AWS Amazon EC2 VPC DHCP Options
This page shows how to write Terraform and CloudFormation for Amazon EC2 VPC DHCP Options and write them securely.
aws_default_vpc_dhcp_options (Terraform)
The VPC DHCP Options in Amazon EC2 can be configured in Terraform with the resource name aws_default_vpc_dhcp_options. The following sections describe 5 examples of how to use the resource and its parameters.
Example Usage from GitHub
resource "aws_default_vpc_dhcp_options" "default" {
tags = {
Name = "default"
}
}
resource "aws_default_vpc_dhcp_options" "default_dhcp_options_VPC1" {
tags = {
Name = "Default DHCP Option Set"
}
}
resource "aws_default_vpc_dhcp_options" "default_vpc_dhcp_options" {
count = var.enable_default_vpc ? 1 : 0
netbios_name_servers = var.default_vpc_dhcp_options_netbios_name_servers
netbios_node_type = var.default_vpc_dhcp_options_netbios_node_type
resource "aws_default_vpc_dhcp_options" "default" {
tags = {
Name = "Default DHCP Option Set"
}
}
resource "aws_default_vpc_dhcp_options" "this" {
netbios_name_servers = var.netbios_name_servers
netbios_node_type = var.netbios_node_type
tags = var.tags
}
Parameters
-
arnoptional computed - string -
domain_nameoptional computed - string -
domain_name_serversoptional computed - string -
idoptional computed - string -
netbios_name_serversoptional - list of string -
netbios_node_typeoptional - string -
ntp_serversoptional computed - string -
owner_idoptional computed - string -
tagsoptional - map from string to string
Explanation in Terraform Registry
Provides a resource to manage the default AWS DHCP Options Set in the current region. Each AWS region comes with a default set of DHCP options. This is an advanced resource, and has special caveats to be aware of when using it. Please read this document in its entirety before using this resource. The
aws_default_vpc_dhcp_optionsbehaves differently from normal resources, in that Terraform does not create this resource, but instead "adopts" it into management.
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.
aws_default_vpc
Ensure to avoid using default VPC
It is better to define the own VPC and use it.
aws_network_acl_rule
Ensure your network ACL rule blocks unwanted inbound traffic
It is better to block unwanted inbound traffic.
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).
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.
aws_security_group
Ensure your security group blocks unwanted inbound traffic
It is better to block unwanted inbound traffic.
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
Type: AWS::EC2::VPCDHCPOptionsAssociation
Properties:
VpcId:
Ref: VPC
DhcpOptionsId:
Ref: DhcpOptions
Type: 'AWS::EC2::VPCDHCPOptionsAssociation'
Properties:
VpcId: !Ref vpc1
DhcpOptionsId: !Ref dopt1
Outputs:
VpcId:
Type: 'AWS::EC2::VPCDHCPOptionsAssociation'
Properties:
VpcId: !Ref vpc1
DhcpOptionsId: !Ref dopt1
subnet1:
Type: AWS::EC2::VPCDHCPOptionsAssociation
Properties:
DhcpOptionsId: !Ref DhcpOptions
VpcId: !Ref Vpc
#
Type: AWS::EC2::VPCDHCPOptionsAssociation
Properties:
DhcpOptionsId: !Ref DhcpOptions
VpcId: !Ref Vpc
#
"Type": "AWS::EC2::VPCDHCPOptionsAssociation",
"Properties": {
"DhcpOptionsId": {
"Ref": "optionSet"
},
"VpcId": {
"Type" : "AWS::EC2::VPCDHCPOptionsAssociation",
"Properties" : {
"VpcId": { "Ref" : "VPC" },
"DhcpOptionsId": { "Ref" : "DHCPOpts" }
}
}
"Type": "AWS::EC2::VPCDHCPOptionsAssociation"
}
}
"Type": "AWS::EC2::VPCDHCPOptionsAssociation",
"Properties": {
"VpcId": {"Fn::ImportValue": "VPCId"},
"DhcpOptionsId": {
"Ref": "DHCPOpt"
}
"Type": "AWS::EC2::VPCDHCPOptionsAssociation",
"Properties": {
"VpcId": {"Fn::ImportValue": "VPCId"},
"DhcpOptionsId": {
"Ref": "DHCPOpt"
}
Parameters
-
DhcpOptionsIdrequired - String -
VpcIdrequired - String
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 VPC DHCP Options?
AWS Amazon EC2 VPC DHCP Options 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 VPC DHCP Options?
For Terraform, the asbubam/2dal-infrastructure, nzebar/TerraformAWS and asrkata/SebastianUA-terraform 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-cross-stack and d-shimizu/aws-cloudformation-sample-single-stack source code examples are useful. See the CloudFormation Example section for further details.
