Download and install Zookeeper

.gitignore

@@ -2,3 +2,4 @@
 .bundle
 Gemfile.lock
 pkg/*
+tmp/*

README.md

@@ -8,4 +8,10 @@ Prerequisites
 
 DCell requires 0MQ. On OS X, this is available through Homebrew by running:
 
-  brew install zeromq
+  brew install zeromq
+
+DCell also requires Zookeeper. For production, you will need to install and
+maintain your own Zookeeper cluster. For development, you can run the
+following to download and install Zookeeper:
+
+  rake zookeeper:install

tasks/zookeeper.task

@@ -0,0 +1,24 @@
+require 'rake/clean'
+
+namespace :zookeeper do
+  VERSION = "3.3.3"
+  TARBALL = "zookeeper-#{VERSION}.tar.gz"
+
+  task :download => "tmp/#{TARBALL}"
+  directory 'tmp'
+
+  file "tmp/#{TARBALL}" => "tmp" do
+    puts "*** Downloading Zookeeper"
+    sh "curl http://www.carfab.com/apachesoftware/zookeeper/stable/#{TARBALL} -o tmp/#{TARBALL}"
+  end
+
+  task :install => :download do
+    puts "*** Unpacking Zookeeper"
+
+    rm_rf "zookeeper" if File.exists? "zookeeper"
+    sh "tar -zxvf tmp/#{TARBALL}"
+    mv "zookeeper-#{VERSION}", "zookeeper"
+  end
+end
+
+CLEAN.include "tmp", "zookeeper"