Auth

I gereated a .json file with my private key and other auth items from google cloud ui. You should just be able to follow the instructions https://developers.google.com/workspace/guides/create-credentials#create_credentials_for_a_service_account

I have set-up the terraform files to accept a SOPS encrypted creds.json file. Just make sure you set the credentials_file_en variable. If you dont want to go through all that and just want to use the json key you downloaded use the credentials_file variable and leave the 'en' variable empty.

Tfvars

If you are not familiar with this. You will have to create a var.tfvars file that will read your variable information. Like the directory of auth file. This file also contains potential sensitive info.

It should look similar to

workcidr = "1.2.3.4/32"
project_id = "your_gcloud_project_id"
credentials = "creds.json"

Initialize Terraform modules

terraform init

Run a plan

terraform plan -var-files=vars.tfvars

Apply Terraform with tfvars file

terraform apply -var-file=vars.tfvars

To clean-up

terraform destroy