title: Terraform : Tagging ALL google compute INSTANCES at once using Terraform
body: <p>I have an existing project with instances running in the project. I have authenticated in the project using Terraform and credentials file. I am suppose to get existing resource by inputing the project ID.  </p>
  
  <pre><code>provider "google" {
    credentials = "${file("${var.path}/terraform-ma.json")}"
  
    project = "terraform-ma-2020"
    region  = "us-central1"
    zone    = "us-central1-b"
  }
  
  
  
  data "google_project" "project" {
  }
  
  output "project_id" {
    value = data.google_project.project.project_id
  
  }
  </code></pre>