Merge remote-tracking branch 'prism/master'

9 files changed, 936 insertions, 15 deletions

diff --git a/krebs/3modules/Reaktor.nix b/krebs/3modules/Reaktor.nix
index 0fca52203..92400139c 100644
--- a/krebs/3modules/Reaktor.nix
+++ b/krebs/3modules/Reaktor.nix
@@ -9,6 +9,7 @@ let
       ${cfg.overrideConfig}
       '' else ""}
       ## Extra Config
+      ${concatStringsSep "\n" (map (plug: plug.config) cfg.plugins)}
       ${cfg.extraConfig}
     '';
   cfg = config.krebs.Reaktor;
@@ -35,7 +36,6 @@ let
       '';
     };
 
-
     overrideConfig = mkOption {
       default = null;
       type = types.nullOr types.str;
@@ -44,6 +44,9 @@ let
         Reaktor default cfg can be retrieved via `reaktor get-config`
       '';
     };
+    plugins = mkOption {
+      default = [pkgs.ReaktorPlugins.nixos-version];
+    };
     extraConfig = mkOption {
       default = "";
       type = types.string;
@@ -51,6 +54,14 @@ let
         configuration appended to the default or overridden configuration
       '';
     };
+
+    workdir = mkOption {
+      default = "/var/lib/Reaktor";
+      type = types.str;
+      description = ''
+        Reaktor working directory
+      '';
+    };
     extraEnviron = mkOption {
       default = {};
       type = types.attrsOf types.str;
@@ -59,12 +70,17 @@ let
           REAKTOR_HOST
           REAKTOR_PORT
           REAKTOR_STATEDIR
-          REAKTOR_CHANNELS
 
           debug and nickname can be set separately via the Reaktor api
       '';
     };
-
+    channels = mkOption {
+      default = [ "#krebs" ];
+      type = types.listOf types.str;
+      description = ''
+        Channels the Reaktor should connect to at startup.
+      '';
+    };
     debug = mkOption {
       default = false;
       description = ''
@@ -79,7 +95,7 @@ let
       name = "Reaktor";
       uid = genid name;
       description = "Reaktor user";
-      home = "/var/lib/Reaktor";
+      home = cfg.workdir;
       createHome = true;
     };
 
@@ -101,6 +117,9 @@ let
         GIT_SSL_CAINFO = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";
         REAKTOR_NICKNAME = cfg.nickname;
         REAKTOR_DEBUG = (if cfg.debug  then "True" else "False");
+        REAKTOR_CHANNELS = lib.concatStringsSep "," cfg.channels;
+        state_dir = cfg.workdir;
+
         } // cfg.extraEnviron;
       serviceConfig= {
         ExecStartPre = pkgs.writeScript "Reaktor-init" ''
diff --git a/krebs/3modules/backup.nix b/krebs/3modules/backup.nix
new file mode 100644
index 000000000..01bb16a2b
--- /dev/null
+++ b/krebs/3modules/backup.nix
@@ -0,0 +1,286 @@
+{ config, lib, pkgs, ... }:
+with lib;
+let
+  out = {
+    options.krebs.backup = api;
+    config = mkIf cfg.enable imp;
+  };
+
+  cfg = config.krebs.backup;
+
+  api = {
+    enable = mkEnableOption "krebs.backup" // { default = true; };
+    plans = mkOption {
+      default = {};
+      type = types.attrsOf (types.submodule ({
+        # TODO enable = mkEnableOption "TODO" // { default = true; };
+        options = {
+          method = mkOption {
+            type = types.enum ["pull" "push"];
+          };
+          name = mkOption {
+            type = types.str;
+          };
+          src = mkOption {
+            type = types.krebs.file-location;
+          };
+          dst = mkOption {
+            type = types.krebs.file-location;
+          };
+          startAt = mkOption {
+            type = types.str;
+          };
+          snapshots = mkOption {
+            type = types.attrsOf (types.submodule {
+              options = {
+                format = mkOption {
+                  type = types.str; # TODO date's +FORMAT
+                };
+                retain = mkOption {
+                  type = types.nullOr types.int;
+                  default = null; # null = retain all snapshots
+                };
+              };
+            });
+          };
+        };
+      }));
+    };
+  };
+
+  imp = {
+    users.groups.backup.gid = genid "backup";
+    users.users = {}
+      // {
+        root.openssh.authorizedKeys.keys =
+          map (plan: plan.dst.host.ssh.pubkey)
+              (filter isPullSrc (attrValues cfg.plans))
+          ++
+          map (plan: plan.src.host.ssh.pubkey)
+              (filter isPushDst (attrValues cfg.plans))
+          ;
+      }
+      ;
+    systemd.services =
+      flip mapAttrs' (filterAttrs (_:isPullDst) cfg.plans) (name: plan: {
+        name = "backup.${name}.pull";
+        value = makePullService plan;
+      })
+      //
+      flip mapAttrs' (filterAttrs (_:isPushSrc) cfg.plans) (name: plan: {
+        name = "backup.${name}.push";
+        value = makePushService plan;
+      })
+      ;
+  };
+
+  isPushSrc = plan:
+    plan.method == "push" &&
+    plan.src.host.name == config.krebs.build.host.name;
+
+  isPullSrc = plan:
+    plan.method == "pull" &&
+    plan.src.host.name == config.krebs.build.host.name;
+
+  isPushDst = plan:
+    plan.method == "push" &&
+    plan.dst.host.name == config.krebs.build.host.name;
+
+  isPullDst = plan:
+    plan.method == "pull" &&
+    plan.dst.host.name == config.krebs.build.host.name;
+
+  # TODO push destination needs this in the dst.user's PATH
+  service-path = [
+    pkgs.coreutils
+    pkgs.gnused
+    pkgs.openssh
+    pkgs.rsync
+    pkgs.utillinux
+  ];
+
+  # TODO if there is plan.user, then use its privkey
+  makePushService = plan: assert isPushSrc plan; {
+    path = service-path;
+    serviceConfig = {
+      ExecStart = push plan;
+      Type = "oneshot";
+    };
+    startAt = plan.startAt;
+  };
+
+  makePullService = plan: assert isPullDst plan; {
+    path = service-path;
+    serviceConfig = {
+      ExecStart = pull plan;
+      Type = "oneshot";
+    };
+    startAt = plan.startAt;
+  };
+
+  push = plan: let
+    # We use writeDashBin and return the absolute path so systemd will produce
+    # nice names in the log, i.e. without the Nix store hash.
+    out = "${main}/bin/${main.name}";
+
+    main = writeDashBin "backup.${plan.name}.push" ''
+      set -efu
+      dst=${shell.escape plan.dst.path}
+
+      mkdir -m 0700 -p "$dst"
+      exec flock -n "$dst" ${critical-section}
+    '';
+
+    critical-section = writeDash "backup.${plan.name}.push.critical-section" ''
+      # TODO check if there is a previous
+      set -efu
+      identity=${shell.escape plan.src.host.ssh.privkey.path}
+      src=${shell.escape plan.src.path}
+      dst_target=${shell.escape "root@${getFQDN plan.dst.host}"}
+      dst_path=${shell.escape plan.dst.path}
+      dst=$dst_target:$dst_path
+
+      # Export NOW so runtime of rsync doesn't influence snapshot naming.
+      export NOW
+      NOW=$(date +%s)
+
+      echo >&2 "update snapshot: current; $src -> $dst"
+      rsync >&2 \
+          -aAXF --delete \
+          -e "ssh -F /dev/null -i $identity" \
+          --rsync-path ${shell.escape
+            "mkdir -m 0700 -p ${shell.escape plan.dst.path} && rsync"} \
+          --link-dest="$dst_path/current" \
+          "$src/" \
+          "$dst/.partial"
+
+      exec ssh -F /dev/null \
+          -i "$identity" \
+          "$dst_target" \
+          -T \
+          env NOW="$NOW" /bin/sh < ${remote-snapshot}
+      EOF
+    '';
+
+    remote-snapshot = writeDash "backup.${plan.name}.push.remote-snapshot" ''
+      set -efu
+      dst=${shell.escape plan.dst.path}
+
+      if test -e "$dst/current"; then
+        mv "$dst/current" "$dst/.previous"
+      fi
+      mv "$dst/.partial" "$dst/current"
+      rm -fR "$dst/.previous"
+      echo >&2
+
+      (${(take-snapshots plan).text})
+    '';
+
+  in out;
+
+  # TODO admit plan.dst.user and its ssh identity
+  pull = plan: let
+    # We use writeDashBin and return the absolute path so systemd will produce
+    # nice names in the log, i.e. without the Nix store hash.
+    out = "${main}/bin/${main.name}";
+
+    main = writeDashBin "backup.${plan.name}.pull" ''
+      set -efu
+      dst=${shell.escape plan.dst.path}
+
+      mkdir -m 0700 -p "$dst"
+      exec flock -n "$dst" ${critical-section}
+    '';
+
+    critical-section = writeDash "backup.${plan.name}.pull.critical-section" ''
+      # TODO check if there is a previous
+      set -efu
+      identity=${shell.escape plan.dst.host.ssh.privkey.path}
+      src=${shell.escape "root@${getFQDN plan.src.host}:${plan.src.path}"}
+      dst=${shell.escape plan.dst.path}
+
+      # Export NOW so runtime of rsync doesn't influence snapshot naming.
+      export NOW
+      NOW=$(date +%s)
+
+      echo >&2 "update snapshot: current; $dst <- $src"
+      mkdir -m 0700 -p ${shell.escape plan.dst.path}
+      rsync >&2 \
+          -aAXF --delete \
+          -e "ssh -F /dev/null -i $identity" \
+          --link-dest="$dst/current" \
+          "$src/" \
+          "$dst/.partial"
+      mv "$dst/current" "$dst/.previous"
+      mv "$dst/.partial" "$dst/current"
+      rm -fR "$dst/.previous"
+      echo >&2
+
+      exec ${take-snapshots plan}
+    '';
+  in out;
+
+  take-snapshots = plan: writeDash "backup.${plan.name}.take-snapshots" ''
+    set -efu
+    NOW=''${NOW-$(date +%s)}
+    dst=${shell.escape plan.dst.path}
+
+    snapshot() {(
+      : $ns $format $retain
+      name=$(date --date="@$NOW" +"$format")
+      if ! test -e "$dst/$ns/$name"; then
+        echo >&2 "create snapshot: $ns/$name"
+        mkdir -m 0700 -p "$dst/$ns"
+        rsync >&2 \
+            -aAXF --delete \
+            --link-dest="$dst/current" \
+            "$dst/current/" \
+            "$dst/$ns/.partial.$name"
+        mv "$dst/$ns/.partial.$name" "$dst/$ns/$name"
+        echo >&2
+      fi
+      case $retain in
+        ([0-9]*)
+          delete_from=$(($retain + 1))
+          ls -r "$dst/$ns" \
+            | sed -n "$delete_from,\$p" \
+            | while read old_name; do
+                echo >&2 "delete snapshot: $ns/$old_name"
+                rm -fR "$dst/$ns/$old_name"
+              done
+          ;;
+        (ALL)
+          :
+          ;;
+      esac
+    )}
+
+    ${concatStringsSep "\n" (mapAttrsToList (ns: { format, retain ? null, ... }:
+      toString (map shell.escape [
+        "ns=${ns}"
+        "format=${format}"
+        "retain=${if retain == null then "ALL" else toString retain}"
+        "snapshot"
+      ]))
+      plan.snapshots)}
+  '';
+
+  # TODO getFQDN: admit hosts in other domains
+  getFQDN = host: "${host.name}.${config.krebs.search-domain}";
+
+  writeDash = name: text: pkgs.writeScript name ''
+    #! ${pkgs.dash}/bin/dash
+    ${text}
+  '';
+
+  writeDashBin = name: text: pkgs.writeTextFile {
+    executable = true;
+    destination = "/bin/${name}";
+    name = name;
+    text = ''
+      #! ${pkgs.dash}/bin/dash
+      ${text}
+    '';
+  };
+
+in out
diff --git a/krebs/3modules/buildbot/master.nix b/krebs/3modules/buildbot/master.nix
new file mode 100644
index 000000000..74385a433
--- /dev/null
+++ b/krebs/3modules/buildbot/master.nix
@@ -0,0 +1,385 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+let
+  buildbot = pkgs.buildbot;
+  buildbot-master-config = pkgs.writeText "buildbot-master.cfg" ''
+    # -*- python -*-
+    from buildbot.plugins import *
+    import re
+    import json
+    c = BuildmasterConfig = {}
+
+    c['slaves'] = []
+    slaves = json.loads('${builtins.toJSON cfg.slaves}')
+    slavenames = [ s for s in slaves ]
+    for k,v in slaves.items():
+      c['slaves'].append(buildslave.BuildSlave(k, v))
+
+    # TODO: configure protocols?
+    c['protocols'] = {'pb': {'port': 9989}}
+
+    ####### Build Inputs
+    c['change_source'] = cs = []
+
+    ${ concatStringsSep "\n"
+    (mapAttrsToList (n: v: ''
+        #### Change_Source: Begin of ${n}
+        ${v}
+        #### Change_Source: End of ${n}
+      '') cfg.change_source )}
+
+    ####### Build Scheduler
+    c['schedulers'] = sched = []
+
+    ${ concatStringsSep "\n"
+    (mapAttrsToList (n: v: ''
+        #### Schedulers: Begin of ${n}
+        ${v}
+        #### Schedulers: End of ${n}
+      '') cfg.scheduler )}
+
+    ###### Builder
+    c['builders'] = bu = []
+    
+    # Builder Pre: Begin
+    ${cfg.builder_pre}
+    # Builder Pre: End
+
+    ${ concatStringsSep "\n"
+    (mapAttrsToList (n: v: ''
+        #### Builder: Begin of ${n}
+        ${v}
+        #### Builder: End of ${n}
+      '') cfg.builder )}
+
+
+    ####### Status
+    c['status'] = st = []
+
+    # If you want to configure this url, override with extraConfig
+    c['buildbotURL'] = "http://${config.networking.hostName}:${toString cfg.web.port}/"
+
+    ${optionalString (cfg.web.enable) ''
+      from buildbot.status import html
+      from buildbot.status.web import authz, auth
+      authz_cfg=authz.Authz(
+          auth=auth.BasicAuth([ ("${cfg.web.username}","${cfg.web.password}") ]),
+          # TODO: configure harder
+          gracefulShutdown = False,
+          forceBuild = 'auth',
+          forceAllBuilds = 'auth',
+          pingBuilder = False,
+          stopBuild = 'auth',
+          stopAllBuilds = 'auth',
+          cancelPendingBuild = 'auth'
+      )
+      # TODO: configure krebs.nginx
+      st.append(html.WebStatus(http_port=${toString cfg.web.port}, authz=authz_cfg))
+      ''}
+
+    ${optionalString (cfg.irc.enable) ''
+      from buildbot.status import words
+      irc = words.IRC("${cfg.irc.server}", "${cfg.irc.nick}",
+                      channels=${builtins.toJSON cfg.irc.channels},
+                      notify_events={
+                        'success': 1,
+                        'failure': 1,
+                        'exception': 1,
+                        'successToFailure': 1,
+                        'failureToSuccess': 1,
+                      }${optionalString cfg.irc.allowForce ",allowForce=True"})
+      c['status'].append(irc)
+      ''}
+
+    ${ concatStringsSep "\n"
+    (mapAttrsToList (n: v: ''
+        #### Status: Begin of ${n}
+        ${v}
+        #### Status: End of ${n}
+      '') cfg.status )}
+
+    ####### PROJECT IDENTITY
+    c['title'] = "${cfg.title}"
+    c['titleURL'] = "http://krebsco.de"
+
+
+    ####### DB URL
+    # TODO: configure
+    c['db'] = {
+        'db_url' : "sqlite:///state.sqlite",
+    }
+    ${cfg.extraConfig}
+    '';
+
+  cfg = config.krebs.buildbot.master;
+
+  api = {
+    enable = mkEnableOption "Buildbot Master";
+    title = mkOption {
+      default = "Buildbot CI";
+      type = types.str;
+      description = ''
+        Title of the Buildbot Installation
+      '';
+    };
+    workDir = mkOption {
+      default = "/var/lib/buildbot/master";
+      type = types.str;
+      description = ''
+        Path to build bot master directory.
+        Will be created on startup.
+      '';
+    };
+
+    secrets = mkOption {
+      default = [];
+      type = types.listOf types.str;
+      example = [ "cac.json" ];
+      description = ''
+        List of all the secrets in <secrets> which should be copied into the
+        buildbot master directory.
+      '';
+    };
+
+    slaves = mkOption {
+      default = {};
+      type = types.attrsOf types.str;
+      description = ''
+        Attrset of slavenames with their passwords
+        slavename = slavepassword
+      '';
+    };
+
+    change_source = mkOption {
+      default = {};
+      type = types.attrsOf types.str;
+      example = {
+        stockholm = ''
+          cs.append(changes.GitPoller(
+                  'http://cgit.gum/stockholm',
+                  workdir='stockholm-poller', branch='master',
+                  project='stockholm',
+                  pollinterval=120))
+        '';
+      };
+      description = ''
+        Attrset of all the change_sources which should be configured.
+        It will be directly included into the master configuration.
+
+        At the end an change object should be appended to <literal>cs</literal>
+      '';
+    };
+
+    scheduler = mkOption {
+      default = {};
+      type = types.attrsOf types.str;
+      example = {
+        force-scheduler = ''
+          sched.append(schedulers.ForceScheduler(
+                                      name="force",
+                                      builderNames=["full-tests"]))
+        '';
+      };
+      description = ''
+        Attrset of all the schedulers which should be configured.
+        It will be directly included into the master configuration.
+
+        At the end an change object should be appended to <literal>sched</literal>
+      '';
+    };
+
+    builder_pre = mkOption {
+      default = "";
+      type = types.lines;
+      example = ''
+        grab_repo = steps.Git(repourl=stockholm_repo, mode='incremental')
+      '';
+      description = ''
+        some code before the builders are being assembled.
+        can be used to define functions used by multiple builders
+      '';
+    };
+
+    builder = mkOption {
+      default = {};
+      type = types.attrsOf types.str;
+      example = {
+        fast-test = ''
+        '';
+      };
+      description = ''
+        Attrset of all the builder which should be configured.
+        It will be directly included into the master configuration.
+
+        At the end an change object should be appended to <literal>bu</literal>
+      '';
+    };
+
+    status = mkOption {
+      default = {};
+      type = types.attrsOf types.str;
+      description = ''
+        Attrset of all the extra status which should be configured.
+        It will be directly included into the master configuration.
+
+        At the end an change object should be appended to <literal>st</literal>
+
+        Right now IRC and Web status can be configured by setting
+        <literal>buildbot.master.irc.enable</literal> and
+        <literal>buildbot.master.web.enable</literal>
+      '';
+    };
+
+    # Configurable Stati
+    web = mkOption {
+      default = {};
+      type = types.submodule ({ config2, ... }: {
+        options = {
+          enable = mkEnableOption "Buildbot Master Web Status";
+          username = mkOption {
+            default = "krebs";
+            type = types.str;
+            description = ''
+              username for web authentication
+            '';
+          };
+          hostname = mkOption {
+            default = config.networking.hostName;
+            type = types.str;
+            description = ''
+              web interface Hostname
+            '';
+          };
+          password = mkOption {
+            default = "bob";
+            type = types.str;
+            description = ''
+              password for web authentication
+            '';
+          };
+          port = mkOption {
+            default = 8010;
+            type = types.int;
+            description = ''
+              port for buildbot web status
+            '';
+          };
+        };
+      });
+    };
+
+    irc = mkOption {
+      default = {};
+      type = types.submodule ({ config, ... }: {
+        options = {
+          enable = mkEnableOption "Buildbot Master IRC Status";
+          channels = mkOption {
+            default = [ "nix-buildbot-meetup" ];
+            type = with types; listOf str;
+            description = ''
+              irc channels the bot should connect to
+            '';
+          };
+          allowForce = mkOption {
+            default = false;
+            type = types.bool;
+            description = ''
+              Determines if builds can be forced via IRC
+            '';
+          };
+          nick = mkOption {
+            default = "nix-buildbot";
+            type = types.str;
+            description = ''
+              nickname for IRC
+            '';
+          };
+          server = mkOption {
+            default = "irc.freenode.net";
+            type = types.str;
+            description = ''
+              Buildbot Status IRC Server to connect to
+            '';
+          };
+        };
+      });
+    };
+
+    extraConfig = mkOption {
+      default = "";
+      type = types.lines;
+      description = ''
+        extra config appended to the generated master.cfg
+      '';
+    };
+  };
+
+  imp = {
+
+    users.extraUsers.buildbotMaster = {
+      uid = genid "buildbotMaster";
+      description = "Buildbot Master";
+      home = cfg.workDir;
+      createHome = false;
+    };
+
+    users.extraGroups.buildbotMaster = {
+      gid = 672626386;
+    };
+
+    systemd.services.buildbotMaster = {
+      description = "Buildbot Master";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      # TODO: add extra dependencies to master like svn and cvs
+      path = [ pkgs.git ];
+      environment = {
+        SSL_CERT_FILE = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";
+      };
+      serviceConfig = let
+        workdir="${lib.shell.escape cfg.workDir}";
+        secretsdir="${lib.shell.escape (toString <secrets>)}";
+      in {
+        PermissionsStartOnly = true;
+        Type = "forking";
+        PIDFile = "${workdir}/twistd.pid";
+        # TODO: maybe also prepare buildbot.tac?
+        ExecStartPre = pkgs.writeScript "buildbot-master-init" ''
+          #!/bin/sh
+          set -efux
+          if [ ! -e ${workdir} ];then
+            mkdir -p ${workdir}
+            ${buildbot}/bin/buildbot create-master -r -l 10 -f ${workdir}
+          fi
+          # always override the master.cfg
+          cp ${buildbot-master-config} ${workdir}/master.cfg
+
+          # copy secrets
+          ${ concatMapStringsSep "\n"
+            (f: "cp ${secretsdir}/${f} ${workdir}/${f}" ) cfg.secrets }
+          # sanity
+          ${buildbot}/bin/buildbot checkconfig ${workdir}
+
+          # TODO: maybe upgrade? not sure about this
+          #       normally we should write buildbot.tac by our own
+          # ${buildbot}/bin/buildbot upgrade-master ${workdir}
+
+          chmod 700 -R ${workdir}
+          chown buildbotMaster:buildbotMaster -R ${workdir}
+        '';
+        ExecStart = "${buildbot}/bin/buildbot start ${workdir}";
+        ExecStop = "${buildbot}/bin/buildbot stop ${workdir}";
+        ExecReload = "${buildbot}/bin/buildbot reconfig ${workdir}";
+        PrivateTmp = "true";
+        User = "buildbotMaster";
+        Restart = "always";
+        RestartSec = "10";
+      };
+    };
+  };
+in
+{
+  options.krebs.buildbot.master = api;
+  config = mkIf cfg.enable imp;
+}
diff --git a/krebs/3modules/buildbot/slave.nix b/krebs/3modules/buildbot/slave.nix
new file mode 100644
index 000000000..0e7796d8a
--- /dev/null
+++ b/krebs/3modules/buildbot/slave.nix
@@ -0,0 +1,186 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+let
+  buildbot-slave-init = pkgs.writeText "buildbot-slave.tac" ''
+    import os
+
+    from buildslave.bot import BuildSlave
+    from twisted.application import service
+
+    basedir = '${cfg.workDir}'
+    rotateLength = 10000000
+    maxRotatedFiles = 10
+
+    application = service.Application('buildslave')
+
+    from twisted.python.logfile import LogFile
+    from twisted.python.log import ILogObserver, FileLogObserver
+    logfile = LogFile.fromFullPath(os.path.join(basedir, "twistd.log"), rotateLength=rotateLength,
+                                  maxRotatedFiles=maxRotatedFiles)
+    application.setComponent(ILogObserver, FileLogObserver(logfile).emit)
+
+    buildmaster_host = '${cfg.masterhost}'
+    # TODO: masterport?
+    port = 9989
+    slavename = '${cfg.username}'
+    passwd = '${cfg.password}'
+    keepalive = 600
+    usepty = 0
+    umask = None
+    maxdelay = 300
+    allow_shutdown = None
+
+    ${cfg.extraConfig}
+
+    s = BuildSlave(buildmaster_host, port, slavename, passwd, basedir,
+                  keepalive, usepty, umask=umask, maxdelay=maxdelay,
+                  allow_shutdown=allow_shutdown)
+    s.setServiceParent(application)
+    '';
+  default-packages = [ pkgs.git pkgs.bash ];
+  cfg = config.krebs.buildbot.slave;
+
+  api = {
+    enable = mkEnableOption "Buildbot Slave";
+
+    workDir = mkOption {
+      default = "/var/lib/buildbot/slave";
+      type = types.str;
+      description = ''
+        Path to build bot slave directory.
+        Will be created on startup.
+      '';
+    };
+
+    masterhost = mkOption {
+      default = "localhost";
+      type = types.str;
+      description = ''
+        Hostname/IP of the buildbot master
+      '';
+    };
+
+    username = mkOption {
+      type = types.str;
+      description = ''
+        slavename used to authenticate with master
+      '';
+    };
+
+    password = mkOption {
+      type = types.str;
+      description = ''
+        slave password used to authenticate with master
+      '';
+    };
+
+    contact = mkOption {
+      default = "nix slave <buildslave@${config.networking.hostName}>";
+      type = types.str;
+      description = ''
+        contact to be announced by buildslave
+      '';
+    };
+
+    description = mkOption {
+      default = "Nix Generated BuildSlave";
+      type = types.str;
+      description = ''
+        description for hostto be announced by buildslave
+      '';
+    };
+
+    packages = mkOption {
+      default = [ pkgs.git ];
+      type = with types; listOf package;
+      description = ''
+        packages which should be in path for buildslave
+      '';
+    };
+
+    extraEnviron = mkOption {
+      default = {};
+      example = {
+        NIX_PATH = "nixpkgs=/path/to/my/nixpkgs";
+      };
+      type = types.attrsOf types.str;
+      description = ''
+        extra environment variables to be provided to the buildslave service
+        if you need nixpkgs, e.g. for running nix-shell you can set NIX_PATH here.
+      '';
+    };
+
+    extraConfig = mkOption {
+      default = "";
+      type = types.lines;
+      example = ''
+        port = 443
+        keepalive = 600
+      '';
+      description = ''
+        extra config evaluated before calling BuildSlave init in .tac file
+      '';
+    };
+  };
+
+  imp = {
+
+    users.extraUsers.buildbotSlave = {
+      uid = genid "buildbotSlave";
+      description = "Buildbot Slave";
+      home = cfg.workDir;
+      createHome = false;
+    };
+
+    users.extraGroups.buildbotSlave = {
+      gid = 1408105834;
+    };
+
+    systemd.services."buildbotSlave-${cfg.username}-${cfg.masterhost}" = {
+      description = "Buildbot Slave for ${cfg.username}@${cfg.masterhost}";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      path = default-packages ++ cfg.packages;
+
+      environment = {
+          SSL_CERT_FILE = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";
+          NIX_REMOTE="daemon";
+      } // cfg.extraEnviron;
+
+      serviceConfig = let
+        workdir = "${lib.shell.escape cfg.workDir}";
+        contact = "${lib.shell.escape cfg.contact}";
+        description = "${lib.shell.escape cfg.description}";
+        buildbot = pkgs.buildbot-slave;
+        # TODO:make this
+      in {
+        PermissionsStartOnly = true;
+        Type = "forking";
+        PIDFile = "${workdir}/twistd.pid";
+        # TODO: maybe also prepare buildbot.tac?
+        ExecStartPre = pkgs.writeScript "buildbot-master-init" ''
+          #!/bin/sh
+          set -efux
+          mkdir -p ${workdir}/info
+          cp ${buildbot-slave-init} ${workdir}/buildbot.tac
+          echo ${contact} > ${workdir}/info/admin
+          echo ${description} > ${workdir}/info/host
+
+          chown buildbotSlave:buildbotSlave -R ${workdir}
+          chmod 700 -R ${workdir}
+        '';
+        ExecStart = "${buildbot}/bin/buildslave start ${workdir}";
+        ExecStop = "${buildbot}/bin/buildslave stop ${workdir}";
+        PrivateTmp = "true";
+        User = "buildbotSlave";
+        Restart = "always";
+        RestartSec = "10";
+      };
+    };
+  };
+in
+{
+  options.krebs.buildbot.slave = api;
+  config = mkIf cfg.enable imp;
+}
diff --git a/krebs/3modules/default.nix b/krebs/3modules/default.nix
index dddb2df50..65c1aa2ec 100644
--- a/krebs/3modules/default.nix
+++ b/krebs/3modules/default.nix
@@ -7,8 +7,11 @@ let
   out = {
     imports = [
       ./apt-cacher-ng.nix
+      ./backup.nix
       ./bepasty-server.nix
       ./build.nix
+      ./buildbot/master.nix
+      ./buildbot/slave.nix
       ./current.nix
       ./exim-retiolum.nix
       ./exim-smarthost.nix
diff --git a/krebs/3modules/exim-retiolum.nix b/krebs/3modules/exim-retiolum.nix
index e1315d8c8..ea012c38c 100644
--- a/krebs/3modules/exim-retiolum.nix
+++ b/krebs/3modules/exim-retiolum.nix
@@ -1,14 +1,12 @@
 { config, pkgs, lib, ... }:
 
-with builtins;
 with lib;
 let
   cfg = config.krebs.exim-retiolum;
 
   out = {
     options.krebs.exim-retiolum = api;
-    config =
-      mkIf cfg.enable imp;
+    config = mkIf cfg.enable imp;
   };
 
   api = {
@@ -16,13 +14,13 @@ let
   };
 
   imp = {
-    services.exim =
-      # This configuration makes only sense for retiolum-enabled hosts.
-      # TODO modular configuration
-      assert config.krebs.retiolum.enable;
-      {
-        enable = true;
-        config = ''
+    services.exim = {
+      enable = true;
+      config =