{
  "AWSTemplateFormatVersion" : "2010-09-09",

  "Description" : "AWS CloudFormation Cross-Stack Reference Sample Template: Demonstrates how to reference resources from a different stack. This template provisions an EC2 instance in an EC2 Security Group provisioned in a different stack. **WARNING** This template creates an Amazon EC2 instance. You will be billed for the AWS resources used if you create a stack from this template.",

  "Parameters": {
    "NetworkStackName": {
      "Description": "Name of an active CloudFormation stack that contains the networking resources, such as the subnet and security group, that will be used in this stack.",
      "Type": "String",
      "MinLength" : 1,
      "MaxLength" : 255,
      "AllowedPattern" : "^[a-zA-Z][-a-zA-Z0-9]*$",
      "Default" : "SampleNetworkCrossStack"
    }
  },

  "Mappings" : {
    "AWSRegionArch2AMI" : {
      "us-east-1"        : {"PV64" : "ami-8ff710e2", "HVM64" : "ami-f5f41398", "HVMG2" : "ami-4afd1d27"},
      "us-west-2"        : {"PV64" : "ami-eff1028f", "HVM64" : "ami-d0f506b0", "HVMG2" : "ami-ee897b8e"},
      "us-west-1"        : {"PV64" : "ami-ac85fbcc", "HVM64" : "ami-6e84fa0e", "HVMG2" : "ami-69106909"},
      "eu-west-1"        : {"PV64" : "ami-23ab2250", "HVM64" : "ami-b0ac25c3", "HVMG2" : "ami-936de5e0"},
      "eu-central-1"     : {"PV64" : "ami-27c12348", "HVM64" : "ami-d3c022bc", "HVMG2" : "ami-8e7092e1"},
      "ap-northeast-1"   : {"PV64" : "ami-26160d48", "HVM64" : "ami-29160d47", "HVMG2" : "ami-91809aff"},
      "ap-northeast-2"   : {"PV64" : "NOT_SUPPORTED", "HVM64" : "ami-cf32faa1", "HVMG2" : "NOT_SUPPORTED"},
      "ap-southeast-1"   : {"PV64" : "ami-f3dd0a90", "HVM64" : "ami-1ddc0b7e", "HVMG2" : "ami-3c30e75f"},
      "ap-southeast-2"   : {"PV64" : "ami-8f94b9ec", "HVM64" : "ami-0c95b86f", "HVMG2" : "ami-543d1137"},
      "sa-east-1"        : {"PV64" : "ami-e188018d", "HVM64" : "ami-fb890097", "HVMG2" : "NOT_SUPPORTED"},
      "cn-north-1"       : {"PV64" : "ami-77a46e1a", "HVM64" : "ami-05a66c68", "HVMG2" : "NOT_SUPPORTED"}
    }
  },

  "Resources" : {
    "WebServerInstance": {
      "Type": "AWS::EC2::Instance",
      "Metadata" : {
        "AWS::CloudFormation::Init" : {
          "configSets" : {
            "All" : [ "ConfigureSampleApp" ]
          },

          "ConfigureSampleApp" : {
            "packages" : {
              "yum" : {
                "httpd" : []
              }
            },

            "files" : {
              "/var/www/html/index.html" : {
                "content" : { "Fn::Join" : ["\n", [
                  "<img src=\"https://s3.amazonaws.com/cloudformation-examples/cloudformation_graphic.png\" alt=\"AWS CloudFormation Logo\"/>",
                  "<h1>Congratulations, you have successfully launched the AWS CloudFormation sample.</h1>"
                ]]},
                "mode"    : "000644",
                "owner"   : "root",
                "group"   : "root"
              }
            },

            "services" : {
              "sysvinit" : {
                "httpd"    : { "enabled" : "true", "ensureRunning" : "true" }
              }
            }
          }
        }
      },
      "Properties": {
        "InstanceType"   : "t2.micro",
        "ImageId": { "Fn::FindInMap": [ "AWSRegionArch2AMI", { "Ref": "AWS::Region" } , "HVM64" ] },
        "NetworkInterfaces" : [{
          "GroupSet"                 : [{ "Fn::ImportValue" :  {"Fn::Sub": "${NetworkStackName}-SecurityGroupID" } }],
          "AssociatePublicIpAddress" : "true",
          "DeviceIndex"              : "0",
          "DeleteOnTermination"      : "true",
          "SubnetId"                 : { "Fn::ImportValue" : {"Fn::Sub": "${NetworkStackName}-SubnetID" } }
        }],
        "UserData"       : { "Fn::Base64" : { "Fn::Join" : ["", [
             "#!/bin/bash -xe\n",
             "yum update -y aws-cfn-bootstrap\n",

             "# Install the files and packages from the metadata\n",
             "/opt/aws/bin/cfn-init -v ",
             "         --stack ", { "Ref" : "AWS::StackName" },
             "         --resource WebServerInstance ",
             "         --configsets All ",
             "         --region ", { "Ref" : "AWS::Region" }, "\n",

             "# Signal the status from cfn-init\n",
             "/opt/aws/bin/cfn-signal -e $? ",
             "         --stack ", { "Ref" : "AWS::StackName" },
             "         --resource WebServerInstance ",
             "         --region ", { "Ref" : "AWS::Region" }, "\n"
        ]]}}
      },
      "CreationPolicy" : {
        "ResourceSignal" : {
          "Timeout" : "PT5M"
        }
      }
    }
  },

  "Outputs" : {
    "URL" : {
      "Description" : "URL of the sample website",
      "Value" :  { "Fn::Join" : [ "", [ "http://", { "Fn::GetAtt" : [ "WebServerInstance", "PublicDnsName" ]}]]}
    }
  }
}