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

  "Description" : "Template Description",

  "Parameters" : {
    "InstanceType" : {
      "Description" : "Type of instance to launch (Note: The AMI is a 32bit AMI, so the instance must be capable of running a 32bit image)",
      "Type" : "String",
      "Default" : "m1.small"
    },
    "WebServerPort" : {
      "Description" : "The TCP port for the Web Server",
      "Type" : "String",
      "Default" : "8888"
    },
    "KeyPair" : {
      "Description" : "The EC2 Key Pair to allow SSH access to the instances",
      "Type" : "String",
      "Default" : "FooBar"
    }
  },

  "Mappings" : {
    "RegionMap" : {
      "us-east-1" : {
          "TestAZ" : "us-east-1a",
          "AMI" : "ami-e08f7f89"
      },
      "us-west-1" : {
          "TestAZ" : "us-west-1a",
          "AMI" : "ami-a38bdbe6"
      },
      "eu-west-1" : {
          "TestAZ" : "eu-west-1a",
          "AMI" : "ami-03310577"
      },
      "ap-northeast-1" : {
          "TestAZ" : "ap-northeast-1a",
          "AMI" : "ami-e2a3ddb0"
      }
    }
  },

  "Resources" : {
    "WebServerGroup" : {
      "Type" : "AWS::AutoScaling::AutoScalingGroup",
      "Properties" : {
        "AvailabilityZones" : [ { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "TestAZ" ]} ],
        "LaunchConfigurationName" : { "Ref" : "LaunchConfig" },
        "MinSize" : "2",
        "MaxSize" : "2",
        "LoadBalancerNames" : [ { "Ref" : "ElasticLoadBalancer" } ]
      }
    },

    "LaunchConfig" : {
      "Type" : "AWS::AutoScaling::LaunchConfiguration",
      "Properties" : {
        "KeyName" : { "Ref" : "KeyPair" },
        "ImageId" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "AMI" ]},
        "UserData" : { "Fn::Base64" : { "Fn::Join" : [ ":", [ { "Ref" : "WebServerPort" }]]}},
        "SecurityGroups" : [ { "Ref" : "InstanceSecurityGroup" } ],
        "InstanceType" : { "Ref" : "InstanceType" }
      }
    },

    "ElasticLoadBalancer" : {
      "Type" : "AWS::ElasticLoadBalancing::LoadBalancer",
      "Properties" : {
        "AvailabilityZones" : [ { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "TestAZ" ]} ],
        "Listeners" : [ {
          "LoadBalancerPort" : "80",
          "InstancePort" : { "Ref" : "WebServerPort" },
          "Protocol" : "HTTP"
        } ],
        "HealthCheck" : {
          "Target" : { "Fn::Join" : [ "", ["HTTP:", { "Ref" : "WebServerPort" }, "/"]]},
          "HealthyThreshold" : "3",
          "UnhealthyThreshold" : "5",
          "Interval" : "30",
          "Timeout" : "5"
        }
      }
    },

    "InstanceSecurityGroup" : {
      "Type" : "AWS::EC2::SecurityGroup",
      "Properties" : {
        "GroupDescription" : "Enable SSH access and HTTP access on the inbound port",
        "SecurityGroupIngress" : [ {
          "IpProtocol" : "tcp",
          "FromPort" : "22",
          "ToPort" : "22",
          "CidrIp" : "0.0.0.0/0"
        },
        {
          "IpProtocol" : "tcp",
          "FromPort" : { "Ref" : "WebServerPort" },
          "ToPort" : { "Ref" : "WebServerPort" },
          "CidrIp" : "0.0.0.0/0"
        } ]
      }
    }
  },

  "Outputs" : {
    "URL" : {
      "Description" : "The URL of the Load Balanced Web Site",
      "Value" :  { "Fn::Join" : [ "", [ "http://", { "Fn::GetAtt" : [ "ElasticLoadBalancer", "DNSName" ]}]]}
    }
  }
}