CloudFormation Exercise Template

This CloudFormation template is designed for educational exercises and demonstrations related to AWS CloudFormation. It provisions an Amazon EC2 instance with custom user data and associated resources.

Parameters

• NameofService: A parameter for specifying the name of the service. This is a string parameter and is used as a tag for the EC2 instance.

• InstanceTypeParameter: A parameter for specifying the EC2 instance type. It has default values and allowed values to choose from.

• KeyName: A parameter for specifying the name of an existing EC2 key pair. This key pair is used for SSH access to the EC2 instance.

Mappings

• AmiRegionMap: This mapping defines AMIs (Amazon Machine Images) for different AWS regions. It is used to select the appropriate AMI based on the region.

Resources

• WebServer: This is the main resource and represents the EC2 instance. Here's what it does:

  • It uses the AWS::CloudFormation::Init metadata section to define configurations for the EC2 instance. These configurations include packages to install, commands to run, files to create, and services to enable.
  • The UserData section contains a shell script that is executed when the instance launches. It installs the AWS CloudFormation tools, runs cfn-init and cfn-signal, which are used for CloudFormation resource initialization and signaling stack creation completion.
  • The InstanceType, KeyName, and ImageId properties are set based on the specified parameters and mapping.
  • It sets a tag on the instance with the name of the service specified in the NameofService parameter.
  • It associates the instance with the VprofileSG security group.

• VprofileSG: This is an EC2 security group resource that allows inbound traffic on ports 80 (HTTP) and 22 (SSH) from specific IP addresses.

Outputs

• PrintSomeInfo: An output that displays the public DNS name of the EC2 instance.

Purpose

The purpose of this CloudFormation template is to demonstrate the following concepts:

• Parameter usage: How to define parameters for customizing resource creation.

• Mapping usage: How to define mappings for region-specific resources.

• Resource creation: How to create AWS resources like EC2 instances and security groups.

• Metadata and User Data: How to use metadata and user data to customize EC2 instances during launch.

• Output usage: How to create outputs to retrieve information from the created stack.

This template can be used for educational purposes and as a starting point for more complex CloudFormation stacks.