Some quick blogs on using CloudFormation to provision AWS infrastructure using code. I have attempted to put descriptive comments in line to explain what each sub-unit of code is doing.
This YAML code creates a VPC, an internet gateway, and attaches the gateway to the VPC.
Some definitions:
VPC
Amazon Virtual Private Cloud (Amazon VPC) enables you to launch AWS resources into a virtual network that you’ve defined. This virtual network closely resembles a traditional network that you’d operate in your own data center, with the benefits of using the scalable infrastructure of AWS.
Internet Gateway
An internet gateway is a horizontally scaled, redundant, and highly available VPC component that allows communication between your VPC and the internet.
VPC Gateway Attachment
Attaches an internet gateway, or a virtual private gateway to a VPC, enabling connectivity between the internet and the VPC.
The code is below:
AWSTemplateFormatVersion: '2010-09-09'
#
## The Description section (optional) enables you to include comments about your template.
#
Description:
Create VPC, an internet gateway, and attach the internet gateway to the VPC
#
## Parameters section to customize your templates
#
Parameters:
VPCName:
Description: Name of the VPC
Type: String
Default: "MyVPC"
MinLength: '1'
MaxLength: '30'
AllowedPattern: '^[a-zA-Z]+[0-9a-zA-Z\-]*$'
ConstraintDescription: Must contain alphabets and/or numbers.
VpcCIDR:
Description: Please enter the IP range (CIDR notation) for this VPC
Type: String
Default: 10.0.0.0/16
MinLength: '10'
MaxLength: '18'
AllowedPattern: "(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})/(\\d{1,2})"
ConstraintDescription: Must be a valid CIDR range of the form x.x.x.x/x.
#
## Resources created by the stack
#
Resources:
#
## Create the VPC
##
## Uses the intrinsic function Ref to get the value of the VPC Name
## from parameters above
#
VPC:
Type: AWS::EC2::VPC
Properties:
CidrBlock: !Ref VpcCIDR
EnableDnsSupport: true
EnableDnsHostnames: true
Tags:
- Key: Name
Value: !Ref VPCName
#
## Create the IGW
#
InternetGateway:
Type: AWS::EC2::InternetGateway
Properties:
Tags:
- Key: Name
Value: !Ref VPCName
#
## Connect the IGW to the VPC
#
InternetGatewayAttachment:
Type: AWS::EC2::VPCGatewayAttachment
Properties:
InternetGatewayId: !Ref InternetGateway
VpcId: !Ref VPC
#
## Resources created by the stack
##
## Uses the intrinsic function Sub to get the stack name
## from parameters above and substitute it into the name of
## the internet gateway
#
Outputs:
VPC:
Description: Name of the VPC
Value: !Ref VPC
Export:
Name: !Sub '${AWS::StackName}'
InternetGateway:
Description: Internet Gateway
Value: !Ref InternetGateway
Export:
Name: !Sub '${AWS::StackName}-InternetGateway'
