Merge remote-tracking branch 'cd/master'

40 files changed, 334 insertions, 347 deletions

diff --git a/krebs/3modules/Reaktor.nix b/krebs/3modules/Reaktor.nix
index 92400139c..d58661a28 100644
--- a/krebs/3modules/Reaktor.nix
+++ b/krebs/3modules/Reaktor.nix
@@ -1,6 +1,6 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 let
 
   ReaktorConfig = pkgs.writeText "config.py" ''
@@ -16,7 +16,7 @@ let
 
   out = {
     options.krebs.Reaktor = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/apt-cacher-ng.nix b/krebs/3modules/apt-cacher-ng.nix
index 371d39b6f..46b405842 100644
--- a/krebs/3modules/apt-cacher-ng.nix
+++ b/krebs/3modules/apt-cacher-ng.nix
@@ -1,6 +1,6 @@
 { config, pkgs, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   acng-config = pkgs.writeTextFile {
     name = "acng-configuration";
@@ -151,5 +151,5 @@ let
 in
 {
   options.krebs.apt-cacher-ng = api;
-  config = mkIf cfg.enable imp;
+  config = lib.mkIf cfg.enable imp;
 }
diff --git a/krebs/3modules/backup.nix b/krebs/3modules/backup.nix
index 66a325ed9..0aa86dec9 100644
--- a/krebs/3modules/backup.nix
+++ b/krebs/3modules/backup.nix
@@ -1,9 +1,9 @@
 { config, lib, pkgs, ... }:
-with lib;
+with config.krebs.lib;
 let
   out = {
     options.krebs.backup = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   cfg = config.krebs.backup;
@@ -210,7 +210,7 @@ let
       | ${pkgs.coreutils}/bin/head -1; }
   '';
 
-  # Note that we don't escape word on purpose, so we deref shell vars.
+  # Note that we don't escape word on purpose, so we can deref shell vars.
   # TODO type word
   network-ssh-port = host: word: ''
     case ${word} in
diff --git a/krebs/3modules/bepasty-server.nix b/krebs/3modules/bepasty-server.nix
index e74841205..9e777a5ef 100644
--- a/krebs/3modules/bepasty-server.nix
+++ b/krebs/3modules/bepasty-server.nix
@@ -1,6 +1,6 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   gunicorn = pkgs.pythonPackages.gunicorn;
   bepasty = pkgs.pythonPackages.bepasty-server;
@@ -10,8 +10,8 @@ let
 
   out = {
     options.krebs.bepasty = api;
-    config = mkIf cfg.enable (mkMerge [
-      (mkIf cfg.serveNginx nginx-imp)
+    config = lib.mkIf cfg.enable (lib.mkMerge [
+      (lib.mkIf cfg.serveNginx nginx-imp)
       imp
     ]);
   };
diff --git a/krebs/3modules/build.nix b/krebs/3modules/build.nix
index 3530fd595..a1f446188 100644
--- a/krebs/3modules/build.nix
+++ b/krebs/3modules/build.nix
@@ -1,6 +1,6 @@
 { config, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 
 let
   out = {
@@ -51,6 +51,7 @@ let
         source = config.krebs.build.source;
         target-user = maybeEnv "target_user" "root";
         target-host = maybeEnv "target_host" config.krebs.build.host.name;
+        target-port = maybeEnv "target_port" "22";
         target-path = maybeEnv "target_path" "/var/src";
         out = ''
           #! /bin/sh
@@ -62,7 +63,8 @@ let
           }
 
           echo ${shell.escape git-script} \
-            | ssh ${shell.escape "${target-user}@${target-host}"} -T
+            | ssh -p ${shell.escape target-port} \
+                  ${shell.escape "${target-user}@${target-host}"} -T
 
           unset tmpdir
           trap '
@@ -93,6 +95,7 @@ let
                     (attrNames file-specs)} \
                   --delete \
                   -vFrlptD \
+                  -e ${shell.escape "ssh -p ${target-port}"} \
                   ${shell.escape target-path}/ \
                   ${shell.escape "${target-user}@${target-host}:${target-path}"}
         '';
diff --git a/krebs/3modules/buildbot/master.nix b/krebs/3modules/buildbot/master.nix
index 74385a433..825cb3413 100644
--- a/krebs/3modules/buildbot/master.nix
+++ b/krebs/3modules/buildbot/master.nix
@@ -1,6 +1,6 @@
 { config, pkgs, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   buildbot = pkgs.buildbot;
   buildbot-master-config = pkgs.writeText "buildbot-master.cfg" ''
@@ -381,5 +381,5 @@ let
 in
 {
   options.krebs.buildbot.master = api;
-  config = mkIf cfg.enable imp;
+  config = lib.mkIf cfg.enable imp;
 }
diff --git a/krebs/3modules/buildbot/slave.nix b/krebs/3modules/buildbot/slave.nix
index 0e7796d8a..7705ac31c 100644
--- a/krebs/3modules/buildbot/slave.nix
+++ b/krebs/3modules/buildbot/slave.nix
@@ -1,6 +1,6 @@
 { config, pkgs, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   buildbot-slave-init = pkgs.writeText "buildbot-slave.tac" ''
     import os
@@ -182,5 +182,5 @@ let
 in
 {
   options.krebs.buildbot.slave = api;
-  config = mkIf cfg.enable imp;
+  config = lib.mkIf cfg.enable imp;
 }
diff --git a/krebs/3modules/current.nix b/krebs/3modules/current.nix
index 41941e289..9f63e33ac 100644
--- a/krebs/3modules/current.nix
+++ b/krebs/3modules/current.nix
@@ -1,13 +1,13 @@
 { config, pkgs, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 
 let
   cfg = config.krebs.current;
 
   out = {
     options.krebs.current = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/default.nix b/krebs/3modules/default.nix
index 060b4445d..c06f3754e 100644
--- a/krebs/3modules/default.nix
+++ b/krebs/3modules/default.nix
@@ -1,6 +1,6 @@
 { config, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs;
 
@@ -9,9 +9,9 @@ let
       ./apt-cacher-ng.nix
       ./backup.nix
       ./bepasty-server.nix
-      ./build.nix
       ./buildbot/master.nix
       ./buildbot/slave.nix
+      ./build.nix
       ./current.nix
       ./exim-retiolum.nix
       ./exim-smarthost.nix
@@ -20,19 +20,21 @@ let
       ./git.nix
       ./go.nix
       ./iptables.nix
+      ./lib.nix
       ./nginx.nix
       ./nixpkgs.nix
       ./per-user.nix
       ./Reaktor.nix
-      ./retiolum-bootstrap.nix
       ./realwallpaper.nix
+      ./retiolum-bootstrap.nix
       ./retiolum.nix
+      ./setuid.nix
       ./tinc_graphs.nix
       ./urlwatch.nix
       ./repo-sync.nix
     ];
     options.krebs = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
@@ -83,13 +85,13 @@ let
     };
   };
 
-  imp = mkMerge [
-    { krebs = import ./lass { inherit lib; }; }
-    { krebs = import ./makefu { inherit lib; }; }
-    { krebs = import ./miefda { inherit lib; }; }
-    { krebs = import ./mv { inherit lib; }; }
-    { krebs = import ./shared { inherit lib; }; }
-    { krebs = import ./tv { inherit lib; }; }
+  imp = lib.mkMerge [
+    { krebs = import ./lass   { inherit config lib; }; }
+    { krebs = import ./makefu { inherit config lib; }; }
+    { krebs = import ./miefda { inherit config lib; }; }
+    { krebs = import ./mv     { inherit config lib; }; }
+    { krebs = import ./shared { inherit config lib; }; }
+    { krebs = import ./tv     { inherit config lib; }; }
     {
       krebs.dns.providers = {
         de.krebsco = "zones";
diff --git a/krebs/3modules/exim-retiolum.nix b/krebs/3modules/exim-retiolum.nix
index ea012c38c..1722eef1f 100644
--- a/krebs/3modules/exim-retiolum.nix
+++ b/krebs/3modules/exim-retiolum.nix
@@ -1,12 +1,12 @@
 { config, pkgs, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.exim-retiolum;
 
   out = {
     options.krebs.exim-retiolum = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/exim-smarthost.nix b/krebs/3modules/exim-smarthost.nix
index a564430ea..267ee2900 100644
--- a/krebs/3modules/exim-smarthost.nix
+++ b/krebs/3modules/exim-smarthost.nix
@@ -1,13 +1,12 @@
 { config, pkgs, lib, ... }:
 
-with builtins;
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.exim-smarthost;
 
   out = {
     options.krebs.exim-smarthost = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/fetchWallpaper.nix b/krebs/3modules/fetchWallpaper.nix
index 225f00803..53fe0839d 100644
--- a/krebs/3modules/fetchWallpaper.nix
+++ b/krebs/3modules/fetchWallpaper.nix
@@ -1,13 +1,13 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 
 let
   cfg = config.krebs.fetchWallpaper;
 
   out = {
     options.krebs.fetchWallpaper = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/git.nix b/krebs/3modules/git.nix
index 11cf21b5f..a9542718d 100644
--- a/krebs/3modules/git.nix
+++ b/krebs/3modules/git.nix
@@ -1,4 +1,4 @@
-{ config, pkgs, lib, ... }:
+{ config, lib, pkgs, ... }:
 
 # TODO unify logging of shell scripts to user and journal
 # TODO move all scripts to ${etcDir}, so ControlMaster connections
@@ -6,13 +6,13 @@
 # TODO when authorized_keys changes, then restart ssh
 #       (or kill already connected users somehow)
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.git;
 
   out = {
     options.krebs.git = api;
-    config = mkIf cfg.enable (mkMerge [
+    config = with lib; mkIf cfg.enable (mkMerge [
       (mkIf cfg.cgit cgit-imp)
       git-imp
     ]);
@@ -86,7 +86,7 @@ let
         singleton {
           user = [ config.krebs.users.tv ];
           repo = [ testing ]; # see literal example of repos
-          perm = push "refs/*" (with lib.git; [
+          perm = push "refs/*" (with config.krebs.lib.git; [
             non-fast-forward create delete merge
           ]);
         }
diff --git a/krebs/3modules/github-hosts-sync.nix b/krebs/3modules/github-hosts-sync.nix
index 2aa18d53a..1d3873232 100644
--- a/krebs/3modules/github-hosts-sync.nix
+++ b/krebs/3modules/github-hosts-sync.nix
@@ -1,12 +1,12 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.github-hosts-sync;
 
   out = {
     options.krebs.github-hosts-sync = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/go.nix b/krebs/3modules/go.nix
index 08a93dab7..52a104bb9 100644
--- a/krebs/3modules/go.nix
+++ b/krebs/3modules/go.nix
@@ -1,13 +1,13 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 
 let
   cfg = config.krebs.go;
 
   out = {
     options.krebs.go = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/lass/default.nix b/krebs/3modules/lass/default.nix
index 749d3ff49..41a609105 100644
--- a/krebs/3modules/lass/default.nix
+++ b/krebs/3modules/lass/default.nix
@@ -1,6 +1,6 @@
-{ lib, ... }:
+{ config, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 
 {
   hosts = {
diff --git a/krebs/3modules/lib.nix b/krebs/3modules/lib.nix
new file mode 100644
index 000000000..b19f275b5
--- /dev/null
+++ b/krebs/3modules/lib.nix
@@ -0,0 +1,15 @@
+{ config, pkgs, lib, ... }:
+with lib;
+let
+  out = {
+    options.krebs.lib = api;
+    config = imp;
+  };
+  api = mkOption {
+    default = {};
+    type = types.attrs;
+  };
+  imp = {
+    krebs.lib = lib // import ../4lib { inherit lib; } // builtins;
+  };
+in out
diff --git a/krebs/3modules/makefu/default.nix b/krebs/3modules/makefu/default.nix
index 2811c0c52..ca83d6906 100644
--- a/krebs/3modules/makefu/default.nix
+++ b/krebs/3modules/makefu/default.nix
@@ -1,6 +1,6 @@
-{ lib, ... }:
+{ config, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 
 {
   hosts = {
@@ -292,8 +292,8 @@ with lib;
       cores = 1;
       nets = {
         retiolm = {
-          addrs4 = ["10.243.214.15/32"];
-          addrs6 = ["42:5a02:2c30:c1b1:3f2e:7c19:2496:a732/128"];
+          addrs4 = ["10.243.214.15"];
+          addrs6 = ["42:5a02:2c30:c1b1:3f2e:7c19:2496:a732"];
           aliases = [
               "wbob.retiolum"
           ];
diff --git a/krebs/3modules/miefda/default.nix b/krebs/3modules/miefda/default.nix
index 0cfa8bd27..6587ad92d 100644
--- a/krebs/3modules/miefda/default.nix
+++ b/krebs/3modules/miefda/default.nix
@@ -1,6 +1,6 @@
-{ lib, ... }:
+{ config, lib, ... }:
 
-with lib;
+with config.krebs.lib;
 
 {
   hosts = {
diff --git a/krebs/3modules/mv/default.nix b/krebs/3modules/mv/default.nix
index 8803cb249..33f941aae 100644
--- a/krebs/3modules/mv/default.nix
+++ b/krebs/3modules/mv/default.nix
@@ -1,6 +1,6 @@
-{ lib, ... }:
+{ config, ... }:
 
-with lib;
+with config.krebs.lib;
 
 {
   hosts = {
diff --git a/krebs/3modules/nginx.nix b/krebs/3modules/nginx.nix
index 921771033..7b7163071 100644
--- a/krebs/3modules/nginx.nix
+++ b/krebs/3modules/nginx.nix
@@ -1,13 +1,12 @@
-{ config, pkgs, lib, ... }:
+{ config, lib, pkgs, ... }:
 
-with builtins;
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.nginx;
 
   out = {
     options.krebs.nginx = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
@@ -34,6 +33,7 @@ let
         };
         locations = mkOption {
           type = with types; listOf (attrsOf str);
+          default = [];
         };
         extraConfig = mkOption {
           type = with types; string;
@@ -76,8 +76,8 @@ let
     server {
       ${concatMapStringsSep "\n" (x: "listen ${x};") listen}
       server_name ${toString server-names};
-      ${extraConfig}
-      ${indent (concatStrings (map to-location locations))}
+      ${indent extraConfig}
+      ${indent (concatMapStrings to-location locations)}
     }
   '';
 
diff --git a/krebs/3modules/nixpkgs.nix b/krebs/3modules/nixpkgs.nix
index 4129f9483..5816b8a30 100644
--- a/krebs/3modules/nixpkgs.nix
+++ b/krebs/3modules/nixpkgs.nix
@@ -1,11 +1,11 @@
-{ config, pkgs, lib, ... }:
-with lib;
+{ config, lib, pkgs, ... }:
+with config.krebs.lib;
 let
   cfg = config.krebs.nixpkgs;
 
   out = {
     options.krebs.nixpkgs = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
@@ -37,7 +37,7 @@ let
     };
   };
 
-  imp = mkIf (cfg.allowUnfreePredicate != null) {
+  imp = lib.mkIf (cfg.allowUnfreePredicate != null) {
     nixpkgs.config.allowUnfreePredicate = cfg.allowUnfreePredicate;
   };
 in out
diff --git a/krebs/3modules/per-user.nix b/krebs/3modules/per-user.nix
index ee213deda..13da5c4c3 100644
--- a/krebs/3modules/per-user.nix
+++ b/krebs/3modules/per-user.nix
@@ -1,6 +1,6 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 
 let
   cfg = config.krebs.per-user;
diff --git a/krebs/3modules/realwallpaper.nix b/krebs/3modules/realwallpaper.nix
index b377368f7..df374e184 100644
--- a/krebs/3modules/realwallpaper.nix
+++ b/krebs/3modules/realwallpaper.nix
@@ -1,12 +1,12 @@
-arg@{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.realwallpaper;
 
   out = {
     options.krebs.realwallpaper = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/retiolum-bootstrap.nix b/krebs/3modules/retiolum-bootstrap.nix
index 65bb51193..40382d098 100644
--- a/krebs/3modules/retiolum-bootstrap.nix
+++ b/krebs/3modules/retiolum-bootstrap.nix
@@ -1,12 +1,12 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.retiolum-bootstrap;
 
   out = {
     options.krebs.retiolum-bootstrap = api;
-    config = mkIf cfg.enable imp ;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/retiolum.nix b/krebs/3modules/retiolum.nix
index 407695273..d0162eae9 100644
--- a/krebs/3modules/retiolum.nix
+++ b/krebs/3modules/retiolum.nix
@@ -1,11 +1,11 @@
 { config, pkgs, lib, ... }:
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.retiolum;
 
   out = {
     options.krebs.retiolum = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/3modules/setuid.nix b/krebs/3modules/setuid.nix
new file mode 100644
index 000000000..1137788d8
--- /dev/null
+++ b/krebs/3modules/setuid.nix
@@ -0,0 +1,75 @@
+{ config, pkgs, lib, ... }:
+with config.krebs.lib;
+let
+  cfg = config.krebs.setuid;
+
+  out = {
+    options.krebs.setuid = api;
+    config = imp;
+  };
+
+  api = mkOption {
+    default = {};
+    type = let
+      # TODO make wrapperDir configurable
+      inherit (config.security) wrapperDir;
+      inherit (config.users) groups users;
+    in types.attrsOf (types.submodule ({ config, ... }: {
+      options = {
+        name = mkOption {
+          type = types.filename;
+          default = config._module.args.name;
+        };
+        filename = mkOption {
+          type = mkOptionType {
+            # TODO unyuck string and merge with toC
+            name = "derivation or string";
+            check = x:
+              isDerivation x ||
+              isString x;
+          };
+          apply = toString;
+        };
+        owner = mkOption {
+          default = "root";
+          type = types.enum (attrNames users);
+        };
+        group = mkOption {
+          default = "root";
+          type = types.enum (attrNames groups);
+        };
+        mode = mkOption {
+          default = "4710";
+          type = mkOptionType {
+            # TODO admit symbolic mode
+            name = "octal mode";
+            check = x:
+              isString x &&
+              match "[0-7][0-7][0-7][0-7]" x != null;
+          };
+        };
+        activate = mkOption {
+          type = types.str;
+          visible = false;
+          readOnly = true;
+        };
+      };
+      config.activate = let
+        src = pkgs.execve config.name {
+          inherit (config) filename;
+        };
+        dst = "${wrapperDir}/${config.name}";
+      in ''
+        cp ${src} ${dst}
+        chown ${config.owner}.${config.group} ${dst}
+        chmod ${config.mode} ${dst}
+      '';
+    }));
+  };
+
+  imp = {
+    system.activationScripts."krebs.setuid" = stringAfter [ "setuid" ]
+      (concatMapStringsSep "\n" (getAttr "activate") (attrValues cfg));
+  };
+
+in out
diff --git a/krebs/3modules/shared/default.nix b/krebs/3modules/shared/default.nix
index df4c529bf..208b596f8 100644
--- a/krebs/3modules/shared/default.nix
+++ b/krebs/3modules/shared/default.nix
@@ -1,9 +1,8 @@
-{ lib, ... }:
-
-with lib;
+{ config, ... }:
 
+with config.krebs.lib;
 let
-  testHosts = lib.genAttrs [
+  testHosts = genAttrs [
     "test-arch"
     "test-centos6"
     "test-centos7"
diff --git a/krebs/3modules/tinc_graphs.nix b/krebs/3modules/tinc_graphs.nix
index dc0484a8b..2692de982 100644
--- a/krebs/3modules/tinc_graphs.nix
+++ b/krebs/3modules/tinc_graphs.nix
@@ -1,6 +1,6 @@
 { config, lib, pkgs, ... }:
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.tinc_graphs;
   internal_dir = "${cfg.workingDir}/internal";
@@ -8,7 +8,7 @@ let
 
   out = {
     options.krebs.tinc_graphs = api;
-    config = mkIf cfg.enable imp ;
+    config = lib.mkIf cfg.enable imp ;
   };
 
   api = {
diff --git a/krebs/3modules/tv/default.nix b/krebs/3modules/tv/default.nix
index 9a0b99396..f8d3d8671 100644
--- a/krebs/3modules/tv/default.nix
+++ b/krebs/3modules/tv/default.nix
@@ -1,6 +1,6 @@
-{ lib, ... }:
+{ config, ... }:
 
-with lib;
+with config.krebs.lib;
 
 {
   dns.providers = {
diff --git a/krebs/3modules/urlwatch.nix b/krebs/3modules/urlwatch.nix
index 7a9fb55fd..cd4976a21 100644
--- a/krebs/3modules/urlwatch.nix
+++ b/krebs/3modules/urlwatch.nix
@@ -5,14 +5,14 @@
 # cache = url: "${cfg.dataDir}/.urlwatch/cache/${hashString "sha1" url}"
 # TODO hooks.py
 
-with lib;
+with config.krebs.lib;
 let
   cfg = config.krebs.urlwatch;
 
   # TODO assert sendmail's existence
   out = {
     options.krebs.urlwatch = api;
-    config = mkIf cfg.enable imp;
+    config = lib.mkIf cfg.enable imp;
   };
 
   api = {
diff --git a/krebs/4lib/default.nix b/krebs/4lib/default.nix
index 4d7e0b549..d5b6d03ac 100644
--- a/krebs/4lib/default.nix
+++ b/krebs/4lib/default.nix
@@ -26,11 +26,15 @@ let out = rec {
   shell = import ./shell.nix { inherit lib; };
   tree = import ./tree.nix { inherit lib; };
 
-  toC = x: {
+  toC = x: let
+    type = typeOf x;
+    reject = throw "cannot convert ${type}";
+  in {
     list = "{ ${concatStringsSep ", " (map toC x)} }";
     null = "NULL";
+    set = if isDerivation x then toJSON x else reject;
     string = toJSON x; # close enough
-  }.${typeOf x};
+  }.${type} or reject;
 
   subdirsOf = path:
     mapAttrs (name: _: path + "/${name}")
diff --git a/krebs/4lib/infest/install-nix.sh b/krebs/4lib/infest/install-nix.sh
deleted file mode 100644
index af1a8bd16..000000000
--- a/krebs/4lib/infest/install-nix.sh
+++ /dev/null
@@ -1,50 +0,0 @@
-#! /bin/sh
-set -efu
-
-nix_url=https://nixos.org/releases/nix/nix-1.10/nix-1.10-x86_64-linux.tar.bz2
-nix_sha256=504f7a3a85fceffb8766ae5e1005de9e02e489742f5a63cc3e7552120b138bf4
-
-install_nix() {(
-
-  # install nix on host (cf. https://nixos.org/nix/install)
-  if ! test -e /root/.nix-profile/etc/profile.d/nix.sh; then
-    (
-      verify() {
-        printf '%s  %s\n' $nix_sha256  $(basename $nix_url) | sha256sum -c
-      }
-      if ! verify; then
-        curl -C - -O "$nix_url"
-        verify
-      fi
-    )
-    nix_src_dir=$(basename $nix_url .tar.bz2)
-    tar jxf $nix_src_dir.tar.bz2
-    $nix_src_dir/install
-  fi
-
-  . /root/.nix-profile/etc/profile.d/nix.sh
-
-  for i in \
-    bash \
-    coreutils \
-    # This line intentionally left blank.
-  do
-    if ! nix-env -q $i | grep -q .; then
-      nix-env -iA nixpkgs.pkgs.$i
-    fi
-  done
-
-  # install nixos-install
-  if ! type nixos-install 2>/dev/null; then
-    nixpkgs_expr='import <nixpkgs> { system = builtins.currentSystem; }'
-    nixpkgs_path=$(find /nix/store -mindepth 1 -maxdepth 1 -name *-nixpkgs-* -type d)
-    nix-env \
-      --arg config "{ nix.package = ($nixpkgs_expr).nix; }" \
-      --arg pkgs "$nixpkgs_expr" \
-      --arg modulesPath 'throw "no modulesPath"' \
-      -f $nixpkgs_path/nixpkgs/nixos/modules/installer/tools/tools.nix \
-      -iA config.system.build.nixos-install
-  fi
-)}
-
-install_nix "$@"
diff --git a/krebs/4lib/infest/prepare.sh b/krebs/4lib/infest/prepare.sh
index 0bfc49380..b3824c7d4 100644
--- a/krebs/4lib/infest/prepare.sh
+++ b/krebs/4lib/infest/prepare.sh
@@ -1,6 +1,9 @@
 #! /bin/sh
 set -efu
 
+nix_url=https://nixos.org/releases/nix/nix-1.10/nix-1.10-x86_64-linux.tar.bz2
+nix_sha256=504f7a3a85fceffb8766ae5e1005de9e02e489742f5a63cc3e7552120b138bf4
+
 prepare() {(
   if test -e /etc/os-release; then
     . /etc/os-release
@@ -33,6 +36,13 @@ prepare() {(
             ;;
         esac
         ;;
+      nixos)
+        case $(cat /proc/cmdline) in
+          *' root=LABEL=NIXOS_ISO '*)
+            prepare_nixos_iso "$@"
+            exit
+        esac
+        ;;
     esac
   elif test -e /etc/centos-release; then
     case $(cat /etc/centos-release) in
@@ -70,7 +80,25 @@ prepare_debian() {
   prepare_common
 }
 
-prepare_common() {
+prepare_nixos_iso() {
+  mountpoint /mnt
+
+  type git 2>/dev/null || nix-env -iA nixos.git
+
+  mkdir -p /mnt/"$target_path"
+  mkdir -p "$target_path"
+
+  if ! mountpoint "$target_path"; then
+    mount --rbind /mnt/"$target_path" "$target_path"
+  fi
+
+  mkdir -p bin
+  rm -f bin/nixos-install
+  cp "$(type -p nixos-install)" bin/nixos-install
+  sed -i "s@^NIX_PATH=\"[^\"]*\"@NIX_PATH=$target_path@" bin/nixos-install
+}
+
+prepare_common() {(
 
   if ! getent group nixbld >/dev/null; then
     groupadd -g 30000 -r nixbld
@@ -133,6 +161,50 @@ prepare_common() {
     mkdir -p /mnt/nix
     mount --bind /nix /mnt/nix
   fi
-}
+
+  #
+  # install nix
+  #
+
+  # install nix on host (cf. https://nixos.org/nix/install)
+  if ! test -e /root/.nix-profile/etc/profile.d/nix.sh; then
+    (
+      verify() {
+        printf '%s  %s\n' $nix_sha256  $(basename $nix_url) | sha256sum -c
+      }
+      if ! verify; then
+        curl -C - -O "$nix_url"
+        verify
+      fi
+    )
+    nix_src_dir=$(basename $nix_url .tar.bz2)
+    tar jxf $nix_src_dir.tar.bz2
+    $nix_src_dir/install
+  fi
+
+  . /root/.nix-profile/etc/profile.d/nix.sh
+
+  for i in \
+    bash \
+    coreutils \
+    # This line intentionally left blank.
+  do
+    if ! nix-env -q $i | grep -q .; then
+      nix-env -iA nixpkgs.pkgs.$i
+    fi
+  done
+
+  # install nixos-install
+  if ! type nixos-install 2>/dev/null; then
+    nixpkgs_expr='import <nixpkgs> { system = builtins.currentSystem; }'
+    nixpkgs_path=$(find /nix/store -mindepth 1 -maxdepth 1 -name *-nixpkgs-* -type d)
+    nix-env \
+      --arg config "{ nix.package = ($nixpkgs_expr).nix; }" \
+      --arg pkgs "$nixpkgs_expr" \
+      --arg modulesPath 'throw "no modulesPath"' \
+      -f $nixpkgs_path/nixpkgs/nixos/modules/installer/tools/tools.nix \
+      -iA config.system.build.nixos-install
+  fi
+)}
 
 prepare "$@"
diff --git a/krebs/4lib/types.nix b/krebs/4lib/types.nix
index 873f3ddfb..d0a537467 100644
--- a/krebs/4lib/types.nix
+++ b/krebs/4lib/types.nix
@@ -17,6 +17,7 @@ types // rec {
       };
       nets = mkOption {
         type = attrsOf net;
+        default = {};
       };
 
       extraZones = mkOption {
diff --git a/krebs/5pkgs/builders.nix b/krebs/5pkgs/builders.nix
index b3cb1c943..fa51857ba 100644
--- a/krebs/5pkgs/builders.nix
+++ b/krebs/5pkgs/builders.nix
@@ -1,19 +1,30 @@
-{ lib, pkgs, ... }:
-with lib;
-{
-  execve = name: { filename, argv, envp ? {}, destination ? "" }:
-    writeC name { inherit destination; } ''
-      #include <unistd.h>
-      int main () {
-        const char *filename = ${toC filename};
-        char *const argv[] = ${toC (argv ++ [null])};
-        char *const envp[] = ${toC (
-          mapAttrsToList (k: v: "${k}=${v}") envp ++ [null]
-        )};
-        execve(filename, argv, envp);
-        return -1;
-      }
-    '';
+{ config, lib, pkgs, ... }:
+with config.krebs.lib;
+rec {
+  execve = name: { filename, argv ? null, envp ? {}, destination ? "" }: let
+  in writeC name { inherit destination; } ''
+    #include <unistd.h>
+
+    static char *const filename = ${toC filename};
+
+    ${if argv == null
+      then /* Propagate arguments */ ''
+        #define MAIN_ARGS int argc, char **argv
+      ''
+      else /* Provide fixed arguments */ ''
+        #define MAIN_ARGS void
+        static char *const argv[] = ${toC (argv ++ [null])};
+      ''}
+
+    static char *const envp[] = ${toC (
+      mapAttrsToList (k: v: "${k}=${v}") envp ++ [null]
+    )};
+
+    int main (MAIN_ARGS) {
+      execve(filename, argv, envp);
+      return -1;
+    }
+  '';
 
   execveBin = name: cfg: execve name (cfg // { destination = "/bin/${name}"; });
 
diff --git a/krebs/5pkgs/default.nix b/krebs/5pkgs/default.nix
index 1cf3de56e..d395fe00a 100644
--- a/krebs/5pkgs/default.nix
+++ b/krebs/5pkgs/default.nix
@@ -1,5 +1,5 @@
-{ lib, pkgs, ... }@args:
-with lib;
+{ config, lib, pkgs, ... }@args:
+with config.krebs.lib;
 {
   nixpkgs.config.packageOverrides = pkgs: {
     haskellPackages = pkgs.haskellPackages.override {
diff --git a/krebs/5pkgs/noVNC/default.nix b/krebs/5pkgs/noVNC/default.nix
new file mode 100644
index 000000000..629d288ae
--- /dev/null
+++ b/krebs/5pkgs/noVNC/default.nix
@@ -0,0 +1,21 @@
+{ fetchgit, lib, stdenv, ... }:
+with builtins;
+with lib;
+stdenv.mkDerivation rec {
+  name = "${baseNameOf src.name}-${removePrefix "refs/tags/v" src.rev}";
+
+  src = fetchgit {
+    url = https://github.com/kanaka/noVNC;
+    rev = "refs/tags/v0.5.1";
+    sha256 = "1azsnppwnrsv3axj0r5bw8lfarkibgz5vhgcyj8dzn4afn98f55w";
+  };
+
+  phases = [
+    "unpackPhase"
+    "installPhase"
+  ];
+
+  installPhase = ''
+    cp -R . $out
+  '';
+}
diff --git a/krebs/5pkgs/vncdotool/default.nix b/krebs/5pkgs/vncdotool/default.nix
new file mode 100644
index 000000000..95e2ca706
--- /dev/null
+++ b/krebs/5pkgs/vncdotool/default.nix
@@ -0,0 +1,20 @@
+{ lib, pythonPackages, fetchurl, ... }:
+with pythonPackages; buildPythonPackage rec {
+  name = lib.removeSuffix ".tar.gz" (builtins.baseNameOf src.name);
+
+  src = fetchurl {
+    url = https://pypi.python.org/packages/source/v/vncdotool/vncdotool-0.9.0.tar.gz;
+    sha256 = "1hl44w4x9c8air0g6kp9h1af2vj4lmc50vnsxmca9g080740iyvi";
+  };
+
+  propagatedBuildInputs = [
+    twisted
+    pillow
+  ];
+
+  meta = {
+    homepage = https://github.com/sibson/vncdotool;
+    description = "A command line VNC client and python library";
+    license = lib.licenses.mit;
+  };
+}
diff --git a/krebs/default.nix b/krebs/default.nix
index 17c035896..93e006f3d 100644
--- a/krebs/default.nix
+++ b/krebs/default.nix
@@ -1,193 +1,8 @@
-assert false;
-
-{ current-host-name
-, current-user-name
-, lib
-, stockholm
-, StrictHostKeyChecking ? "yes"
-}:
-
-let out = {
-    inherit infest;
-    inherit init;
-    inherit nixos-install;
-  };
-
-  infest =
-    { system ? current-host-name
-    , target ? system
-    }@args: let
-      config = get-config system;
-    in ''
-      #! /bin/sh
-      # krebs.infest
-      set -efu
-
-      ${rootssh target ''
-        ${builtins.readFile ./4lib/infest/prepare.sh}
-        ${builtins.readFile ./4lib/infest/install-nix.sh}
-      ''}
-
-      (${nixos-install args})
-
-      ${rootssh target ''
-        ${builtins.readFile ./4lib/infest/finalize.sh}
-      ''}
-    '';
-
-  init =
-    { system ? current-host-name
-    }@args: let
-      config = get-config system;
-    in ''
-      #! /bin/sh
-      # krebs.init
-      set -efu
-
-      system=${lib.shell.escape system}
-      secrets_dir=${config.krebs.build.source.dir.secrets.path}
-      key_type=ed25519
-      key_file=$secrets_dir/ssh.id_$key_type
-      key_comment=$system
-
-      if test -e "$key_file"; then
-        echo "Warning: privkey already exists: $key_file" >&2
-      else
-        ssh-keygen \
-            -C "$key_comment" \
-            -t "$key_type" \
-            -f "$key_file" \
-            -N ""
-        rm "$key_file.pub"
-      fi
-
-      pubkey=$(ssh-keygen -y -f "$key_file")
-
-      cat<<EOF
-      # put following into config.krebs.hosts.$system:
-      ssh.privkey.path = <secrets/ssh.$key_type>;
-      ssh.pubkey = $(echo $pubkey | jq -R .);
-      EOF
-    '';
-
-  nixos-install =
-    { system ? current-host-name
-    , target ? system
-    }@args: let
-    in ''
-      #! /bin/sh
-      # krebs.nixos-install
-      (${populate (args // { root = "/mnt"; })})
-
-      ${rootssh target ''
-        export PATH; PATH=/root/.nix-profile/bin:$PATH
-
-        src=$(type -p nixos-install)
-        cat_src() {
-          sed < "$src" "$(
-            { sed < "$src" -n '
-                  /^if ! test -e "\$mountPoint\/\$NIXOS_CONFIG/,/^fi$/=
-                  /^nixpkgs=/=
-                  /^NIX_PATH=/,/^$/{/./=}
-
-                  # Disable: Copy the NixOS/Nixpkgs sources to the target as
-                  # the initial contents of the NixOS channel.
-                  /^srcs=/,/^ln -sfn /=
-                '
-            } | sed 's:$:s/^/#krebs#/:'
-          )"
-        }
-
-        # Location to insert `nix-install`
-        i=$(sed -n '/^echo "building the system configuration/=' "$src")
-
-        {
-          cat_src | sed -n "1,$i{p}"
-          cat ${doc (nix-install args)}
-          cat_src | sed -n "$i,\''${$i!p}"
-        } > nixos-install
-        chmod +x nixos-install
-
-        # Wrap inserted nix-install into chroot.
-        nix_env=$(cat_src | sed -n '
-          s:.*\(/nix/store/[a-z0-9]*-nix-[0-9.]\+/bin/nix-env\).*:\1:p;T;q
-        ')
-        echo "nix-env is $nix_env" >&2
-        findpkg() {(
-          name=$1
-          path=$(find /nix/store \
-              -mindepth 1 -maxdepth 1 -type d -name '*-'"$name"'-*' \
-            | head -n 1 | sed s:^/mnt::)
-          if echo "$path" | grep .; then
-            echo "$name is $path" >&2
-          else
-            echo "Error: package not found: $name" >&2
-            exit 1
-          fi
-        )}
-        cacert=$(findpkg cacert)
-        coreutils=$(findpkg coreutils)
-        cp "$cacert"/etc/ssl/certs/ca-bundle.crt /mnt/root/SSL_CERT_FILE
-        env="$coreutils/bin/env SSL_CERT_FILE=/root/SSL_CERT_FILE"
-        sed -i '
-          s:^NIX_PATH=:chroot $mountPoint '"$env"' &:
-          s:^nix-env:'"$nix_env"':
-        ' nixos-install
-
-        ./nixos-install
-      ''}
-    '';
-
-  doc = s:
-    let b = "EOF${builtins.hashString "sha256" s}"; in
-    ''
-    <<\${b}
-    ${s}
-    ${b}
-    '';
-
-  get-config = system: let
-    config = stockholm.users.${current-user-name}.${system}.config
-      or (abort "unknown system: ${system}, user: ${current-user-name}");
-  in config;
-
-  nix-install =
-    { system ? current-host-name
-    , target ? system
-    }:
-    let
-      config = get-config system;
-
-      nix-path =
-        lib.concatStringsSep ":"
-          (lib.mapAttrsToList (name: src: "${name}=${src.target-path}")
-            (config.krebs.build.source.dir //
-             config.krebs.build.source.git));
-    in ''
-      set -efu
-      NIX_PATH=${lib.shell.escape nix-path} \
-      nix-env \
-        --show-trace \
-        -f '<stockholm>' \
-        --argstr current-host-name ${lib.shell.escape current-host-name} \
-        --argstr current-user-name ${lib.shell.escape current-user-name} \
-        --profile ${lib.shell.escape config.krebs.build.profile} \
-        --set \
-        -A ${lib.escapeShellArg (lib.concatStringsSep "." [
-              "users"
-              config.krebs.build.user.name
-              config.krebs.build.host.name
-              "system"
-            ])}
-    '';
-
-  rootssh = target: script:
-    let
-      flags = "-o StrictHostKeyChecking=${StrictHostKeyChecking}";
-    in
-    "ssh ${flags} root@${target} -T ${doc ''
-      set -efu
-      ${script}
-    ''}";
-
-in out
+{ config, lib, pkgs, ... }:
+with config.krebs.lib;
+{
+  imports = [
+    ./3modules
+    ./5pkgs
+  ];
+}