fix: Add zone parameter to scaleway_instance_private_nic data source for multi-zone deployments (#72)

The scaleway_instance_private_nic data source was missing the zone parameter, which could cause issues when deploying instances across multiple zones.
This fix ensures the private NIC data source uses the same zone as the instance.

Signed-off-by: marc <[email protected]>

Author: maathor

examples/multi-zones/README.md

@@ -0,0 +1,73 @@
+# Multi-Zones Instance Deployment Example
+
+This example demonstrates how to deploy instances across multiple Scaleway availability zones using the `terraform-scaleway-instance` module.
+
+## Overview
+
+This configuration creates two instances in different availability zones (`fr-par-1` and `fr-par-2`) with their respective security groups. This example showcases the module's ability to handle multi-zone deployments correctly, particularly with the fix for the `scaleway_instance_private_nic` data source that now properly includes the zone parameter.
+
+## Architecture
+
+- **Instance 0**: Deployed in `fr-par-1` zone
+- **Instance 1**: Deployed in `fr-par-2` zone
+- **Security Groups**: One per zone to ensure proper network isolation
+- **Instance Type**: PLAY2-NANO (2 vCPU, 8GB RAM)
+- **Image**: Debian Bookworm
+
+## Key Features
+
+### Zone-Aware Configuration
+
+The example uses a local configuration to define instances across zones:
+
+```hcl
+locals {
+  instances = {
+    "0" = {
+      name = "instance-0"
+      zone = "fr-par-1"
+    }
+    "1" = {
+      name = "instance-1"
+      zone = "fr-par-2"
+    }
+  }
+}
+```
+
+### Dynamic Security Group Creation
+
+Security groups are created dynamically for each unique zone:
+
+```hcl
+resource "scaleway_instance_security_group" "instances_security_group" {
+  for_each = local.unique_zones
+  
+  zone = each.value
+  # ... other configuration
+}
+```
+
+## Usage
+
+1. Initialize Terraform:
+   ```bash
+   terraform init
+   ```
+
+2. Plan the deployment:
+   ```bash
+   terraform plan
+   ```
+
+3. Apply the configuration:
+   ```bash
+   terraform apply
+   ```
+
+## Files
+
+- `main.tf`: Main configuration with instance and security group definitions
+- `versions.tf`: Terraform and provider version constraints
+
+This example validates that the module correctly handles multi-zone deployments and demonstrates best practices for zone-aware infrastructure deployment on Scaleway.

examples/multi-zones/main.tf

@@ -0,0 +1,69 @@
+locals {
+  instances = {
+    "0" = {
+      name = "instance-0"
+      zone = "fr-par-1"
+    }
+    "1" = {
+      name = "instance-1"
+      zone = "fr-par-2"
+    }
+  }
+  unique_zones = toset([
+    for instance in local.instances : instance.zone
+  ])
+}
+
+module "instances" {
+  source = "../../"
+
+  for_each = local.instances
+
+  instance_type = "PLAY2-NANO" # 2 vCPU, 8GB RAM
+  image         = "debian_bookworm"
+
+  # Network
+  private_networks  = []
+  security_group_id = scaleway_instance_security_group.instances_security_group[each.value.zone].id
+  zone              = each.value.zone
+
+  additional_volume_ids = null
+
+  # Naming
+  hostname = each.value.name
+
+  # IPs
+  enable_ipv6        = false
+  enable_public_ipv4 = true
+}
+
+resource "scaleway_instance_security_group" "instances_security_group" {
+  for_each = local.unique_zones
+
+  name = "instance-sg"
+
+  # Default policies - drop everything except explicitly allowed
+  inbound_default_policy  = "drop"
+  outbound_default_policy = "accept"
+  zone                    = each.value
+
+  inbound_rule {
+    action   = "accept"
+    port     = 22
+    ip_range = "0.0.0.0/22"
+  }
+
+  # Outbound rules - allow all traffic out
+  outbound_rule {
+    action     = "accept"
+    port_range = "1-65535"
+    ip_range   = "0.0.0.0/0"
+  }
+
+  outbound_rule {
+    action     = "accept"
+    protocol   = "UDP"
+    port_range = "1-65535"
+    ip_range   = "0.0.0.0/0"
+  }
+}

examples/multi-zones/versions.tf

@@ -0,0 +1,11 @@
+terraform {
+  required_providers {
+    scaleway = {
+      source  = "scaleway/scaleway"
+      version = "~> 2.59"
+    }
+  }
+  required_version = "~> 1.10"
+}
+
+provider "scaleway" {}

ipv4.tf

@@ -34,6 +34,7 @@ data "scaleway_instance_private_nic" "this" {
 
   server_id          = scaleway_instance_server.this.id
   private_network_id = var.private_networks[count.index]
+  zone               = var.zone
 }