diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..5008ddf
Binary files /dev/null and b/.DS_Store differ
diff --git a/terraform/environments/dev/main.tf b/terraform/environments/dev/main.tf
new file mode 100644
index 0000000..ec8f309
--- /dev/null
+++ b/terraform/environments/dev/main.tf
@@ -0,0 +1,28 @@
+# À vous de :
+# 1. Configurer le provider google
+# 2. Appeler les trois modules avec les bonnes variables
+# 3. Créer le fichier de configuration Ansible (template)
+
+terraform {
+  required_providers {
+    google = {
+      source  = "hashicorp/google"
+      version = "~> 6.12.0"
+    }
+  }
+}
+
+provider "google" {
+  project = var.project_id
+  region  = var.region
+}
+
+module "network" {
+  source            = "../../modules/network"
+  project_name      = var.project_name
+  region           = var.region
+  frontend_cidr    = var.frontend_cidr
+  backend_cidr     = var.backend_cidr
+  database_cidr    = var.database_cidr
+  ssh_source_ranges = var.ssh_source_ranges
+}
\ No newline at end of file
diff --git a/terraform/environments/dev/outputs.tf b/terraform/environments/dev/outputs.tf
new file mode 100644
index 0000000..e69de29
diff --git a/terraform/environments/dev/variables.tf b/terraform/environments/dev/variables.tf
new file mode 100644
index 0000000..075accd
--- /dev/null
+++ b/terraform/environments/dev/variables.tf
@@ -0,0 +1,43 @@
+# définissez toutes les variables nécessaires avec des valeurs par défaut appropriées.
+
+variable "project_name" {
+  description = "Nom du projet"
+  type        = string
+  default     = "My First Project"
+}
+
+variable "region" {
+  description = "Region du projet"
+  type        = string
+  default     = "europe-west9"
+}
+
+variable "frontend_cidr" {
+  description = "CIDR for frontend subnet"
+  type        = string
+  default     = "10.0.1.0/24"
+}
+
+variable "backend_cidr" {
+  description = "CIDR for backend subnet"
+  type        = string
+  default     = "10.0.2.0/24"
+}
+
+variable "database_cidr" {
+  description = "CIDR for database subnet"
+  type        = string
+  default     = "10.0.3.0/24"
+}
+
+variable "ssh_source_ranges" {
+  description = ""
+  type        = string
+  default     = "0.0.0.0/0"
+}
+
+variable "project_id" {
+  description = "ID du projet"
+  type        = string
+  default     = "plenary-plane-478713-q1"
+}
\ No newline at end of file
diff --git a/terraform/modules/compute/main.tf b/terraform/modules/compute/main.tf
new file mode 100644
index 0000000..a4f4814
--- /dev/null
+++ b/terraform/modules/compute/main.tf
@@ -0,0 +1,22 @@
+# À vous de créer :
+
+# 1. Instance frontend :
+#    - Image : debian-11
+#    - Disque : 10GB
+#    - IP publique
+#    - Tags : frontend, ssh
+#    - OS Login enabled
+
+# 2. Instance backend :
+#    - Image : debian-11
+#    - Disque : 10GB
+#    - Pas d'IP publique (interne seulement)
+#    - Tags : backend, ssh
+#    - OS Login enabled
+
+# 3. Instance database :
+#    - Image : debian-11
+#    - Disque : 20GB
+#    - Pas d'IP publique
+#    - Tags : database, ssh
+#    - OS Login enabled
\ No newline at end of file
diff --git a/terraform/modules/compute/outputs.tf b/terraform/modules/compute/outputs.tf
new file mode 100644
index 0000000..4a91aa9
--- /dev/null
+++ b/terraform/modules/compute/outputs.tf
@@ -0,0 +1,4 @@
+# À vous d'exposer :
+# 1. Les IPs internes de toutes les instances
+# 2. L'IP publique du frontend
+# 3. Les noms des instances
\ No newline at end of file
diff --git a/terraform/modules/compute/variables.tf b/terraform/modules/compute/variables.tf
new file mode 100644
index 0000000..76a14cc
--- /dev/null
+++ b/terraform/modules/compute/variables.tf
@@ -0,0 +1,6 @@
+# À vous de définir les variables pour :
+# - instance_type
+# - zone
+# - frontend_subnet_id
+# - backend_subnet_id
+# - database_subnet_id
\ No newline at end of file
diff --git a/terraform/modules/iam/main.tf b/terraform/modules/iam/main.tf
new file mode 100644
index 0000000..a4b77c1
--- /dev/null
+++ b/terraform/modules/iam/main.tf
@@ -0,0 +1,5 @@
+# À vous de créer :
+# 1. Un compte de service pour Terraform
+# 2. Une clé pour ce compte de service
+# 3. Les rôles IAM nécessaires
+# 4. La configuration OS Login avec votre clé SSH
\ No newline at end of file
diff --git a/terraform/modules/iam/outputs.tf b/terraform/modules/iam/outputs.tf
new file mode 100644
index 0000000..c73acc0
--- /dev/null
+++ b/terraform/modules/iam/outputs.tf
@@ -0,0 +1,3 @@
+# À vous d'exposer :
+# 1. L'email du compte de service
+# 2. La clé du compte de service (sensitive = true)
\ No newline at end of file
diff --git a/terraform/modules/iam/variables.tf b/terraform/modules/iam/variables.tf
new file mode 100644
index 0000000..5ac1614
--- /dev/null
+++ b/terraform/modules/iam/variables.tf
@@ -0,0 +1,2 @@
+# À vous de définir :
+# - project_id (string)
\ No newline at end of file
diff --git a/terraform/modules/network/main.tf b/terraform/modules/network/main.tf
new file mode 100644
index 0000000..25062bd
--- /dev/null
+++ b/terraform/modules/network/main.tf
@@ -0,0 +1,88 @@
+# À vous de créer :
+# 1. Un VPC personnalisé avec auto_create_subnetworks = false
+# 2. Trois sous-réseaux (frontend, backend, database)
+# 3. Règles de firewall :
+#    - HTTP/HTTPS vers frontend
+#    - SSH vers toutes les instances
+#    - Port 8000 de frontend vers backend
+#    - Port 3306 de backend vers database
+
+# VPC
+resource "google_compute_network" "vpc_terraform" {
+  name                    = "vpc-terraform"
+  auto_create_subnetworks = false
+}
+
+# Sous-réseau
+resource "google_compute_subnetwork" "subnet_frontend" {
+  name          = "frontend"
+  network       = google_compute_network.vpc_terraform.id
+  ip_cidr_range = var.frontend_cidr
+  region        = var.region
+}
+
+resource "google_compute_subnetwork" "subnet_backend" {
+  name          = "backend"
+  network       = google_compute_network.vpc_terraform.id
+  ip_cidr_range = var.backend_cidr
+  region        = var.region
+}
+
+resource "google_compute_subnetwork" "subnet_database" {
+  name          = "database"
+  network       = google_compute_network.vpc_terraform.id
+  ip_cidr_range = var.database_cidr
+  region        = var.region
+}
+
+resource "google_compute_firewall" "allow_user_frontend" {
+  name    = "allow-user-frontend"
+  network = google_compute_network.vpc_terraform.id
+
+  allow {
+    protocol = "tcp"
+    ports    = ["80", "443"]
+  }
+
+  source_ranges = ["0.0.0.0/0"]
+  target_tags   = ["frontend"]
+}
+
+resource "google_compute_firewall" "allow_frontend_backend" {
+  name    = "allow-frontend-backend"
+  network = google_compute_network.vpc_terraform.id
+
+  allow {
+    protocol = "tcp"
+    ports    = ["8000"]
+  }
+
+  source_tags = ["frontend"]
+  target_tags   = ["backend"]
+}
+
+resource "google_compute_firewall" "allow_ssh_all" {
+  name    = "allow-ssh-all"
+  network = google_compute_network.vpc_terraform.id
+
+  allow {
+    protocol = "tcp"
+    ports    = ["22"]
+  }
+
+  source_ranges = ["0.0.0.0/0"]
+  target_tags   = ["ssh"]
+}
+
+resource "google_compute_firewall" "allow_backend_database" {
+  name    = "allow-backend-database"
+  network = google_compute_network.vpc_terraform.id
+
+  allow {
+    protocol = "tcp"
+    ports    = ["3306"]
+  }
+
+  source_tags = ["backend"]
+  target_tags   = ["database"]
+}
\ No newline at end of file
diff --git a/terraform/modules/network/outputs.tf b/terraform/modules/network/outputs.tf
new file mode 100644
index 0000000..078bc94
--- /dev/null
+++ b/terraform/modules/network/outputs.tf
@@ -0,0 +1,15 @@
+# À vous d'exposer :
+# 1. L'ID du VPC
+# 2. Les IDs des sous-réseaux sous forme de map
+
+output "vpc_terraform_output" {
+  value = google_compute_network.vpc_terraform.id
+}
+
+output "list_id" {
+    value = {
+        frontend = google_compute_subnetwork.subnet_frontend.id
+        backend = google_compute_subnetwork.subnet_backend.id
+        database = google_compute_subnetwork.subnet_database.id
+    }
+}
\ No newline at end of file
diff --git a/terraform/modules/network/variables.tf b/terraform/modules/network/variables.tf
new file mode 100644
index 0000000..36786d4
--- /dev/null
+++ b/terraform/modules/network/variables.tf
@@ -0,0 +1,37 @@
+# À vous de définir les variables pour :
+# - project_name (string)
+# - region (string)
+# - frontend_cidr (string)
+# - backend_cidr (string)
+# - database_cidr (string)
+# - ssh_source_ranges (string)
+
+variable "project_name" {
+  description = "Nom du projet"
+  type        = string
+}
+
+variable "region" {
+  description = "Region du projet"
+  type        = string
+}
+
+variable "frontend_cidr" {
+  description = "CIDR for frontend subnet"
+  type        = string
+}
+
+variable "backend_cidr" {
+  description = "CIDR for backend subnet"
+  type        = string
+}
+
+variable "database_cidr" {
+  description = "CIDR for database subnet"
+  type        = string
+}
+
+variable "ssh_source_ranges" {
+  description = ""
+  type        = string
+}
\ No newline at end of file