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

// 1. VPC personnalisé
resource "google_compute_network" "vpc" {
  name                    = "${var.project_name}-vpc"
  project                 = var.project_name
  auto_create_subnetworks = false
}

// 2. Sous-réseaux

resource "google_compute_subnetwork" "frontend" {
  name          = "${var.project_name}-frontend-subnet"
  project       = var.project_name
  region        = var.region
  network       = google_compute_network.vpc.id
  ip_cidr_range = var.frontend_cidr
}

resource "google_compute_subnetwork" "backend" {
  name          = "${var.project_name}-backend-subnet"
  project       = var.project_name
  region        = var.region
  network       = google_compute_network.vpc.id
  ip_cidr_range = var.backend_cidr
}

resource "google_compute_subnetwork" "database" {
  name          = "${var.project_name}-database-subnet"
  project       = var.project_name
  region        = var.region
  network       = google_compute_network.vpc.id
  ip_cidr_range = var.database_cidr
}

// 3. Règles de firewall

// 3.1 HTTP/HTTPS vers frontend (depuis Internet)
resource "google_compute_firewall" "frontend_http_https" {
  name    = "${var.project_name}-fw-frontend-http-https"
  project = var.project_name
  network = google_compute_network.vpc.name

  description = "Autorise HTTP/HTTPS vers les instances frontend"

  direction = "INGRESS"

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

  source_ranges = ["0.0.0.0/0"]

  // Les instances frontend devront avoir ce tag
  target_tags = ["frontend"]
}

// 3.2 SSH vers toutes les instances (depuis la plage fournie)
resource "google_compute_firewall" "ssh_all" {
  name    = "${var.project_name}-fw-ssh-all"
  project = var.project_name
  network = google_compute_network.vpc.name

  description = "Autorise SSH vers toutes les instances du VPC"

  direction = "INGRESS"

  allow {
    protocol = "tcp"
    ports    = ["22"]
  }

  // Une seule CIDR passée en string, on l'enferme dans une liste
  source_ranges = [var.ssh_source_ranges]
}

// 3.3 Port 8000 de frontend vers backend
resource "google_compute_firewall" "frontend_to_backend_8000" {
  name    = "${var.project_name}-fw-frontend-backend-8000"
  project = var.project_name
  network = google_compute_network.vpc.name

  description = "Autorise le trafic TCP 8000 des instances frontend vers backend"

  direction = "INGRESS"

  allow {
    protocol = "tcp"
    ports    = ["8000"]
  }

  // Le trafic vient des instances taguées 'frontend'
  source_tags = ["frontend"]

  // Et cible les instances taguées 'backend'
  target_tags = ["backend"]
}

// 3.4 Port 3306 de backend vers database
resource "google_compute_firewall" "backend_to_database_3306" {
  name    = "${var.project_name}-fw-backend-database-3306"
  project = var.project_name
  network = google_compute_network.vpc.name

  description = "Autorise le trafic TCP 3306 des instances backend vers database"

  direction = "INGRESS"

  allow {
    protocol = "tcp"
    ports    = ["3306"]
  }

  source_tags = ["backend"]
  target_tags = ["database"]
}