LAB13_GCP_DNS: Cloud DNS Managed Zones and Record Sets

DNS: Cloud DNS Managed Zones and Record Sets

☁ GCP 🟢 Beginner Cloud DNS Hosted Zone DNS Record

Scenario

Your project owns the domain example.com and you want Google Cloud DNS to act as the authoritative name server. You need to create a public Managed Zone and add an A Record that maps the root domain to the public IP address of an existing Load Balancer or VM.

Your Objectives
  • Create a google_dns_managed_zone with the dns_name example.com. (Note the trailing dot).
  • Create a google_dns_record_set of type `A` for the managed zone.
  • Set the record's TTL to 300 (5 minutes) and map it to a dummy IP (e.g. 34.120.45.67).
  • Output the Managed Zone name servers assigned by Google.

Additional Context

Record Sets: Ensure that the `name` attribute of a DNS record set exactly matches (or is a subdomain of) the `dns_name` of the zone, and that it ends with a dot indicating the DNS root. For example, `name = "example.com."`.

Private vs Public Zones: Cloud DNS can also host internal Split-Horizon DNS inside a VPC without exposing the resolution to the public internet by adding a `private_visibility_config` block and attaching networks to the zone.

variables.tf

variable "project_id"   { type = string }
variable "domain_name"  { type = string; default = "example.com." }
variable "web_ip"       { type = string; default = "34.120.45.67" }

main.tf

provider "google" {
  project = var.project_id
}

# The Public Managed Zone
resource "google_dns_managed_zone" "my_zone" {
  name        = "example-com-zone"
  dns_name    = var.domain_name
  description = "Public zone for example.com"
  
  # Ensure visibility is public (default)
  visibility  = "public"
}

# The DNS Record Set
resource "google_dns_record_set" "root_a_record" {
  # Name must match the zone's dns_name for the root record
  name         = google_dns_managed_zone.my_zone.dns_name
  managed_zone = google_dns_managed_zone.my_zone.name
  type         = "A"
  ttl          = 300

  rrdatas = [
    var.web_ip
  ]
}

outputs.tf

output "name_servers" {
  value       = google_dns_managed_zone.my_zone.name_servers
  description = "Provide these to your Domain Registrar to delegate DNS to Google"
}

Workflow Commands

terraform init
terraform apply -var="project_id=my-gcp-project-123"

# View the zone delegation name servers via gcloud
gcloud dns managed-zones describe example-com-zone

# View the records in the zone
gcloud dns record-sets list --zone=example-com-zone

terraform destroy -var="project_id=my-gcp-project-123"
✓ Expected Output After Apply
Apply complete! Resources: 2 added, 0 changed, 0 destroyed.

Outputs:

name_servers = tolist([
  "ns-cloud-a1.googledomains.com.",
  "ns-cloud-a2.googledomains.com.",
  "ns-cloud-a3.googledomains.com.",
  "ns-cloud-a4.googledomains.com.",
])

Related Posts