Example cloudformation template for auto scaling deploys

cloudformation.json

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Description": "Auto scaling deploy example",
  "Parameters": {
    "AvailabilityZone": {
      "Type": "String",
      "Default": "us-west-1a"
    },
    "ImageId": {
      "Type": "String"
    }
  },
  "Resources": {
    "VPC": {
      "Type": "AWS::EC2::VPC",
      "Properties": {
        "CidrBlock": "10.0.0.0/16",
        "EnableDnsSupport": true,
        "EnableDnsHostnames": true
      }
    },
    "InternetGateway": {
      "Type": "AWS::EC2::InternetGateway",
      "Properties": {}
    },
    "VPCGatewayAttachment": {
      "Type": "AWS::EC2::VPCGatewayAttachment",
      "Properties": {
        "InternetGatewayId": {
          "Ref": "InternetGateway"
        },
        "VpcId": {
          "Ref": "VPC"
        }
      }
    },
    "PublicSubnet": {
      "Type": "AWS::EC2::Subnet",
      "Properties": {
        "AvailabilityZone": {
          "Ref": "AvailabilityZone"
        },
        "CidrBlock": "10.0.0.0/24",
        "VpcId": {
          "Ref": "VPC"
        },
        "Tags": [
          {
            "Key": "Name",
            "Value": "Public"
          }
        ]
      }
    },
    "PublicRouteTable": {
      "Type": "AWS::EC2::RouteTable",
      "Properties": {
        "VpcId": {
          "Ref": "VPC"
        },
        "Tags": [
          {
            "Key": "Name",
            "Value": "Public"
          }
        ]
      }
    },
    "OutboundConnectionRoute": {
      "Type": "AWS::EC2::Route",
      "Properties": {
        "DestinationCidrBlock": "0.0.0.0/0",
        "GatewayId": {
          "Ref": "InternetGateway"
        },
        "RouteTableId": {
          "Ref": "PublicRouteTable"
        }
      }
    },
    "PublicSubnetRouteTableAssociation": {
      "Type": "AWS::EC2::SubnetRouteTableAssociation",
      "Properties": {
        "RouteTableId": {
          "Ref": "PublicRouteTable"
        },
        "SubnetId": {
          "Ref": "PublicSubnet"
        }
      }
    },
    "WebServerSG": {
      "Type": "AWS::EC2::SecurityGroup",
      "Properties": {
        "VpcId": {
          "Ref": "VPC"
        },
        "GroupDescription": "Allows inbound http traffic",
        "SecurityGroupIngress": [
          {
            "CidrIp": "0.0.0.0/0",
            "FromPort": 80,
            "IpProtocol": "tcp",
            "ToPort": 80
          }
        ],
        "Tags": [
          {
            "Key": "Name",
            "Value": "http"
          }
        ]
      }
    },
    "LoadBalancer": {
      "Type": "AWS::ElasticLoadBalancing::LoadBalancer",
      "Properties": {
        "LoadBalancerName": "LoadBalancer",
        "Listeners": [
          {
            "InstancePort": 80,
            "InstanceProtocol": "HTTP",
            "LoadBalancerPort": 80,
            "Protocol": "HTTP"
          }
        ],
        "Scheme": "internet-facing",
        "SecurityGroups": [
          {
            "Ref": "WebServerSG"
          }
        ],
        "Subnets": [
          {
            "Ref": "PublicSubnet"
          }
        ]
      }
    },
    "AppLaunchConfiguration": {
      "Type": "AWS::AutoScaling::LaunchConfiguration",
      "Properties": {
        "AssociatePublicIpAddress": true,
        "ImageId": {
          "Ref": "ImageId"
        },
        "InstanceType": "t2.micro",
        "SecurityGroups": []
      },
      "DependsOn": "VPCGatewayAttachment"
    },
    "AppASG": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "Properties": {
        "AvailabilityZones": [
          {
            "Ref": "AvailabilityZone"
          }
        ],
        "DesiredCapacity": 1,
        "LaunchConfigurationName": {
          "Ref": "AppLaunchConfiguration"
        },
        "LoadBalancerNames": [
          {
            "Ref": "LoadBalancer"
          }
        ],
        "MaxSize": 2,
        "MinSize": 1,
        "VPCZoneIdentifier": [
          {
            "Ref": "PublicSubnet"
          }
        ]
      },
      "UpdatePolicy": {
        "AutoScalingRollingUpdate": {
          "MinInstancesInService": 1
        }
      }
    }
  }
}