cfn_template

AWSCloudFormationInit produces the value of the AWS::CloudFormation::Init type and should be placed on the Metadata of a AWS::EC2::Instance or AWS::AutoScale::LaunchConfiguration It works with the UserData field of a AWS::AutoScale::LaunchConfiguration (or AWS::EC2::Instance) to bootstrap an EC2 instance when it's created Example use: { "Resources": { "AutoScalingLaunchConfiguration": { "Type": "AWS::AutoScaling::LaunchConfiguration", "Metadata": { "AWS::CloudFormation::Init": {{ .Resources.AutoScaling.LaunchConfiguration.Metadata.AWSCloudFormationInit }} }, "Properties": { "UserData": {{ .Resources.AutoScaling.LaunchConfiguration.UserData }} } } } }.

Allow EC2 instances to receive traffic from the provisioned ELB.

ImageIdInMap works with a mapping like the following to select an AMI id for the current region { "Mappings": { "RegionToAmazonLinuxAMI": { "ap-northeast-1": { "Key": "ami-1c1b9f1c" }, "ap-southeast-1": { "Key": "ami-d44b4286" }, "ap-southeast-2": { "Key": "ami-db7b39e1" }, "eu-central-1": { "Key": "ami-a6b0b7bb" }, "eu-west-1": { "Key": "ami-e4d18e93" }, "sa-east-1": { "Key": "ami-55098148" }, "us-east-1": { "Key": "ami-0d4cfd66" }, "us-west-1": { "Key": "ami-87ea13c3" }, "us-west-2": { "Key": "ami-d5c5d1e5" } } } }.

Allow internet traffic to the ELB.

RegionToAmazonLinuxAMI is a mapping of AWS region to the latest released version the Amazon Linux AMI (currently 2015.09.1).

UserData is the initial launch script run by an EC2 instance http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AmazonLinuxAMIBasics.html.