts = { config, name, ... }: let cfg = config; in let config = parentConfig; in {
+
+    options = {
+
+      name = mkOption {
+        example = "sshd";
+        type = types.str;
+        description = "Name of the PAM service.";
+      };
+
+      unixAuth = mkOption {
+        default = true;
+        type = types.bool;
+        description = ''
+          Whether users can log in with passwords defined in
+          <filename>/etc/shadow</filename>.
+        '';
+      };
+
+      rootOK = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          If set, root doesn't need to authenticate (e.g. for the
+          <command>useradd</command> service).
+        '';
+      };
+
+      p11Auth = mkOption {
+        default = config.security.pam.p11.enable;
+        type = types.bool;
+        description = ''
+          If set, keys listed in
+          <filename>~/.ssh/authorized_keys</filename> and
+          <filename>~/.eid/authorized_certificates</filename>
+          can be used to log in with the associated PKCS#11 tokens.
+        '';
+      };
+
+      u2fAuth = mkOption {
+        default = config.security.pam.u2f.enable;
+        type = types.bool;
+        description = ''
+          If set, users listed in
+          <filename>$XDG_CONFIG_HOME/Yubico/u2f_keys</filename> (or
+          <filename>$HOME/.config/Yubico/u2f_keys</filename> if XDG variable is
+          not set) are able to log in with the associated U2F key. Path can be
+          changed using <option>security.pam.u2f.authFile</option> option.
+        '';
+      };
+
+      yubicoAuth = mkOption {
+        default = config.security.pam.yubico.enable;
+        type = types.bool;
+        description = ''
+          If set, users listed in
+          <filename>~/.yubico/authorized_yubikeys</filename>
+          are able to log in with the associated Yubikey tokens.
+        '';
+      };
+
+      googleAuthenticator = {
+        enable = mkOption {
+          default = false;
+          type = types.bool;
+          description = ''
+            If set, users with enabled Google Authenticator (created
+            <filename>~/.google_authenticator</filename>) will be required
+            to provide Google Authenticator token to log in.
+          '';
+        };
+      };
+
+      usbAuth = mkOption {
+        default = config.security.pam.usb.enable;
+        type = types.bool;
+        description = ''
+          If set, users listed in
+          <filename>/etc/pamusb.conf</filename> are able to log in
+          with the associated USB key.
+        '';
+      };
+
+      otpwAuth = mkOption {
+        default = config.security.pam.enableOTPW;
+        type = types.bool;
+        description = ''
+          If set, the OTPW system will be used (if
+          <filename>~/.otpw</filename> exists).
+        '';
+      };
+
+      googleOsLoginAccountVerification = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          If set, will use the Google OS Login PAM modules
+          (<literal>pam_oslogin_login</literal>,
+          <literal>pam_oslogin_admin</literal>) to verify possible OS Login
+          users and set sudoers configuration accordingly.
+          This only makes sense to enable for the <literal>sshd</literal> PAM
+          service.
+        '';
+      };
+
+      googleOsLoginAuthentication = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          If set, will use the <literal>pam_oslogin_login</literal>'s user
+          authentication methods to authenticate users using 2FA.
+          This only makes sense to enable for the <literal>sshd</literal> PAM
+          service.
+        '';
+      };
+
+      fprintAuth = mkOption {
+        default = config.services.fprintd.enable;
+        type = types.bool;
+        description = ''
+          If set, fingerprint reader will be used (if exists and
+          your fingerprints are enrolled).
+        '';
+      };
+
+      oathAuth = mkOption {
+        default = config.security.pam.oath.enable;
+        type = types.bool;
+        description = ''
+          If set, the OATH Toolkit will be used.
+        '';
+      };
+
+      sshAgentAuth = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          If set, the calling user's SSH agent is used to authenticate
+          against the keys in the calling user's
+          <filename>~/.ssh/authorized_keys</filename>.  This is useful
+          for <command>sudo</command> on password-less remote systems.
+        '';
+      };
+
+      duoSecurity = {
+        enable = mkOption {
+          default = false;
+          type = types.bool;
+          description = ''
+            If set, use the Duo Security pam module
+            <literal>pam_duo</literal> for authentication.  Requires
+            configuration of <option>security.duosec</option> options.
+          '';
+        };
+      };
+
+      startSession = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          If set, the service will register a new session with
+          systemd's login manager.  For local sessions, this will give
+          the user access to audio devices, CD-ROM drives.  In the
+          default PolicyKit configuration, it also allows the user to
+          reboot the system.
+        '';
+      };
+
+      setEnvironment = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether the service should set the environment variables
+          listed in <option>environment.sessionVariables</option>
+          using <literal>pam_env.so</literal>.
+        '';
+      };
+
+      setLoginUid = mkOption {
+        type = types.bool;
+        description = ''
+          Set the login uid of the process
+          (<filename>/proc/self/loginuid</filename>) for auditing
+          purposes.  The login uid is only set by ‘entry points’ like
+          <command>login</command> and <command>sshd</command>, not by
+          commands like <command>sudo</command>.
+        '';
+      };
+
+      forwardXAuth = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Whether X authentication keys should be passed from the
+          calling user to the target user (e.g. for
+          <command>su</command>)
+        '';
+      };
+
+      pamMount = mkOption {
+        default = config.security.pam.mount.enable;
+        type = types.bool;
+        description = ''
+          Enable PAM mount (pam_mount) system to mount fileystems on user login.
+        '';
+      };
+
+      allowNullPassword = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Whether to allow logging into accounts that have no password
+          set (i.e., have an empty password field in
+          <filename>/etc/passwd</filename> or
+          <filename>/etc/group</filename>).  This does not enable
+          logging into disabled accounts (i.e., that have the password
+          field set to <literal>!</literal>).  Note that regardless of
+          what the pam_unix documentation says, accounts with hashed
+          empty passwords are always allowed to log in.
+        '';
+      };
+
+      nodelay = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Wheather the delay after typing a wrong password should be disabled.
+        '';
+      };
+
+      requireWheel = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Whether to permit root access only to members of group wheel.
+        '';
+      };
+
+      limits = mkOption {
+        description = ''
+          Attribute set describing resource limits.  Defaults to the
+          value of <option>security.pam.loginLimits</option>.
+        '';
+      };
+
+      showMotd = mkOption {
+        default = false;
+        type = types.bool;
+        description = "Whether to show the message of the day.";
+      };
+
+      makeHomeDir = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Whether to try to create home directories for users
+          with <literal>$HOME</literal>s pointing to nonexistent
+          locations on session login.
+        '';
+      };
+
+      updateWtmp = mkOption {
+        default = false;
+        type = types.bool;
+        description = "Whether to update <filename>/var/log/wtmp</filename>.";
+      };
+
+      logFailures = mkOption {
+        default = false;
+        type = types.bool;
+        description = "Whether to log authentication failures in <filename>/var/log/faillog</filename>.";
+      };
+
+      enableAppArmor = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Enable support for attaching AppArmor profiles at the
+          user/group level, e.g., as part of a role based access
+          control scheme.
+        '';
+      };
+
+      enableKwallet = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          If enabled, pam_wallet will attempt to automatically unlock the
+          user's default KDE wallet upon login. If the user has no wallet named
+          "kdewallet", or the login password does not match their wallet
+          password, KDE will prompt separately after login.
+        '';
+      };
+      sssdStrictAccess = mkOption {
+        default = false;
+        type = types.bool;
+        description = "enforce sssd access control";
+      };
+
+      enableGnomeKeyring = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          If enabled, pam_gnome_keyring will attempt to automatically unlock the
+          user's default Gnome keyring upon login. If the user login password does
+          not match their keyring password, Gnome Keyring will prompt separately
+          after login.
+        '';
+      };
+
+      text = mkOption {
+        type = types.nullOr types.lines;
+        description = "Contents of the PAM service file.";
+      };
+
+    };
+
+    config = {
+      name = mkDefault name;
+      setLoginUid = mkDefault cfg.startSession;
+      limits = mkDefault config.security.pam.loginLimits;
+
+      # !!! TODO: move the LDAP stuff to the LDAP module, and the
+      # Samba stuff to the Samba module.  This requires that the PAM
+      # module provides the right hooks.
+      text = mkDefault
+        (''
+          # Account management.
+          account required pam_unix.so
+          ${optionalString use_ldap
+              "account sufficient ${pam_ldap}/lib/security/pam_ldap.so"}
+          ${optionalString (config.services.sssd.enable && cfg.sssdStrictAccess==false)
+              "account sufficient ${pkgs.sssd}/lib/security/pam_sss.so"}
+          ${optionalString (config.services.sssd.enable && cfg.sssdStrictAccess)
+              "account [default=bad success=ok user_unknown=ignore] ${pkgs.sssd}/lib/security/pam_sss.so"}
+          ${optionalString config.krb5.enable
+              "account sufficient ${pam_krb5}/lib/security/pam_krb5.so"}
+          ${optionalString cfg.googleOsLoginAccountVerification ''
+            account [success=ok ignore=ignore default=die] ${pkgs.google-compute-engine-oslogin}/lib/pam_oslogin_login.so
+            account [success=ok default=ignore] ${pkgs.google-compute-engine-oslogin}/lib/pam_oslogin_admin.so
+          ''}
+
+          # Authentication management.
+          ${optionalString cfg.googleOsLoginAuthentication
+              "auth [success=done perm_denied=bad default=ignore] ${pkgs.google-compute-engine-oslogin}/lib/pam_oslogin_login.so"}
+          ${optionalString cfg.rootOK
+              "auth sufficient pam_rootok.so"}
+          ${optionalString cfg.requireWheel
+              "auth required pam_wheel.so use_uid"}
+          ${optionalString cfg.logFailures
+              "auth required pam_tally.so"}
+          ${optionalString (config.security.pam.enableSSHAgentAuth && cfg.sshAgentAuth)
+              "auth sufficient ${pkgs.pam_ssh_agent_auth}/libexec/pam_ssh_agent_auth.so file=~/.ssh/authorized_keys:~/.ssh/authorized_keys2:/etc/ssh/authorized_keys.d/%u"}
+          ${optionalString cfg.fprintAuth
+              "auth sufficient ${pkgs.fprintd}/lib/security/pam_fprintd.so"}
+          ${let p11 = config.security.pam.p11; in optionalString cfg.p11Auth
+              "auth ${p11.control} ${pam_p11}/lib/security/pam_p11.so ${pkgs.opensc}/lib/opensc-pkcs11.so"}
+          ${let u2f = config.security.pam.u2f; in optionalString cfg.u2fAuth
+              "auth ${u2f.control} ${pkgs.pam_u2f}/lib/security/pam_u2f.so ${optionalString u2f.debug "debug"} ${optionalString (u2f.authFile != null) "authfile=${u2f.authFile}"} ${optionalString u2f.interactive "interactive"} ${optionalString u2f.cue "cue"}"}
+          ${optionalString cfg.usbAuth
+              "auth sufficient ${pkgs.pam_usb}/lib/security/pam_usb.so"}
+          ${let oath = config.security.pam.oath; in optionalString cfg.oathAuth
+              "auth requisite ${pkgs.oathToolkit}/lib/security/pam_oath.so window=${toString oath.window} usersfile=${toString oath.usersFile} digits=${toString oath.digits}"}
+          ${let yubi = config.security.pam.yubico; in optionalString cfg.yubicoAuth
+              "auth ${yubi.control} ${pkgs.yubico-pam}/lib/security/pam_yubico.so mode=${toString yubi.mode} ${optionalString (yubi.mode == "client") "id=${toString yubi.id}"} ${optionalString yubi.debug "debug"}"}
+        '' +
+          # Modules in this block require having the password set in PAM_AUTHTOK.
+          # pam_unix is marked as 'sufficient' on NixOS which means nothing will run
+          # after it succeeds. Certain modules need to run after pam_unix
+          # prompts the user for password so we run it once with 'required' at an
+          # earlier point and it will run again with 'sufficient' further down.
+          # We use try_first_pass the second time to avoid prompting password twice
+          (optionalString (cfg.unixAuth &&
+          (config.security.pam.enableEcryptfs
+            || cfg.pamMount
+            || cfg.enableKwallet
+            || cfg.enableGnomeKeyring
+            || cfg.googleAuthenticator.enable
+            || cfg.duoSecurity.enable)) ''
+              auth required pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} ${optionalString cfg.nodelay "nodelay"} likeauth
+              ${optionalString config.security.pam.enableEcryptfs
+                "auth optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so unwrap"}
+              ${optionalString cfg.pamMount
+                "auth optional ${pkgs.pam_mount}/lib/security/pam_mount.so"}
+              ${optionalString cfg.enableKwallet
+                ("auth optional ${pkgs.plasma5.kwallet-pam}/lib/security/pam_kwallet5.so" +
+                 " kwalletd=${pkgs.libsForQt5.kwallet.bin}/bin/kwalletd5")}
+              ${optionalString cfg.enableGnomeKeyring
+                "auth optional ${pkgs.gnome3.gnome-keyring}/lib/security/pam_gnome_keyring.so"}
+              ${optionalString cfg.googleAuthenticator.enable
+                "auth required ${pkgs.googleAuthenticator}/lib/security/pam_google_authenticator.so no_increment_hotp"}
+              ${optionalString cfg.duoSecurity.enable
+                "auth required ${pkgs.duo-unix}/lib/security/pam_duo.so"}
+            '') + ''
+          ${optionalString cfg.unixAuth
+              "auth sufficient pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} ${optionalString cfg.nodelay "nodelay"} likeauth try_first_pass"}
+          ${optionalString cfg.otpwAuth
+              "auth sufficient ${pkgs.otpw}/lib/security/pam_otpw.so"}
+          ${optionalString use_ldap
+              "auth sufficient ${pam_ldap}/lib/security/pam_ldap.so use_first_pass"}
+          ${optionalString config.services.sssd.enable
+              "auth sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_first_pass"}
+          ${optionalString config.krb5.enable ''
+            auth [default=ignore success=1 service_err=reset] ${pam_krb5}/lib/security/pam_krb5.so use_first_pass
+            auth [default=die success=done] ${pam_ccreds}/lib/security/pam_ccreds.so action=validate use_first_pass
+            auth sufficient ${pam_ccreds}/lib/security/pam_ccreds.so action=store use_first_pass
+          ''}
+          auth required pam_deny.so
+
+          # Password management.
+          password sufficient pam_unix.so nullok sha512
+          ${optionalString config.security.pam.enableEcryptfs
+              "password optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so"}
+          ${optionalString cfg.pamMount
+              "password optional ${pkgs.pam_mount}/lib/security/pam_mount.so"}
+          ${optionalString use_ldap
+              "password sufficient ${pam_ldap}/lib/security/pam_ldap.so"}
+          ${optionalString config.services.sssd.enable
+              "password sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_authtok"}
+          ${optionalString config.krb5.enable
+              "password sufficient ${pam_krb5}/lib/security/pam_krb5.so use_first_pass"}
+          ${optionalString config.services.samba.syncPasswordsByPam
+              "password optional ${pkgs.samba}/lib/security/pam_smbpass.so nullok use_authtok try_first_pass"}
+          ${optionalString cfg.enableGnomeKeyring
+              "password optional ${pkgs.gnome3.gnome-keyring}/lib/security/pam_gnome_keyring.so use_authtok"}
+
+          # Session management.
+          ${optionalString cfg.setEnvironment ''
+            session required pam_env.so conffile=${config.system.build.pamEnvironment} readenv=0
+          ''}
+          session required pam_unix.so
+          ${optionalString cfg.setLoginUid
+              "session ${
+                if config.boot.isContainer then "optional" else "required"
+              } pam_loginuid.so"}
+          ${optionalString cfg.makeHomeDir
+              "session required ${pkgs.pam}/lib/security/pam_mkhomedir.so silent skel=${config.security.pam.makeHomeDir.skelDirectory} umask=0022"}
+          ${optionalString cfg.updateWtmp
+              "session required ${pkgs.pam}/lib/security/pam_lastlog.so silent"}
+          ${optionalString config.security.pam.enableEcryptfs
+              "session optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so"}
+          ${optionalString use_ldap
+              "session optional ${pam_ldap}/lib/security/pam_ldap.so"}
+          ${optionalString config.services.sssd.enable
+              "session optional ${pkgs.sssd}/lib/security/pam_sss.so"}
+          ${optionalString config.krb5.enable
+              "session optional ${pam_krb5}/lib/security/pam_krb5.so"}
+          ${optionalString cfg.otpwAuth
+              "session optional ${pkgs.otpw}/lib/security/pam_otpw.so"}
+          ${optionalString cfg.startSession
+              "session optional ${pkgs.systemd}/lib/security/pam_systemd.so"}
+          ${optionalString cfg.forwardXAuth
+              "session optional pam_xauth.so xauthpath=${pkgs.xorg.xauth}/bin/xauth systemuser=99"}
+          ${optionalString (cfg.limits != [])
+              "session required ${pkgs.pam}/lib/security/pam_limits.so conf=${makeLimitsConf cfg.limits}"}
+          ${optionalString (cfg.showMotd && config.users.motd != null)
+              "session optional ${pkgs.pam}/lib/security/pam_motd.so motd=${motd}"}
+          ${optionalString cfg.pamMount
+              "session optional ${pkgs.pam_mount}/lib/security/pam_mount.so"}
+          ${optionalString (cfg.enableAppArmor && config.security.apparmor.enable)
+              "session optional ${pkgs.apparmor-pam}/lib/security/pam_apparmor.so order=user,group,default debug"}
+          ${optionalString (cfg.enableKwallet)
+              ("session optional ${pkgs.plasma5.kwallet-pam}/lib/security/pam_kwallet5.so" +
+               " kwalletd=${pkgs.libsForQt5.kwallet.bin}/bin/kwalletd5")}
+          ${optionalString (cfg.enableGnomeKeyring)
+              "session optional ${pkgs.gnome3.gnome-keyring}/lib/security/pam_gnome_keyring.so auto_start"}
+          ${optionalString (config.virtualisation.lxc.lxcfs.enable)
+               "session optional ${pkgs.lxc}/lib/security/pam_cgfs.so -c all"}
+        '');
+    };
+
+  };
+
+
+  inherit (pkgs) pam_krb5 pam_ccreds;
+
+  use_ldap = (config.users.ldap.enable && config.users.ldap.loginPam);
+  pam_ldap = if config.users.ldap.daemon.enable then pkgs.nss_pam_ldapd else pkgs.pam_ldap;
+
+  # Create a limits.conf(5) file.
+  makeLimitsConf = limits:
+    pkgs.writeText "limits.conf"
+       (concatMapStrings ({ domain, type, item, value }:
+         "${domain} ${type} ${item} ${toString value}\n")
+         limits);
+
+  motd = pkgs.writeText "motd" config.users.motd;
+
+  makePAMService = name: service:
+    { name = "pam.d/${name}";
+      value.source = pkgs.writeText "${name}.pam" service.text;
+    };
+
+in
+
+{
+
+  imports = [
+    (mkRenamedOptionModule [ "security" "pam" "enableU2F" ] [ "security" "pam" "u2f" "enable" ])
+  ];
+
+  ###### interface
+
+  options = {
+
+    security.pam.loginLimits = mkOption {
+      default = [];
+      example =
+        [ { domain = "ftp";
+            type   = "hard";
+            item   = "nproc";
+            value  = "0";
+          }
+          { domain = "@student";
+            type   = "-";
+            item   = "maxlogins";
+            value  = "4";
+          }
+       ];
+
+     description =
+       '' Define resource limits that should apply to users or groups.
+          Each item in the list should be an attribute set with a
+          <varname>domain</varname>, <varname>type</varname>,
+          <varname>item</varname>, and <varname>value</varname>
+          attribute.  The syntax and semantics of these attributes
+          must be that described in the limits.conf(5) man page.
+
+          Note that these limits do not apply to systemd services,
+          whose limits can be changed via <option>systemd.extraConfig</option>
+          instead.
+       '';
+    };
+
+    security.pam.services = mkOption {
+      default = [];
+      type = with types; loaOf (submodule pamOpts);
+      description =
+        ''
+          This option defines the PAM services.  A service typically
+          corresponds to a program that uses PAM,
+          e.g. <command>login</command> or <command>passwd</command>.
+          Each attribute of this set defines a PAM service, with the attribute name
+          defining the name of the service.
+        '';
+    };
+
+    security.pam.makeHomeDir.skelDirectory = mkOption {
+      type = types.str;
+      default = "/var/empty";
+      example =  "/etc/skel";
+      description = ''
+        Path to skeleton directory whose contents are copied to home
+        directories newly created by <literal>pam_mkhomedir</literal>.
+      '';
+    };
+
+    security.pam.enableSSHAgentAuth = mkOption {
+      type = types.bool;
+      default = false;
+      description =
+        ''
+          Enable sudo logins if the user's SSH agent provides a key
+          present in <filename>~/.ssh/authorized_keys</filename>.
+          This allows machines to exclusively use SSH keys instead of
+          passwords.
+        '';
+    };
+
+    security.pam.enableOTPW = mkEnableOption "the OTPW (one-time password) PAM module";
+
+    security.pam.p11 = {
+      enable = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Enables P11 PAM (<literal>pam_p11</literal>) module.
+
+          If set, users can log in with SSH keys and PKCS#11 tokens.
+
+          More information can be found <link
+          xlink:href="https://github.com/OpenSC/pam_p11">here</link>.
+        '';
+      };
+
+      control = mkOption {
+        default = "sufficient";
+        type = types.enum [ "required" "requisite" "sufficient" "optional" ];
+        description = ''
+          This option sets pam "control".
+          If you want to have multi factor authentication, use "required".
+          If you want to use the PKCS#11 device instead of the regular password,
+          use "sufficient".
+
+          Read
+          <citerefentry>
+            <refentrytitle>pam.conf</refentrytitle>
+            <manvolnum>5</manvolnum>
+          </citerefentry>
+          for better understanding of this option.
+        '';
+      };
+    };
+
+    security.pam.u2f = {
+      enable = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Enables U2F PAM (<literal>pam-u2f</literal>) module.
+
+          If set, users listed in
+          <filename>$XDG_CONFIG_HOME/Yubico/u2f_keys</filename> (or
+          <filename>$HOME/.config/Yubico/u2f_keys</filename> if XDG variable is
+          not set) are able to log in with the associated U2F key. The path can
+          be changed using <option>security.pam.u2f.authFile</option> option.
+
+          File format is:
+          <literal>username:first_keyHandle,first_public_key: second_keyHandle,second_public_key</literal>
+          This file can be generated using <command>pamu2fcfg</command> command.
+
+          More information can be found <link
+          xlink:href="https://developers.yubico.com/pam-u2f/">here</link>.
+        '';
+      };
+
+      authFile = mkOption {
+        default = null;
+        type = with types; nullOr path;
+        description = ''
+          By default <literal>pam-u2f</literal> module reads the keys from
+          <filename>$XDG_CONFIG_HOME/Yubico/u2f_keys</filename> (or
+          <filename>$HOME/.config/Yubico/u2f_keys</filename> if XDG variable is
+          not set).
+
+          If you want to change auth file locations or centralize database (for
+          example use <filename>/etc/u2f-mappings</filename>) you can set this
+          option.
+
+          File format is:
+          <literal>username:first_keyHandle,first_public_key: second_keyHandle,second_public_key</literal>
+          This file can be generated using <command>pamu2fcfg</command> command.
+
+          More information can be found <link
+          xlink:href="https://developers.yubico.com/pam-u2f/">here</link>.
+        '';
+      };
+
+      control = mkOption {
+        default = "sufficient";
+        type = types.enum [ "required" "requisite" "sufficient" "optional" ];
+        description = ''
+          This option sets pam "control".
+          If you want to have multi factor authentication, use "required".
+          If you want to use U2F device instead of regular password, use "sufficient".
+
+          Read
+          <citerefentry>
+            <refentrytitle>pam.conf</refentrytitle>
+            <manvolnum>5</manvolnum>
+          </citerefentry>
+          for better understanding of this option.
+        '';
+      };
+
+      debug = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Debug output to stderr.
+        '';
+      };
+
+      interactive = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Set to prompt a message and wait before testing the presence of a U2F device.
+          Recommended if your device doesn’t have a tactile trigger.
+        '';
+      };
+
+      cue = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          By default <literal>pam-u2f</literal> module does not inform user
+          that he needs to use the u2f device, it just waits without a prompt.
+
+          If you set this option to <literal>true</literal>,
+          <literal>cue</literal> option is added to <literal>pam-u2f</literal>
+          module and reminder message will be displayed.
+        '';
+      };
+    };
+
+    security.pam.yubico = {
+      enable = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Enables Yubico PAM (<literal>yubico-pam</literal>) module.
+
+          If set, users listed in
+          <filename>~/.yubico/authorized_yubikeys</filename>
+          are able to log in with the associated Yubikey tokens.
+
+          The file must have only one line:
+          <literal>username:yubikey_token_id1:yubikey_token_id2</literal>
+          More information can be found <link
+          xlink:href="https://developers.yubico.com/yubico-pam/">here</link>.
+        '';
+      };
+      control = mkOption {
+        default = "sufficient";
+        type = types.enum [ "required" "requisite" "sufficient" "optional" ];
+        description = ''
+          This option sets pam "control".
+          If you want to have multi factor authentication, use "required".
+          If you want to use Yubikey instead of regular password, use "sufficient".
+
+          Read
+          <citerefentry>
+            <refentrytitle>pam.conf</refentrytitle>
+            <manvolnum>5</manvolnum>
+          </citerefentry>
+          for better understanding of this option.
+        '';
+      };
+      id = mkOption {
+        example = "42";
+        type = types.str;
+        description = "client id";
+      };
+
+      debug = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Debug output to stderr.
+        '';
+      };
+      mode = mkOption {
+        default = "client";
+        type = types.enum [ "client" "challenge-response" ];
+        description = ''
+          Mode of operation.
+
+          Use "client" for online validation with a YubiKey validation service such as
+          the YubiCloud.
+
+          Use "challenge-response" for offline validation using YubiKeys with HMAC-SHA-1
+          Challenge-Response configurations. See the man-page ykpamcfg(1) for further
+          details on how to configure offline Challenge-Response validation.
+
+          More information can be found <link
+          xlink:href="https://developers.yubico.com/yubico-pam/Authentication_Using_Challenge-Response.html">here</link>.
+        '';
+      };
+    };
+
+    security.pam.enableEcryptfs = mkEnableOption "eCryptfs PAM module (mounting ecryptfs home directory on login)";
+
+    users.motd = mkOption {
+      default = null;
+      example = "Today is Sweetmorn, the 4th day of The Aftermath in the YOLD 3178.";
+      type = types.nullOr types.lines;
+      description = "Message of the day shown to users when they log in.";
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = {
+
+    environment.systemPackages =
+      # Include the PAM modules in the system path mostly for the manpages.
+      [ pkgs.pam ]
+      ++ optional config.users.ldap.enable pam_ldap
+      ++ optional config.services.sssd.enable pkgs.sssd
+      ++ optionals config.krb5.enable [pam_krb5 pam_ccreds]
+      ++ optionals config.security.pam.enableOTPW [ pkgs.otpw ]
+      ++ optionals config.security.pam.oath.enable [ pkgs.oathToolkit ]
+      ++ optionals config.security.pam.p11.enable [ pam_p11 ]
+      ++ optionals config.security.pam.u2f.enable [ pkgs.pam_u2f ];
+
+    boot.supportedFilesystems = optionals config.security.pam.enableEcryptfs [ "ecryptfs" ];
+
+    security.wrappers = {
+      unix_chkpwd = {
+        source = "${pkgs.pam}/sbin/unix_chkpwd.orig";
+        owner = "root";
+        setuid = true;
+      };
+    };
+
+    environment.etc = mapAttrs' makePAMService config.security.pam.services;
+
+    security.pam.services =
+      { other.text =
+          ''
+            auth     required pam_warn.so
+            auth     required pam_deny.so
+            account  required pam_warn.so
+            account  required pam_deny.so
+            password required pam_warn.so
+            password required pam_deny.so
+            session  required pam_warn.so
+            session  required pam_deny.so
+          '';
+
+        # Most of these should be moved to specific modules.
+        i3lock = {};
+        i3lock-color = {};
+        vlock = {};
+        xlock = {};
+        xscreensaver = {};
+
+        runuser = { rootOK = true; unixAuth = false; setEnvironment = false; };
+
+        /* FIXME: should runuser -l start a systemd session? Currently
+           it complains "Cannot create session: Already running in a
+           session". */
+        runuser-l = { rootOK = true; unixAuth = false; };
+      };
+
+  };
+
+}
--- a/nixops/pam_p11/pam_p11.nix
+++ b/nixops/pam_p11/pam_p11.nix
@ -0,0 +1,23 @@
+{ stdenv, fetchFromGitHub, autoreconfHook, pkg-config, openssl, libp11, pam }:
+
+stdenv.mkDerivation rec {
+  pname = "pam_p11";
+  version = "0.3.1";
+
+  src = fetchFromGitHub {
+    owner = "OpenSC";
+    repo = "pam_p11";
+    rev = "pam_p11-${version}";
+    sha256 = "1caidy18rq5zk82d51x8vwidmkhwmanf3qm25x1yrdlbhxv6m7lk";
+  };
+
+  patchPhase =
+    ''
+    substituteInPlace src/match_openssh.c --replace \
+      '"%s/.ssh/authorized_keys", pw->pw_dir)' \
+      '"/etc/ssh/authorized_keys.d/%s", pw->pw_name)'
+    '';
+
+  nativeBuildInputs = [ autoreconfHook pkg-config ];
+  buildInputs = [ pam openssl libp11 ];
+}
--- a/nixops/rpi.nix
+++ b/nixops/rpi.nix
@ -0,0 +1,63 @@
+{ host, rpi4 }:
+
+{ config, pkgs, ... }:
+let
+  m-labs = import (fetchTarball https://nixbld.m-labs.hk/channel/custom/artiq/full/artiq-full/nixexprs.tar.xz) { inherit pkgs; };
+in
+{
+  deployment.targetHost = host;
+  nixpkgs.system = "aarch64-linux";
+
+  boot.loader.grub.enable = false;
+
+  boot.loader.generic-extlinux-compatible.enable = !rpi4;
+  boot.loader.raspberryPi = pkgs.lib.mkIf rpi4 {
+    enable = true;
+    version = 4;
+  };
+  boot.kernelPackages = pkgs.lib.mkIf rpi4 pkgs.linuxPackages_latest;
+
+  fileSystems = if rpi4 then {
+    "/boot" = {
+      device = "/dev/disk/by-label/FIRMWARE";
+      fsType = "vfat";
+    };
+    "/" = {
+      device = "/dev/disk/by-label/NIXOS_SD";
+      fsType = "ext4";
+    };
+  } else {
+    "/" = {
+      device = "/dev/disk/by-label/NIXOS_SD";
+      fsType = "ext4";
+    };
+  };
+
+  services.openssh.enable = true;
+  services.openssh.passwordAuthentication = false;
+
+  networking.hostName = host;
+  time.timeZone = "Asia/Hong_Kong";
+
+  users.extraGroups.plugdev = { };
+  users.mutableUsers = false;
+  users.defaultUserShell = pkgs.fish;
+  users.extraUsers = (import ./common-users.nix { inherit pkgs; }) // {
+    nix = {
+      isNormalUser = true;
+    };
+  };
+  security.sudo.wheelNeedsPassword = false;
+  services.udev.packages = [ m-labs.openocd ];
+
+  documentation.enable = false;
+  environment.systemPackages = with pkgs; [
+    psmisc wget vim git usbutils lm_sensors file telnet mosh tmux xc3sprog m-labs.openocd screen gdb minicom picocom
+  ];
+  programs.fish.enable = true;
+  programs.wireshark.enable = true;
+
+  nix.binaryCachePublicKeys = ["nixbld.m-labs.hk-1:5aSRVA5b320xbNvu30tqxVPXpld73bhtOeH6uAjRyHc="];
+  nix.binaryCaches = ["https://cache.nixos.org" "https://nixbld.m-labs.hk"];
+  nix.trustedUsers = ["root" "nix"];
+}
--- a/nixops/zeus-hardware-configuration.nix
+++ b/nixops/zeus-hardware-configuration.nix
@ -0,0 +1,33 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [ <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
+    ];
+
+  boot.initrd.availableKernelModules = [ "xhci_pci" "ahci" "nvme" "usbhid" "usb_storage" "sd_mod" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" =
+    { device = "/dev/disk/by-uuid/890b20a2-08d5-4635-b3a7-003ad4a11a19";
+      fsType = "ext4";
+    };
+
+  fileSystems."/boot" =
+    { device = "/dev/disk/by-uuid/91B4-E546";
+      fsType = "vfat";
+    };
+
+  swapDevices = [ ];
+
+  nix.maxJobs = lib.mkDefault 16;
+  powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+}