AWS Amazon EC2 DHCP Options Association

This page shows how to write Terraform and CloudFormation for Amazon EC2 DHCP Options Association and write them securely.

aws_vpc_dhcp_options_association (Terraform)

The DHCP Options Association in Amazon EC2 can be configured in Terraform with the resource name aws_vpc_dhcp_options_association. The following sections describe 2 examples of how to use the resource and its parameters.

Example Usage from GitHub

main.tf#L13
resource "aws_vpc_dhcp_options_association" "principal" {
  vpc_id          = var.vpc_id
  dhcp_options_id = aws_vpc_dhcp_options.principal.id
}

resource "aws_vpc_dhcp_options" "secondary" {
main.tf#L13
resource "aws_vpc_dhcp_options_association" "principal" {
  vpc_id          = var.vpc_id
  dhcp_options_id = aws_vpc_dhcp_options.principal.id
}

resource "aws_vpc_dhcp_options" "secondary" {

Review your Terraform file for AWS best practices

Shisho Cloud, our free checker to make sure your Terraform configuration follows best practices, is available (beta).

Parameters

Explanation in Terraform Registry

Provides a VPC DHCP Options Association resource.

Tips: Best Practices for The Other AWS Amazon EC2 Resources

In addition to the aws_default_vpc, AWS Amazon EC2 has the other resources that should be configured for security reasons. Please check some examples of those resources and precautions.

risk-label

aws_default_vpc

Ensure to avoid using default VPC

It is better to define the own VPC and use it.

risk-label

aws_network_acl_rule

Ensure your network ACL rule blocks unwanted inbound traffic

It is better to block unwanted inbound traffic.

risk-label

aws_ebs_volume

Ensure to use a customer-managed key for EBS volume encryption

It is better to use a customer-managed key for EBS volume encryption. It can be gain more control over the encryption by using customer-managed keys (CMK).

risk-label

aws_instance

Ensure to avoid storing AWS access keys in user data

It is better to avoid storing AWS access keys in user data. `aws_iam_instance_profile` could be used instead.

risk-label

aws_security_group

Ensure your security group blocks unwanted inbound traffic

It is better to block unwanted inbound traffic.

Review your AWS Amazon EC2 settings

In addition to the above, there are other security points you should be aware of making sure that your .tf files are protected in Shisho Cloud.

AWS::EC2::VPCDHCPOptionsAssociation (CloudFormation)

The VPCDHCPOptionsAssociation in EC2 can be configured in CloudFormation with the resource name AWS::EC2::VPCDHCPOptionsAssociation. The following sections describe 10 examples of how to use the resource and its parameters.

Example Usage from GitHub

network.yml#L94
    Type: AWS::EC2::VPCDHCPOptionsAssociation
    Properties:
      VpcId:
        Ref: VPC
      DhcpOptionsId:
        Ref: DhcpOptions
sample-cfn.yml#L74
    Type: 'AWS::EC2::VPCDHCPOptionsAssociation'
    Properties:
      VpcId: !Ref vpc1
      DhcpOptionsId: !Ref dopt1

  subnet1:
01-create-vpc-template-cfn.yml#L74
    Type: 'AWS::EC2::VPCDHCPOptionsAssociation'
    Properties:
      VpcId: !Ref vpc1
      DhcpOptionsId: !Ref dopt1
Outputs:
  VpcId:
vpc.yml#L26
    Type: AWS::EC2::VPCDHCPOptionsAssociation
    Properties:
      DhcpOptionsId: !Ref DhcpOptions
      VpcId: !Ref Vpc

  #
vpc.yml#L26
    Type: AWS::EC2::VPCDHCPOptionsAssociation
    Properties:
      DhcpOptionsId: !Ref DhcpOptions
      VpcId: !Ref Vpc

  #
setDHCPoption.json#L45
            "Type": "AWS::EC2::VPCDHCPOptionsAssociation",
            "Properties": {
                "DhcpOptionsId": {
                    "Ref": "optionSet"
                },
                "VpcId": {
private-zone-dhcp-assoc.json#L32
            "Type" : "AWS::EC2::VPCDHCPOptionsAssociation",
            "Properties" : {
                "VpcId": { "Ref" : "VPC" },
                "DhcpOptionsId": { "Ref" : "DHCPOpts" }
            }
        }
vpc08bf684639ded31d9dhcp.json#L27
            "Type": "AWS::EC2::VPCDHCPOptionsAssociation"
        }
    }
dhcp.json#L18
      "Type": "AWS::EC2::VPCDHCPOptionsAssociation",
      "Properties": {
        "VpcId": {"Fn::ImportValue": "VPCId"},
        "DhcpOptionsId": {
          "Ref": "DHCPOpt"
        }
dhcp.json#L18
      "Type": "AWS::EC2::VPCDHCPOptionsAssociation",
      "Properties": {
        "VpcId": {"Fn::ImportValue": "VPCId"},
        "DhcpOptionsId": {
          "Ref": "DHCPOpt"
        }

Parameters

Explanation in CloudFormation Registry

Associates a set of DHCP options with a VPC, or associates no DHCP options with the VPC.

After you associate the options with the VPC, any existing instances and all new instances that you launch in that VPC use the options. You don't need to restart or relaunch the instances. They automatically pick up the changes within a few hours, depending on how frequently the instance renews its DHCP lease. You can explicitly renew the lease using the operating system on the instance.

Frequently asked questions

What is AWS Amazon EC2 DHCP Options Association?

AWS Amazon EC2 DHCP Options Association is a resource for Amazon EC2 of Amazon Web Service. Settings can be wrote in Terraform and CloudFormation.

Where can I find the example code for the AWS Amazon EC2 DHCP Options Association?

For Terraform, the andremulin/aws_route53_strategies_article and andremulin/aws_route53_strategies_article source code examples are useful. See the Terraform Example section for further details.

For CloudFormation, the saineju/ansible-windows-demo, d-shimizu/aws-cloudformation-sample-single-stack and d-shimizu/aws-cloudformation-sample-cross-stack source code examples are useful. See the CloudFormation Example section for further details.