Add node.chef_environment attr to node

chef_environment must be a non-blank string or nil.  To follow the
getter/setter pattern that facilitates setting values in the DSL
without '=', we introduce a NIL_ARGUMENT constant to use instead of
nil for the getter case.

Author: Seth Falcon

chef/lib/chef.rb

@@ -17,7 +17,7 @@
 #
 
 require 'chef/version'
-
+require 'chef/nil_argument'
 require 'extlib'
 require 'chef/exceptions'
 require 'chef/log'

chef/lib/chef/nil_argument.rb

@@ -0,0 +1,3 @@
+class Chef
+  NIL_ARGUMENT = Object.new
+end

chef/lib/chef/node.rb

@@ -21,6 +21,7 @@
 
 require 'chef/config'
 require 'chef/cookbook/cookbook_collection'
+require 'chef/nil_argument'
 require 'chef/mixin/check_helper'
 require 'chef/mixin/params_validate'
 require 'chef/mixin/from_file'
@@ -78,7 +79,7 @@ class Node
           "map" => <<-EOJS
             function(doc) {
               if (doc.chef_type == "node") {
-                var to_emit = { "name": doc.name };
+                var to_emit = { "name": doc.name, "chef_environment": doc.chef_environment };
                 if (doc["attributes"]["fqdn"]) {
                   to_emit["fqdn"] = doc["attributes"]["fqdn"];
                 } else {
@@ -138,7 +139,8 @@ class Node
     # Create a new Chef::Node object.
     def initialize(couchdb=nil)
       @name = nil
-      
+
+      @chef_environment = nil
       @normal_attrs = Mash.new
       @override_attrs = Mash.new
       @default_attrs = Mash.new
@@ -206,6 +208,23 @@ def name(arg=nil)
       end
     end
 
+    def chef_environment(arg=Chef::NIL_ARGUMENT)
+      if arg != Chef::NIL_ARGUMENT
+        if arg.nil?
+          @chef_environment = nil
+        else
+          validate(
+                   {:name => arg },
+                   {:name => { :kind_of => String,
+                       :cannot_be => :blank}
+                   })
+          @chef_environment = arg
+        end
+      else
+        @chef_environment
+      end
+    end
+
     # Used by the DSL
     def attribute
       construct_attributes
@@ -425,6 +444,7 @@ def to_hash
       index_hash = Hash.new
       index_hash["chef_type"] = "node"
       index_hash["name"] = name
+      index_hash["chef_environment"] = chef_environment
       attribute.each do |key, value|
         index_hash[key] = value
       end
@@ -438,6 +458,7 @@ def to_hash
     def to_json(*a)
       result = {
         "name" => name,
+        "chef_environment" => chef_environment,
         'json_class' => self.class.name,
         "automatic" => automatic_attrs,
         "normal" => normal_attrs,
@@ -454,7 +475,7 @@ def to_json(*a)
     def self.json_create(o)
       node = new
       node.name(o["name"])
-
+      node.chef_environment(o["chef_environment"])
       if o.has_key?("attributes")
         node.normal_attrs = o["attributes"]
       end

chef/spec/data/nodes/test.example.com.rb

@@ -13,3 +13,5 @@
 # Nodes should have recipes
 ##
 recipes "operations-master", "operations-monitoring"
+
+chef_environment "dev"

chef/spec/unit/node_spec.rb

@@ -96,8 +96,33 @@
 
   end
 
-  describe "when modifying Node attributes" do
-    it "loads attributes from cookbooks" do
+  describe "chef_environment" do
+    it "should set an environment with chef_environment(something)" do
+      lambda { @node.chef_environment("latte") }.should_not raise_error
+    end
+    
+    it "should return the chef_environment with chef_environment()" do
+      @node.chef_environment("latte")
+      @node.chef_environment.should == "latte"
+    end
+    
+    it "should disallow non-strings (except for nil)" do
+      lambda { @node.chef_environment(Hash.new) }.should raise_error(ArgumentError)
+    end
+
+    it "can be nil" do
+      @node.chef_environment("foo")
+      @node.chef_environment(nil)
+      @node.chef_environment.should == nil
+    end
+    
+    it "cannot be blank" do
+      lambda { @node.chef_environment("")}.should raise_error(Chef::Exceptions::ValidationFailed)
+    end
+  end
+
+  describe "attributes" do
+    it "should be loaded from the node's cookbooks" do
       Chef::Config.cookbook_path = File.expand_path(File.join(File.dirname(__FILE__), "..", "data", "cookbooks"))
       @node.cookbook_collection = Chef::CookbookCollection.new(Chef::CookbookLoader.new)
       @node.load_attributes
@@ -439,6 +464,7 @@
     it "should load a node from a file by fqdn" do
       @node.find_file("test.example.com")
       @node.name.should == "test.example.com"
+      @node.chef_environment.should == "dev"
     end
 
     it "should load a node from a file by hostname" do
@@ -467,6 +493,7 @@
 
   describe "to_hash" do
     it "should serialize itself as a hash" do
+      @node.chef_environment("dev")
       @node.default_attrs = { "one" => { "two" => "three", "four" => "five", "eight" => "nine" } }
       @node.override_attrs = { "one" => { "two" => "three", "four" => "six" } }
       @node.normal_attrs = { "one" => { "two" => "seven" } }
@@ -482,6 +509,7 @@
       h["run_list"].should be_include("role[marxist]")
       h["run_list"].should be_include("role[leninist]")
       h["run_list"].should be_include("recipe[stalinist]")
+      h["chef_environment"].should == "dev"
     end
   end
 
@@ -491,6 +519,7 @@
       json = @node.to_json()
       json.should =~ /json_class/
       json.should =~ /name/
+      json.should =~ /chef_environment/
       json.should =~ /normal/
       json.should =~ /default/
       json.should =~ /override/
@@ -503,6 +532,7 @@
       serialized_node = JSON.parse(json)
       serialized_node.should be_a_kind_of(Chef::Node)
       serialized_node.name.should eql(@node.name)
+      serialized_node.chef_environment.should eql(@node.chef_environment)
       @node.each_attribute do |k,v|
         serialized_node[k].should eql(v)
       end