anchor.diff:        "Type" : "String",
         "Default": "Chef Server for SkyHopper"
       },
  +    "VpcId": {
  +      "Description" : "For VPC security groups without a default VPC (optional)",
  +      "Type" : "String"
  +    },
  +    "SubnetId": {
  +      "Description" : "The ID of the subnet that you want to launch the instance into (optional)",
  +      "Type" : "String"
  +    },
   
       "ChefPackageURL": { "Type" : "String", "Default": "https://packages.chef.io/stable/el/6/chef-server-core-12.6.0-1.el6.x86_64.rpm" },
       "ChefUser":       { "Type" : "String", "Default": "skyhopper" },
  
positive.code:     "RegionMap": <%= fragment(:ami_mappings) %>
    },
  
    "Resources" : {
      "SecurityGroup" : {
        "Type" : "AWS::EC2::SecurityGroup",
        "Properties" : {
          "GroupDescription" : "Enable SSH/HTTP/HTTPS",
          "SecurityGroupIngress" : [{
            "IpProtocol" : "tcp",
  
negative.code:     "EC2Instance" : {
        "Type" : "AWS::EC2::Instance",
        "Properties" : {
          "SubnetId" : {"Fn::If": ["HasSubnetId", {"Ref": "SubnetId"}, {"Ref": "AWS::NoValue"}]},
          "InstanceType" : { "Ref" : "InstanceType" },
          "KeyName" : { "Ref" : "KeyName" },
          "ImageId" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "AMI" ]},
  