Core Infrastructure for ECS

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We will use a Cloudformation template to build up the infrastructure. In the infrastructure, we will have a VPC, Subnets on different AZ, Internet Gateway, Route Table. Lets create a Cloudformation template named core-infrastructure-setup.yml which should look like,

AWSTemplateFormatVersion: '2010-09-09'
Description: VPC and subnets as base for an ECS cluster
Parameters:
  EnvironmentName:
    Type: String
    Default: ecs-course

Mappings:
  SubnetConfig:
    VPC:
      CIDR: '172.16.0.0/16'
    PublicOne:
      CIDR: '172.16.0.0/24'
    PublicTwo:
      CIDR: '172.16.1.0/24'

Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      EnableDnsSupport: true
      EnableDnsHostnames: true
      CidrBlock: !FindInMap ['SubnetConfig', 'VPC', 'CIDR']

  PublicSubnetOne:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone:
        Fn::Select:
          - 0
          - Fn::GetAZs: { Ref: 'AWS::Region' }
      VpcId: !Ref 'VPC'
      CidrBlock: !FindInMap ['SubnetConfig', 'PublicOne', 'CIDR']
      MapPublicIpOnLaunch: true
  PublicSubnetTwo:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone:
        Fn::Select:
          - 1
          - Fn::GetAZs: { Ref: 'AWS::Region' }
      VpcId: !Ref 'VPC'
      CidrBlock: !FindInMap ['SubnetConfig', 'PublicTwo', 'CIDR']
      MapPublicIpOnLaunch: true

  InternetGateway:
    Type: AWS::EC2::InternetGateway
  GatewayAttachement:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref 'VPC'
      InternetGatewayId: !Ref 'InternetGateway'
  PublicRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref 'VPC'
  PublicRoute:
    Type: AWS::EC2::Route
    DependsOn: GatewayAttachement
    Properties:
      RouteTableId: !Ref 'PublicRouteTable'
      DestinationCidrBlock: '0.0.0.0/0'
      GatewayId: !Ref 'InternetGateway'
  PublicSubnetOneRouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnetOne
      RouteTableId: !Ref PublicRouteTable
  PublicSubnetTwoRouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnetTwo
      RouteTableId: !Ref PublicRouteTable

Outputs:
  VpcId:
    Description: The ID of the VPC that this stack is deployed in
    Value: !Ref 'VPC'
    Export:
      Name: !Sub ${EnvironmentName}:VpcId
  PublicSubnetOne:
    Description: Public subnet one
    Value: !Ref 'PublicSubnetOne'
    Export:
      Name: !Sub ${EnvironmentName}:PublicSubnetOne
  PublicSubnetTwo:
    Description: Public subnet two
    Value: !Ref 'PublicSubnetTwo'
    Export:
      Name: !Sub ${EnvironmentName}:PublicSubnetTwo

Make sure the aws-cli is installed in your machine. Now create the stack from the Cloudformation template by,

aws cloudformation create-stack --capabilities CAPABILITY_IAM --stack-name ecs-core-infrastructure --template-body file://./core-infrastructure-setup.yml