Merge pull request #1334 from mikehale/asg-next-token

[AWS|cloud_watch] Add Metrics#each, which follows NextToken

lib/fog/aws/models/cloud_watch/metrics.rb

@@ -6,11 +6,31 @@ module Fog
     class CloudWatch
 
       class Metrics < Fog::Collection
+        attribute :next_token, :aliases => 'NextToken'
+
         model Fog::AWS::CloudWatch::Metric
 
         def all(conditions={})
-          data = connection.list_metrics(conditions).body['ListMetricsResult']['Metrics']
+          result = connection.list_metrics(conditions).body['ListMetricsResult']
-          load(data) # data is an array of attribute hashes
+          merge_attributes("NextToken" => result["NextToken"])
+          load(result['Metrics']) # an array of attribute hashes
+        end
+
+        alias :each_metric_this_page :each
+        def each
+          if !block_given?
+            self
+          else
+            subset = dup.all
+            subset.each_metric_this_page {|m| yield m }
+
+            while next_token = subset.next_token
+              subset = subset.all("NextToken" => next_token)
+              subset.each_metric_this_page {|m| yield m }
+            end
+            
+            self
+          end
         end
 
         def get(namespace, metric_name, dimensions=nil)

lib/fog/aws/requests/cloud_watch/list_metrics.rb

@@ -33,6 +33,33 @@ module Fog
         end
 
       end
+
+      class Mock
+        def list_metrics(options={})
+          body = case options["NextToken"]
+                 when nil
+                   { "ListMetricsResult" => {
+                      "Metrics" => (0...500).map{ {} },
+                      "NextToken" => '1'
+                   }}
+                 when "1"
+                   { "ListMetricsResult" => {
+                      "Metrics" => (0...500).map{ {} },
+                      "NextToken" => '2'
+                   }}
+                 when "2"
+                   { "ListMetricsResult" => {
+                      "Metrics" => (0...1).map{ {} }
+                   }}
+                 end
+
+          Excon::Response.new.tap do |response|
+            response.body = body
+            response.status = 200
+          end
+        end
+      end
+
     end
   end
 end

tests/aws/models/cloud_watch/metrics_tests.rb

@@ -14,4 +14,19 @@ Shindo.tests("AWS::CloudWatch | metrics", ['aws', 'cloudwatch']) do
     
   end
 
+  tests('#each') do
+    Fog.mock!
+    tests("handle NextToken").returns(1001) do
+      count = 0      
+      Fog::AWS[:cloud_watch].metrics.each {|e| count += 1 }
+      count
+    end
+
+    tests("yields Metrics instances").succeeds do
+      all = []
+      Fog::AWS[:cloud_watch].metrics.each {|e| all << e }
+      all.all? {|e| e.is_a?(Fog::AWS::CloudWatch::Metric) }
+    end
+  end
+
 end