Configure Amazon VPC resources with AWS CloudFormation - AWS CloudFormation
Enable IPv6 egress-only internet access in a VPCElastic network interface (ENI) template snippets

Configure Amazon VPC resources with AWS CloudFormation

This section provides examples for configuring Amazon VPC resources using AWS CloudFormation. VPCs allow you to create a virtual network within AWS, and these snippets show how to configure aspects of VPCs to meet your networking requirements.

Enable IPv6 egress-only internet access in a VPC

An egress-only internet gateway allows instances within a VPC to access the internet and prevent resources on the internet from communicating with the instances. The following snippet enables IPv6 egress-only internet access from within a VPC. It creates a VPC with an IPv4 address range of 10.0.0/16 using an AWS::EC2::VPC resource. A route table is associated with this VPC resource using an AWS::EC2::RouteTable resource. The route table manages routes for instances within the VPC. An AWS::EC2::EgressOnlyInternetGateway is used to create an egress-only internet gateway to enable IPv6 communication for outbound traffic from instances within the VPC, while preventing inbound traffic. An AWS::EC2::Route resource is specified to create an IPv6 route in the route table that directs all outbound IPv6 traffic (::/0) to the egress-only internet gateway.

For more information about egress-only internet gateways, see Enable outbound IPv6 traffic using an egress-only internet gateway.

JSON

"DefaultIpv6Route": {
    "Type": "AWS::EC2::Route",
    "Properties": {
        "DestinationIpv6CidrBlock": "::/0",
        "EgressOnlyInternetGatewayId": {
            "Ref": "EgressOnlyInternetGateway"
        },
        "RouteTableId": {
            "Ref": "RouteTable"
        }
    }
},
"EgressOnlyInternetGateway": {
    "Type": "AWS::EC2::EgressOnlyInternetGateway",
    "Properties": {
        "VpcId": {
            "Ref": "VPC"
        }
    }
},
"RouteTable": {
    "Type": "AWS::EC2::RouteTable",
    "Properties": {
        "VpcId": {
            "Ref": "VPC"
        }
    }
},
"VPC": {
    "Type": "AWS::EC2::VPC",
    "Properties": {
        "CidrBlock": "10.0.0.0/16"
    }
}

YAML

DefaultIpv6Route:
  Type: "AWS::EC2::Route"
  Properties:
    DestinationIpv6CidrBlock: "::/0"
    EgressOnlyInternetGatewayId:
      Ref: "EgressOnlyInternetGateway"
    RouteTableId:
      Ref: "RouteTable"
EgressOnlyInternetGateway:
  Type: "AWS::EC2::EgressOnlyInternetGateway"
  Properties:
    VpcId:
      Ref: "VPC"
RouteTable:
  Type: "AWS::EC2::RouteTable"
  Properties:
    VpcId:
      Ref: "VPC"
VPC:
  Type: "AWS::EC2::VPC"
  Properties:
    CidrBlock: "10.0.0.0/16"

Elastic network interface (ENI) template snippets

Create an Amazon EC2 instance with attached elastic network interfaces (ENIs)

The following example snippet creates an Amazon EC2 instance using an AWS::EC2::Instance resource in the specified Amazon VPC and subnet. It attaches two network interfaces (ENIs) with the instance, associates Elastic IP addresses to the instances through the attached ENIs, and configures the security group for SSH and HTTP access. User data is supplied to the instance as part of the launch configuration when the instance is created. The user data includes a script encoded in base64 format to ensure it is passed to the instance. When the instance is launched, the script runs automatically as part of the bootstrapping process. It installs ec2-net-utils, configures the network interfaces, and starts the HTTP service.

To determine the appropriate Amazon Machine Image (AMI) based on the selected Region, the snippet uses a Fn::FindInMap function that looks up values in a RegionMap mapping. This mapping must be defined in the larger template. The two network interfaces are created using AWS::EC2::NetworkInterface resources. Elastic IP addresses are specified using AWS::EC2::EIP resources allocated to the vpc domain. These elastic IP addresses are associated with the network interfaces using AWS::EC2::EIPAssociation resources.

The Outputs section defines values or resources that you want to access after the stack is created. In this snippet, the defined output is InstancePublicIp, which represents the public IP address of the EC2 instance created by the stack. You can retrieve this output in the Output tab on the AWS CloudFormation console, or using the aws cloudformation describe-stackscommand.

For more information about elastic network interfaces, see Elastic network interfaces.

JSON

"Resources": {
    "ControlPortAddress": {
        "Type": "AWS::EC2::EIP",
        "Properties": {
            "Domain": "vpc"
        }
    },
    "AssociateControlPort": {
        "Type": "AWS::EC2::EIPAssociation",
        "Properties": {
            "AllocationId": {
                "Fn::GetAtt": [
                    "ControlPortAddress",
                    "AllocationId"
                ]
            },
            "NetworkInterfaceId": {
                "Ref": "controlXface"
            }
        }
    },
    "WebPortAddress": {
        "Type": "AWS::EC2::EIP",
        "Properties": {
            "Domain": "vpc"
        }
    },
    "AssociateWebPort": {
        "Type": "AWS::EC2::EIPAssociation",
        "Properties": {
            "AllocationId": {
                "Fn::GetAtt": [
                    "WebPortAddress",
                    "AllocationId"
                ]
            },
            "NetworkInterfaceId": {
                "Ref": "webXface"
            }
        }
    },
    "SSHSecurityGroup": {
        "Type": "AWS::EC2::SecurityGroup",
        "Properties": {
            "VpcId": {
                "Ref": "VpcId"
            },
            "GroupDescription": "Enable SSH access via port 22",
            "SecurityGroupIngress": [
                {
                    "CidrIp": "0.0.0.0/0",
                    "FromPort": 22,
                    "IpProtocol": "tcp",
                    "ToPort": 22
                }
            ]
        }
    },
    "WebSecurityGroup": {
        "Type": "AWS::EC2::SecurityGroup",
        "Properties": {
            "VpcId": {
                "Ref": "VpcId"
            },
            "GroupDescription": "Enable HTTP access via user-defined port",
            "SecurityGroupIngress": [
                {
                    "CidrIp": "0.0.0.0/0",
                    "FromPort": 80,
                    "IpProtocol": "tcp",
                    "ToPort": 80
                }
            ]
        }
    },
    "controlXface": {
        "Type": "AWS::EC2::NetworkInterface",
        "Properties": {
            "SubnetId": {
                "Ref": "SubnetId"
            },
            "Description": "Interface for controlling traffic such as SSH",
            "GroupSet": [
                {
                    "Fn::GetAtt": [
                        "SSHSecurityGroup",
                        "GroupId"
                    ]
                }
            ],
            "SourceDestCheck": true,
            "Tags": [
                {
                    "Key": "Network",
                    "Value": "Control"
                }
            ]
        }
    },
    "webXface": {
        "Type": "AWS::EC2::NetworkInterface",
        "Properties": {
            "SubnetId": {
                "Ref": "SubnetId"
            },
            "Description": "Interface for web traffic",
            "GroupSet": [
                {
                    "Fn::GetAtt": [
                        "WebSecurityGroup",
                        "GroupId"
                    ]
                }
            ],
            "SourceDestCheck": true,
            "Tags": [
                {
                    "Key": "Network",
                    "Value": "Web"
                }
            ]
        }
    },
    "Ec2Instance": {
        "Type": "AWS::EC2::Instance",
        "Properties": {
            "ImageId": {
                "Fn::FindInMap": [
                    "RegionMap",
                    {
                        "Ref": "AWS::Region"
                    },
                    "AMI"
                ]
            },
            "KeyName": {
                "Ref": "KeyName"
            },
            "NetworkInterfaces": [
                {
                    "NetworkInterfaceId": {
                        "Ref": "controlXface"
                    },
                    "DeviceIndex": "0"
                },
                {
                    "NetworkInterfaceId": {
                        "Ref": "webXface"
                    },
                    "DeviceIndex": "1"
                }
            ],
            "Tags": [
                {
                    "Key": "Role",
                    "Value": "Test Instance"
                }
            ],
            "UserData": {
                "Fn::Base64": {
                    "Fn::Sub": "#!/bin/bash -xe\nyum install ec2-net-utils -y\nec2ifup eth1\nservice httpd start\n"
                }
            }
        }
    }
},
"Outputs": {
    "InstancePublicIp": {
        "Description": "Public IP Address of the EC2 Instance",
        "Value": {
            "Fn::GetAtt": [
                "Ec2Instance",
                "PublicIp"
            ]
        }
    }
}

YAML

Resources:
  ControlPortAddress:
    Type: 'AWS::EC2::EIP'
    Properties:
      Domain: vpc
  AssociateControlPort:
    Type: 'AWS::EC2::EIPAssociation'
    Properties:
      AllocationId:
        Fn::GetAtt:
          - ControlPortAddress
          - AllocationId
      NetworkInterfaceId:
        Ref: controlXface
  WebPortAddress:
    Type: 'AWS::EC2::EIP'
    Properties:
      Domain: vpc
  AssociateWebPort:
    Type: 'AWS::EC2::EIPAssociation'
    Properties:
      AllocationId:
        Fn::GetAtt:
          - WebPortAddress
          - AllocationId
      NetworkInterfaceId:
        Ref: webXface
  SSHSecurityGroup:
    Type: 'AWS::EC2::SecurityGroup'
    Properties:
      VpcId:
        Ref: VpcId
      GroupDescription: Enable SSH access via port 22
      SecurityGroupIngress:
        - CidrIp: 0.0.0.0/0
          FromPort: 22
          IpProtocol: tcp
          ToPort: 22
  WebSecurityGroup:
    Type: 'AWS::EC2::SecurityGroup'
    Properties:
      VpcId:
        Ref: VpcId
      GroupDescription: Enable HTTP access via user-defined port
      SecurityGroupIngress:
        - CidrIp: 0.0.0.0/0
          FromPort: 80
          IpProtocol: tcp
          ToPort: 80
  controlXface:
    Type: 'AWS::EC2::NetworkInterface'
    Properties:
      SubnetId:
        Ref: SubnetId
      Description: Interface for controlling traffic such as SSH
      GroupSet:
        - Fn::GetAtt:
            - SSHSecurityGroup
            - GroupId
      SourceDestCheck: true
      Tags:
        - Key: Network
          Value: Control
  webXface:
    Type: 'AWS::EC2::NetworkInterface'
    Properties:
      SubnetId:
        Ref: SubnetId
      Description: Interface for web traffic
      GroupSet:
        - Fn::GetAtt:
            - WebSecurityGroup
            - GroupId
      SourceDestCheck: true
      Tags:
        - Key: Network
          Value: Web
  Ec2Instance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId:
        Fn::FindInMap:
          - RegionMap
          - Ref: AWS::Region
          - AMI
      KeyName:
        Ref: KeyName
      NetworkInterfaces:
        - NetworkInterfaceId:
            Ref: controlXface
          DeviceIndex: "0"
        - NetworkInterfaceId:
            Ref: webXface
          DeviceIndex: "1"
      Tags:
        - Key: Role
          Value: Test Instance
      UserData:
        Fn::Base64: !Sub |
          #!/bin/bash -xe
          yum install ec2-net-utils -y
          ec2ifup eth1
          service httpd start
Outputs:
  InstancePublicIp:
    Description: Public IP Address of the EC2 Instance
    Value:
      Fn::GetAtt:
        - Ec2Instance
        - PublicIp