Add :delivery_supermarket default source type

This type behaves like the supermarket/community source, except that
only the highest version cookbook is exposed via the universe graph.

lib/chef-dk/policyfile/cookbook_sources.rb

@@ -19,3 +19,4 @@
 require 'chef-dk/policyfile/community_cookbook_source'
 require 'chef-dk/policyfile/chef_server_cookbook_source'
 require 'chef-dk/policyfile/chef_repo_cookbook_source'
+require 'chef-dk/policyfile/delivery_supermarket_source'

lib/chef-dk/policyfile/delivery_supermarket_source.rb

@@ -0,0 +1,82 @@
+#
+# Copyright:: Copyright (c) 2014 Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'forwardable'
+
+require 'semverse'
+
+require 'chef-dk/policyfile/community_cookbook_source'
+
+module ChefDK
+  module Policyfile
+
+    # Fetches cookbooks from a supermarket, similar to CommunityCookbookSource
+    # (which it delegates to), except that only the latest versions of any
+    # cookbook can be used.
+    #
+    # This is intended to be used in an environment where the team wants to
+    # make only the newest version of a given cookbook available in order to
+    # force developers to integrate continuously at the component artifact
+    # (cookbook) level. To achieve this goal, two constraints must be imposed:
+    #
+    # * Cookbook changes pass through a Ci pipeline and are ultimately uploaded
+    #   to a private supermarket (or equivalent, i.e. mini-mart) after final
+    #   approval (which can be automated or not)
+    # * Version numbers for cookbooks that pass through the Ci pipeline always
+    #   increase over time (so that largest version number == newest)
+    #
+    # In the future, alternative approaches may be persued to achieve the goal
+    # of continuously integrating at the cookbook level without imposing those
+    # constraints.
+    #
+    class DeliverySupermarketSource
+
+      extend Forwardable
+
+      def_delegator :@community_source, :uri
+      def_delegator :@community_source, :source_options_for
+      def_delegator :@community_source, :null?
+
+      def initialize(uri)
+        @community_source = CommunityCookbookSource.new(uri)
+      end
+
+      def ==(other)
+        other.kind_of?(self.class) && other.uri == uri
+      end
+
+      def universe_graph
+        @universe_graph ||= begin
+          @community_source.universe_graph.inject({}) do |truncated, (cookbook_name, version_and_deps_list)|
+            sorted_versions = version_and_deps_list.keys.sort_by do |version_string|
+            Semverse::Version.new(version_string)
+          end
+          greatest_version = sorted_versions.last
+          truncated[cookbook_name] = { greatest_version => version_and_deps_list[greatest_version] }
+          truncated
+          end
+        end
+      end
+
+      def desc
+        "delivery_supermarket(#{uri})"
+      end
+
+    end
+  end
+end
+

lib/chef-dk/policyfile/dsl.rb

@@ -73,6 +73,8 @@ def default_source(source_type = nil, source_argument = nil)
         case source_type
         when :community, :supermarket
           set_default_community_source(source_argument)
+        when :delivery_supermarket
+          set_default_delivery_supermarket_source(source_argument)
         when :chef_server
           set_default_chef_server_source(source_argument)
         when :chef_repo
@@ -143,6 +145,14 @@ def set_default_community_source(source_uri)
         set_default_source(CommunityCookbookSource.new(source_uri))
       end
 
+      def set_default_delivery_supermarket_source(source_uri)
+        if source_uri.nil?
+          @errors << "You must specify the server's URI when using a default_source :delivery_supermarket"
+        else
+          set_default_source(DeliverySupermarketSource.new(source_uri))
+        end
+      end
+
       def set_default_chef_server_source(source_uri)
         if source_uri.nil?
           @errors << "You must specify the server's URI when using a default_source :chef_server"

spec/unit/policyfile/delivery_supermarket_source_spec.rb

@@ -0,0 +1,105 @@
+#
+# Copyright:: Copyright (c) 2014 Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'spec_helper'
+require 'chef-dk/policyfile/delivery_supermarket_source'
+
+describe ChefDK::Policyfile::DeliverySupermarketSource do
+
+  let(:supermarket_uri) { "https://delivery-supermarket.example" }
+
+  subject(:cookbook_source) { ChefDK::Policyfile::DeliverySupermarketSource.new(supermarket_uri) }
+
+  let(:http_connection) { double("Chef::HTTP::Simple") }
+
+  let(:universe_response_encoded) { IO.read(File.join(fixtures_path, "cookbooks_api/small_universe.json")) }
+
+  let(:truncated_universe) do
+    {
+      "nginx" => {
+        "2.7.4" => {
+          "apt" => "~> 2.2.0",
+          "bluepill" => "~> 2.3.0",
+          "build-essential" => "~> 2.0.0",
+          "ohai" => "~> 2.0.0",
+          "runit" => "~> 1.2.0",
+          "yum-epel" => "~> 0.3.0"
+        }
+      },
+      "mysql" => {
+        "5.3.6" => {
+          "yum-mysql-community" => ">= 0.0.0"
+        }
+      },
+      "application" => {
+        "4.1.4" => {}
+      },
+      "database" => {
+        "2.2.0" => {
+          "mysql" => ">= 5.0.0",
+          "postgresql" => ">= 1.0.0",
+          "aws" => ">= 0.0.0",
+          "xfs" => ">= 0.0.0",
+          "mysql-chef_gem" => ">= 0.0.0"
+        }
+      },
+      "postgresql" => {
+        "3.4.1" => {
+          "apt" => ">= 1.9.0",
+          "build-essential" => ">= 0.0.0",
+          "openssl" => ">= 0.0.0"
+        }
+      },
+      "apache2" => {
+        "1.10.4" => {
+          "iptables" => ">= 0.0.0",
+          "logrotate" => ">= 0.0.0",
+          "pacman" => ">= 0.0.0"
+        }
+      },
+      "apt" => { "2.4.0" => {}},
+      "yum" => { "3.2.2" => {}}
+    }
+  end
+
+  it "uses `delivery_supermarket` it its description" do
+    expect(cookbook_source.desc).to eq("delivery_supermarket(https://delivery-supermarket.example)")
+  end
+
+  describe "when fetching the /universe graph" do
+
+    before do
+      expect(Chef::HTTP::Simple).to receive(:new).with(supermarket_uri).and_return(http_connection)
+      expect(http_connection).to receive(:get).with("/universe").and_return(universe_response_encoded)
+    end
+
+    it "fetches the universe graph and truncates to only the latest versions" do
+      actual_universe = cookbook_source.universe_graph
+      expect(actual_universe).to have_key("apt")
+      expect(actual_universe["apt"]).to eq(truncated_universe["apt"])
+      expect(cookbook_source.universe_graph).to eq(truncated_universe)
+    end
+
+    it "generates location options for a cookbook from the given graph" do
+      expected_opts = { artifactserver: "https://supermarket.chef.io/api/v1/cookbooks/apache2/versions/1.10.4/download", version: "1.10.4" }
+      expect(cookbook_source.source_options_for("apache2", "1.10.4")).to eq(expected_opts)
+    end
+
+  end
+
+end
+

spec/unit/policyfile_evaluation_spec.rb

@@ -226,6 +226,42 @@
 
       end
 
+      context "with the default source set to a delivery_supermarket" do
+
+        context "when no URI is given" do
+
+          let(:policyfile_rb) do
+            <<-EOH
+              run_list "foo", "bar"
+              default_source :delivery_supermarket
+            EOH
+          end
+
+          it "errors out with a message that the supermarket URI is required" do
+            expect(policyfile.errors).to eq([ "You must specify the server's URI when using a default_source :delivery_supermarket" ])
+          end
+
+        end
+
+        context "when the URI is given" do
+
+          let(:policyfile_rb) do
+            <<-EOH
+              run_list "foo", "bar"
+              default_source :delivery_supermarket, "https://supermarket.example.com"
+            EOH
+          end
+
+          it "sets the default source to the delivery_supermarket" do
+            expect(policyfile.errors).to eq([])
+            expected = [ ChefDK::Policyfile::DeliverySupermarketSource.new("https://supermarket.example.com") ]
+            expect(policyfile.default_source).to eq(expected)
+          end
+
+        end
+
+      end
+
       context "with the default source set to a chef server" do
 
         let(:policyfile_rb) do