but3-iac/terraform/modules/compute/main.tf

resource "google_compute_instance" "frontend"{
  name = "ma-frontend"
  machine_type = var.instance_type
  zone = var.zone
  
  boot_disk{
    initialize_params {
      image = "debian-11"
      size = 10
    }
  }

  network_interface {
    access_config {}
    subnetwork = google_compute_subnetwork.frontend.id
  }

  tags = ["frontend", "ssh"]
  
  metadata = {
    enable-oslogin = "TRUE"
  } 
}

resource "google_compute_instance" "backend"{
  name = "ma-backend"
  machine_type = var.instance_type
  zone = var.zone
  
  boot_disk{
    initialize_params {
      image = "debian-11"
      size = 10
    }
  }

  network_interface {
    subnetwork = google_compute_subnetwork.backend.id
  }

  tags = ["backend", "ssh"]
  
  metadata = {
    enable-oslogin = "TRUE"
  } 
}

resource "google_compute_instance" "database"{
  name = "ma-database"
  machine_type = var.instance_type
  zone = var.zone
  
  boot_disk{
    initialize_params {
      image = "debian-11"
      size = 20
    }
  }

  network_interface {
    subnetwork = google_compute_subnetwork.database.id
  }

  tags = ["database", "ssh"]
  
  metadata = {
    enable-oslogin = "TRUE"
  } 
}