Fixing Server.set_metadata

- Fixes the set_metadata method and adopts a better format for it.
- This should not be a breaking change since the method appears to have never worked since 2.0 :(
- Adding a test for it so it gets caught by CI in the future

Fixes #329

lib/fog/compute/google/models/server.rb

@@ -350,15 +350,25 @@ def set_scheduling(async = true,
           reload
         end
 
+        # Set an instance metadata
+        #
+        # @param [Bool] async Perform the operation asyncronously
+        # @param [Hash] new_metadata A new metadata object
+        #   Format: {'foo' => 'bar', 'baz'=>'foo'}
+        #
+        # @returns [Fog::Compute::Google::Server] server object
         def set_metadata(new_metadata = {}, async = true)
           requires :identity, :zone
 
-          if new_metadata[:items] && new_metadata[:items].is_a?(Hash)
-            new_metadata[:items] = new_metadata[:items].map { |k, v| { :key => k, :value => v } }
+          unless new_metadata.is_a?(Hash)
+            raise Fog::Errors::Error.new("Instance metadata should be a hash")
           end
 
+          # If metadata is presented in {'foo' => 'bar', 'baz'=>'foo'}
+          new_metadata_items = new_metadata.each.map { |k, v| { :key => k.to_s, :value => v.to_s } }
+
           data = service.set_server_metadata(
-            identity, zone_name, metadata[:fingerprint], new_metadata
+            identity, zone_name, metadata[:fingerprint], new_metadata_items
           )
           operation = Fog::Compute::Google::Operations
                       .new(:service => service)

lib/fog/compute/google/requests/set_server_metadata.rb

@@ -18,6 +18,8 @@ class Real
         #     instance.reload
         #     fingerprint = instance.metadata['fingerprint']
         # @param [Hash] metadata A new metadata object
+        #   Should have the following structure:
+        #   {:items=>[{:key=>"foo", :value=>"bar"}, {:key=>"baz", :value=>"foo"}]}
         #
         # @returns [::Google::Apis::ComputeV1::Operation] set operation
         def set_server_metadata(instance, zone, fingerprint, metadata_items = [])

test/integration/compute/test_servers.rb

@@ -4,8 +4,17 @@
 class TestServers < FogIntegrationTest
   include TestCollection
 
+  # Cleanup is handled by TestCollection
   def setup
     @subject = Fog::Compute[:google].servers
     @factory = ServersFactory.new(namespaced_name)
   end
+
+  def test_set_metadata
+    server = @factory.create
+    server.wait_for { ready? }
+    server.set_metadata({ "foo" => "bar", "baz" => "foo" }, false)
+    assert_equal [{ :key => "foo", :value => "bar" },
+                  { :key=>"baz", :value=>"foo" }], server.metadata[:items]
+  end
 end