Network Cloudformation Template

The below CFT is a working example of creating a VPC. Please take a look at how AZs have been represented here in the following format - AvailabilityZone: !Select [ 0, !GetAZs '' ]

Description: This template deploys a VPC, with a pair of public and private subnets spread across two Availability Zones. It deploys an internet gateway, with a default route on the public subnets. It deploys a pair of NAT gateways (one in each AZ), and default routes for them in the private subnets.

Parameters: EnvironmentName: Description: An environment name that is prefixed to resource names Type: String

VpcCIDR: Description: Please enter the IP range (CIDR notation) for this VPC Type: String Default: 10.192.0.0/16

PublicSubnet1CIDR: Description: Please enter the IP range (CIDR notation) for the public subnet in the first Availability Zone Type: String Default: 10.192.10.0/24

PublicSubnet2CIDR: Description: Please enter the IP range (CIDR notation) for the public subnet in the second Availability Zone Type: String Default: 10.192.11.0/24

PrivateSubnet1CIDR: Description: Please enter the IP range (CIDR notation) for the private subnet in the first Availability Zone Type: String Default: 10.192.20.0/24

PrivateSubnet2CIDR: Description: Please enter the IP range (CIDR notation) for the private subnet in the second Availability Zone Type: String Default: 10.192.21.0/24

Resources: VPC: Type: AWS::EC2::VPC Properties: CidrBlock: !Ref VpcCIDR EnableDnsSupport: true EnableDnsHostnames: true Tags: - Key: Name Value: !Ref EnvironmentName

InternetGateway: Type: AWS::EC2::InternetGateway Properties: Tags: - Key: Name Value: !Ref EnvironmentName

InternetGatewayAttachment: Type: AWS::EC2::VPCGatewayAttachment Properties: InternetGatewayId: !Ref InternetGateway VpcId: !Ref VPC

PublicSubnet1: Type: AWS::EC2::Subnet Properties: VpcId: !Ref VPC AvailabilityZone: !Select [ 0, !GetAZs '' ] CidrBlock: !Ref PublicSubnet1CIDR MapPublicIpOnLaunch: true Tags: - Key: Name Value: !Sub ${EnvironmentName} Public Subnet (AZ1)

PublicSubnet2: Type: AWS::EC2::Subnet Properties: VpcId: !Ref VPC AvailabilityZone: !Select [ 1, !GetAZs '' ] CidrBlock: !Ref PublicSubnet2CIDR MapPublicIpOnLaunch: true Tags: - Key: Name Value: !Sub ${EnvironmentName} Public Subnet (AZ2)

PrivateSubnet1: Type: AWS::EC2::Subnet Properties: VpcId: !Ref VPC AvailabilityZone: !Select [ 0, !GetAZs '' ] CidrBlock: !Ref PrivateSubnet1CIDR MapPublicIpOnLaunch: false Tags: - Key: Name Value: !Sub ${EnvironmentName} Private Subnet (AZ1)

PrivateSubnet2: Type: AWS::EC2::Subnet Properties: VpcId: !Ref VPC AvailabilityZone: !Select [ 1, !GetAZs '' ] CidrBlock: !Ref PrivateSubnet2CIDR MapPublicIpOnLaunch: false Tags: - Key: Name Value: !Sub ${EnvironmentName} Private Subnet (AZ2)

NatGateway1EIP: Type: AWS::EC2::EIP DependsOn: InternetGatewayAttachment Properties: Domain: vpc

NatGateway2EIP: Type: AWS::EC2::EIP DependsOn: InternetGatewayAttachment Properties: Domain: vpc

NatGateway1: Type: AWS::EC2::NatGateway Properties: AllocationId: !GetAtt NatGateway1EIP.AllocationId SubnetId: !Ref PublicSubnet1

NatGateway2: Type: AWS::EC2::NatGateway Properties: AllocationId: !GetAtt NatGateway2EIP.AllocationId SubnetId: !Ref PublicSubnet2

PublicRouteTable: Type: AWS::EC2::RouteTable Properties: VpcId: !Ref VPC Tags: - Key: Name Value: !Sub ${EnvironmentName} Public Routes

DefaultPublicRoute: Type: AWS::EC2::Route DependsOn: InternetGatewayAttachment Properties: RouteTableId: !Ref PublicRouteTable DestinationCidrBlock: 0.0.0.0/0 GatewayId: !Ref InternetGateway

PublicSubnet1RouteTableAssociation: Type: AWS::EC2::SubnetRouteTableAssociation Properties: RouteTableId: !Ref PublicRouteTable SubnetId: !Ref PublicSubnet1

PublicSubnet2RouteTableAssociation: Type: AWS::EC2::SubnetRouteTableAssociation Properties: RouteTableId: !Ref PublicRouteTable SubnetId: !Ref PublicSubnet2

PrivateRouteTable1: Type: AWS::EC2::RouteTable Properties: VpcId: !Ref VPC Tags: - Key: Name Value: !Sub ${EnvironmentName} Private Routes (AZ1)

DefaultPrivateRoute1: Type: AWS::EC2::Route Properties: RouteTableId: !Ref PrivateRouteTable1 DestinationCidrBlock: 0.0.0.0/0 NatGatewayId: !Ref NatGateway1

PrivateSubnet1RouteTableAssociation: Type: AWS::EC2::SubnetRouteTableAssociation Properties: RouteTableId: !Ref PrivateRouteTable1 SubnetId: !Ref PrivateSubnet1

PrivateRouteTable2: Type: AWS::EC2::RouteTable Properties: VpcId: !Ref VPC Tags: - Key: Name Value: !Sub ${EnvironmentName} Private Routes (AZ2)

DefaultPrivateRoute2: Type: AWS::EC2::Route Properties: RouteTableId: !Ref PrivateRouteTable2 DestinationCidrBlock: 0.0.0.0/0 NatGatewayId: !Ref NatGateway2

PrivateSubnet2RouteTableAssociation: Type: AWS::EC2::SubnetRouteTableAssociation Properties: RouteTableId: !Ref PrivateRouteTable2 SubnetId: !Ref PrivateSubnet2

NoIngressSecurityGroup: Type: AWS::EC2::SecurityGroup Properties: GroupName: "no-ingress-sg" GroupDescription: "Security group with no ingress rule" VpcId: !Ref VPC

Outputs: VPC: Description: A reference to the created VPC Value: !Ref VPC

PublicSubnets: Description: A list of the public subnets Value: !Join [ ",", [ !Ref PublicSubnet1, !Ref PublicSubnet2 ]]

PrivateSubnets: Description: A list of the private subnets Value: !Join [ ",", [ !Ref PrivateSubnet1, !Ref PrivateSubnet2 ]]

PublicSubnet1: Description: A reference to the public subnet in the 1st Availability Zone Value: !Ref PublicSubnet1

PublicSubnet2: Description: A reference to the public subnet in the 2nd Availability Zone Value: !Ref PublicSubnet2

PrivateSubnet1: Description: A reference to the private subnet in the 1st Availability Zone Value: !Ref PrivateSubnet1

PrivateSubnet2: Description: A reference to the private subnet in the 2nd Availability Zone Value: !Ref PrivateSubnet2

NoIngressSecurityGroup: Description: Security group with no ingress rule Value: !Ref NoIngressSecurityGroup