DNS settings for cloud.gov

The 18F/cg-provision repository contains the cloud.gov.tf Terraform configuration which automatically updates AWS. The configuration file leverages resources of type aws_route53_record. To learn more about Terraform configuration continue on below, or read the documentation on Terraform’s documentation site.

Examples of records

The cloud.gov.tf Terraform configuration file supports the following record types:

• A
• AAAA
• CNAME
• MX
• TXT

For more information about about the available records, please read the Amazon Route 53 documentation site.

A/AAAA (alias record) example

Alias records work like a CNAME record in that you can map one DNS name (example.com) to another target DNS name (elb1234.elb.amazonaws.com). They differ from a CNAME record in that they are not visible to resolvers. Resolvers only see the A record and the resulting IP address of the target record.

resource "aws_route53_record" "cloud_gov_<DOMAIN_NAME_UNDERSCORED>_a" {
  zone_id = "${aws_route53_zone.cloud_gov_zone.zone_id}"
  name = "<DOMAIN_NAME>."
  type = "A"
  alias {
    name = "<CANONICAL_DOMAIN_NAME>"
    zone_id = "<ZONE_ID>"
    evaluate_target_health = false
  }
}

CNAME (canonical name record) example

resource "aws_route53_record" "cloud_gov_<DOMAIN_NAME_ALIAS_UNDERSCORED>_cname" {
  zone_id = "${aws_route53_zone.cloud_gov_zone.zone_id}"
  name = "<DOMAIN_NAME_ALIAS>."
  type = "CNAME"
  ttl = 60
  records = ["<CANONICAL_DOMAIN_NAME>."]
}

MX (mail exchanger record) example

resource "aws_route53_record" "cloud_gov_<DOMAIN_NAME_UNDERSCORED>_mx" {
  zone_id = "${aws_route53_zone.cloud_gov_zone.zone_id}"
  name = "<DOMAIN_NAME>."
  type = "MX"
  ttl = 300
  records = ["<PRIORITY> <MAIL_HOST_1>", "<PRIORITY> <MAIL_HOST_2>"]
}

TXT (text record) example

resource "aws_route53_record" "cloud_gov_<DOMAIN_NAME_UNDERSCORED>_txt" {
  zone_id = "${aws_route53_zone.cloud_gov_zone.zone_id}"
  name = "<DOMAIN_NAME>."
  type = "TXT"
  ttl = 300
  records = ["<key=VALUE>"]
}

A note about Terraform syntax

The configuration files uses the Terraform syntax. To read more about Terraform syntax, please read the documentation on Terraform’s documentation site.

Submit a Pull Request

To update a DNS record, submit a pull request to the 18F/cg-provision repository with your changes. Either branches or forks are okay.

Pull requests will be reviewed and merged by a member of the infrastructure team or members of the cloud.gov team.