Nix shell for RabbitMQ under $PWD with metronome plugin

rabbitmq.nix

with import <nixpkgs> {};
let dependencies = rec {
  _rabbitmq_plugins = stdenv.mkDerivation rec {
    name = "rabbitmq-plugins-${version}";
    version = rabbitmq_server.version;
    buildInputs = [ git python libxslt mercurial erlangR16 zip unzip ];
    unpackPhase = "";
    builder = builtins.toFile "builder.sh" ''
source $stdenv/setup
git clone https://github.com/rabbitmq/rabbitmq-public-umbrella                  
cd rabbitmq-public-umbrella                                                     
git checkout rabbitmq_v`echo $version|sed -e 's/\./_/g'`
make co
make BRANCH=rabbitmq_v`echo $version|sed -e 's/\./_/g'` up_c
rm -rf rabbitmq-amqp1.0  # BUILD BROKEN
PLUGINS_DIST_DIR=$out make plugins-dist
make -C rabbitmq-metronome dist
cp rabbitmq-metronome/dist/*.ez $out
    '';
    SSL_CERT_FILE = "${cacert}/etc/ssl/certs/ca-bundle.crt";
  };
  _rabbitmq_config = builtins.toFile "rabbitmq.config" ''[
  {rabbit, [
    {vm_memory_high_watermark, 0.5},
    {disk_free_limit, 100000000}
  ]},
  {rabbitmq_management, [
    {load_definitions, "${_rabbitmq_json}"}
  ]}
].'';
  _enabled_plugins = builtins.toFile "enabled_plugins" "[
  rabbitmq_management,rabbitmq_metronome
].";
  _rabbitmq_json = builtins.toFile "rabbitmq.json" ''{
  "users": [{
    "tags": "administrator",
    "name": "guest",
    "password": "guest"
  }],
  "vhosts": [
    {"name": "/"}
  ],
  "permissions": [{
    "write": ".*",
    "vhost": "/",
    "read": ".*",
    "user": "guest",
    "configure": ".*"
  }]
}'';
};
in with dependencies;
stdenv.mkDerivation {
  name = "env";
  buildInputs = [
    (rabbitmq_server.override { erlang = erlangR16; })
  ];
  shellHook = ''
    export SSL_CERT_FILE=${cacert}/etc/ssl/certs/ca-bundle.crt
    mkdir -p .rabbitmq_server
    mkdir -p .rabbitmq_server/mnesia
    export RABBITMQ_LOG_BASE=`pwd`/.rabbitmq_server
    export RABBITMQ_MNESIA_BASE=`pwd`/.rabbitmq_server/mnesia
    export RABBITMQ_PLUGINS_DIR=${_rabbitmq_plugins}
    export RABBITMQ_ENABLED_PLUGINS_FILE=${_enabled_plugins}
    export RABBITMQ_CONFIG_FILE=`echo ${_rabbitmq_config}|sed "s/.config//"`
  '';
}