terraform/modules/network/main.tf

resource "google_compute_network" "vpc" {
  name                    = "vpc-terra"
  auto_create_subnetworks = false
}

resource "google_compute_subnetwork" "front" {
  name          = "frontend"
  network       = google_compute_network.vpc.id
  ip_cidr_range = "10.0.1.0/24"
  region        = "europe-west1-b"
}

resource "google_compute_subnetwork" "backend" {
  name          = "backend"
  network       = google_compute_network.vpc.id
  ip_cidr_range = "10.0.2.0/24"
  region        = "europe-west1-b"
}

resource "google_compute_subnetwork" "database" {
  name          = "database"
  network       = google_compute_network.vpc.id
  ip_cidr_range = "10.0.3.0/24"
  region        = "europe-west1"
}

resource "google_compute_firewall" "allow_http" {
  name    = "allow-http"
  network = google_compute_network.vpc.id

  allow {
    protocol = "tcp"
    ports    = ["80", "443"]
  }
  target_tags   = ["frontend"]
}

resource "google_compute_firewall" "allow_ssh" {
  name    = "allow-ssh"
  network = google_compute_network.vpc.id

  allow {
    protocol = "tcp"
    ports    = ["22"]
  }
source_ranges = [var.ssh_source_ranges]

}


resource "google_compute_firewall" "front-to-back" {
  name    = "front-to-back"
  network = google_compute_network.vpc.id

  allow {
    protocol = "tcp"
    ports    = ["8000"]
  }
  source_ranges = [ var.frontend_cidr ]
  target_tags   = ["backend"]
}

resource "google_compute_firewall" "back-to-data" {
  name    = "back-to-data"
  network = google_compute_network.vpc.id

  allow {
    protocol = "tcp"
    ports    = ["3306"]
  }
  source_ranges = [ var.backend_cidr ]
  target_tags   = ["database"]
}