Google Cloud Private DNS

Private Cloud DNS in Google Cloud Platform (GCP) enables the management of DNS zones and records for private network resources. It facilitates the organization and accessibility of internal assets within a secure network environment, without exposing them to the public internet. This functionality ensures streamlined communication among virtual machine instances, Kubernetes clusters, and other resources using domain names within the confines of the private network.

Requirements:

Google Cloud Platform:

folder ID
billing ID
Service Account Key

Local machine:

gcloud CLI
git CLI
terraform CLI

Clone this repo

git clone https://github.com/froggologies/gcp-terraform-exp-cloud-dns.git && cd gcp-terraform-exp-cloud-dns

Set environment variables:

export GOOGLE_APPLICATION_CREDENTIALS=<PATH_TO_SERVICE_ACCOUNT_KEY>
export TF_VAR_billing_account=<BILLING_ACCOUNT_ID>
export TF_VAR_folder_id=<FOLDER_ID>

Provision resources

Main resources that are created for this project are:

instance-1: GCE instance for nginx server
instance-2: GCE instance for testing the private dns
private-zone (private.example.com): Private Cloud DNS

Change the backend in terraform/backend.tf to your backend configuration or delete it if you want to use local backend.

Initialize Terraform:

terraform -chdir=terraform init

Apply Terraform:

terraform -chdir=terraform apply -auto-approve

Testing

SSH to the instance-2:

gcloud compute ssh <INSTANCE_2_NAME> --project <PROJECT_ID> --zone us-central1-a --tunnel-through-iap

Curl nginx server through private DNS:

curl private.example.com

You should see:

<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
.
.
.
<p><em>Thank you for using nginx.</em></p>
</body>
</html>

That means the private DNS is working properly.

Cleanup

Destroy terraform resources:

terraform -chdir=terraform destroy -auto-approve