terraform-demo/main.tf

## TERRAFORM
terraform {
  required_version = ">= 0.12"
}

## PROVIDER
provider "google" {
  project     = var.gcp_project_id
  credentials = file(var.gcp_auth_file)
  region      = var.gcp_region
}

## NETWORK
resource "google_compute_network" "vpc_network" {
  name                    = "my-custom-network"
  auto_create_subnetworks = false
  mtu                     = 1460
}

resource "google_compute_subnetwork" "default" {
  name          = "my-custom-subnet"
  ip_cidr_range = "10.0.1.0/24"
  region        = var.gcp_region
  network       = google_compute_network.vpc_network.id
}

# VM
resource "google_compute_instance" "default" {
  name         = "flask-vm"
  machine_type = "e2-micro"
  zone         = var.gcp_zone
  tags         = ["ssh"]

  boot_disk {
    initialize_params {
      image = "debian-cloud/debian-11"
    }
  }

  ## INSTALL FLASK
  metadata_startup_script = "sudo apt-get update; sudo apt-get install -yq build-essential python3-pip rsync; pip install flask"

  network_interface {
    subnetwork = google_compute_subnetwork.default.id

    access_config {
      # Include this section to give the VM an external IP address
    }
  }
}

## FIREWALL
### SSH
resource "google_compute_firewall" "ssh" {
  name = "allow-ssh"
  allow {
    ports    = ["22"]
    protocol = "tcp"
  }
  direction     = "INGRESS"
  network       = google_compute_network.vpc_network.id
  priority      = 1000
  source_ranges = ["0.0.0.0/0"]
  target_tags   = ["ssh"]
}

### APP
resource "google_compute_firewall" "flask" {
  name    = "flask-app-firewall"
  network = google_compute_network.vpc_network.id

  allow {
    protocol = "tcp"
    ports    = ["5000"]
  }
  source_ranges = ["0.0.0.0/0"]
}

## GET VM PUBLIC IP
output "Web-server-URL" {
 value = join("",["http://",google_compute_instance.default.network_interface.0.access_config.0.nat_ip,":5000"])
}