diff --git a/template/.env.example b/template/.env.example
index 2f8a563..fbd97d0 100644
--- a/template/.env.example
+++ b/template/.env.example
@@ -26,6 +26,9 @@ DISABLE_PLUGINS_LOCAL=test/test.php
DISABLE_PLUGINS_PREPROD=test/test.php
DISABLE_PLUGINS_PRODUCTION=test/test.php
+MAINTENANCE_ENABLED=true|false
+MAINTENANCE_IPS=127.0.0.1,127.0.0.2
+
AUTH_KEY=''
SECURE_AUTH_KEY=''
LOGGED_IN_KEY=''
diff --git a/template/readme.md b/template/readme.md
index 86384a4..f5fb044 100644
--- a/template/readme.md
+++ b/template/readme.md
@@ -87,6 +87,10 @@ Par défaut, tout ce qui se trouve dans les sous-dossiers de `web/wp-content` es
## Fonctionnalités additionnelles
+### Activation/Désactivation du mode maintenance via variables d'environnement serveur
+
+Le MU-plugin [Studiometa maintenance mode](./web/wp-content/mu-plugins/studiometa-maintenance-mode/README.md) permet d'activer le mode maintenance du site. [Voir le readme](./web/wp-content/mu-plugins/studiometa-maintenance-mode/README.md) pour plus d'informations.
+
### Désactivation de plugins par environnement
Le MU-plugin [Studiometa plugin disabler](./web/wp-content/mu-plugins/studiometa-plugin-disabler/README.md) permet de forcer la désactivation des plugins en fonction de l'environnement. [Voir le readme](./web/wp-content/mu-plugins/studiometa-plugin-disabler/README.md) pour plus d'informations.
diff --git a/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/README.md b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/README.md
new file mode 100644
index 0000000..340fc67
--- /dev/null
+++ b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/README.md
@@ -0,0 +1,14 @@
+# Studio Meta maintenance mode
+
+Put your site under maintenance depends on server environment variables.
+
+## Usage
+
+1. The following server environment variables must be set in order to the maintenance be active:
+```bash
+MAINTENANCE_ENABLED=true|false # Enable/Disable maitenance mode.
+MAINTENANCE_IPS=42.42.42.42.42 # Exclude a list of IPs from maitenance.
+```
+2. You can customize the maintenance page by adding a `maintenance.php` file in `WP_CONTENT_DIR` (see https://developer.wordpress.org/reference/functions/wp_maintenance/). You can find a maintenance page example in [this folder](`./example/maintenance.php`)
+
+> If you use a cache plugin, don't forget to clean caches.
diff --git a/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/example/maintenance.css b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/example/maintenance.css
new file mode 100644
index 0000000..5ce768c
--- /dev/null
+++ b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/example/maintenance.css
@@ -0,0 +1 @@
+h1 { color: red; }
diff --git a/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/example/maintenance.php b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/example/maintenance.php
new file mode 100644
index 0000000..848458e
--- /dev/null
+++ b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/example/maintenance.php
@@ -0,0 +1,24 @@
+
+
+
+>
+
+
+
+ <?php bloginfo( 'name' ) . ( ! empty( get_bloginfo( 'description' ) ) ? ' – ' . bloginfo( 'description' ) : '' ); ?>
+
+
+
+ >
+
+
+
+
diff --git a/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/studiometa-maintenance-mode.php b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/studiometa-maintenance-mode.php
new file mode 100644
index 0000000..061016a
--- /dev/null
+++ b/template/web/wp-content/mu-plugins/studiometa-maintenance-mode/studiometa-maintenance-mode.php
@@ -0,0 +1,104 @@
+
+ * @copyright 2021 Studio Meta
+ * @license https://opensource.org/licenses/MIT
+ * @version 1.0.0
+ */
+
+/**
+ * StudiometaMaintenanceMode class.
+ */
+class StudiometaMaintenanceMode {
+ public function __construct() {
+ add_action( 'wp_loaded', array( $this, 'toggle_maintenance' ) );
+ }
+
+ public function toggle_maintenance() {
+ if ( ! $this->is_maintenance_mode() ) {
+ return;
+ }
+
+ if ( file_exists( WP_CONTENT_DIR . '/maintenance.php' ) ) {
+ $protocol = isset( $_SERVER['SERVER_PROTOCOL'] ) && 'HTTP/1.1' === $_SERVER['SERVER_PROTOCOL'] ? 'HTTP/1.1' : 'HTTP/1.0';
+
+ header( $protocol . ' 503 Service Unavailable', true, 503 );
+ require_once WP_CONTENT_DIR . '/maintenance.php';
+ die();
+ }
+
+ require_once ABSPATH . WPINC . '/functions.php';
+ wp_load_translations_early();
+
+ wp_die(
+ __( 'Briefly unavailable for scheduled maintenance. Check back in a minute.' ),
+ __( 'Maintenance' ),
+ 503
+ );
+ }
+
+ /**
+ * Get the server variable REMOTE_ADDR, or the first ip of HTTP_X_FORWARDED_FOR (when using proxy).
+ *
+ * @return string $remote_addr ip of client
+ */
+ private static function get_remote_addr()
+ {
+ if (function_exists('apache_request_headers')) {
+ $headers = apache_request_headers();
+ } else {
+ $headers = $_SERVER;
+ }
+
+ if (array_key_exists('X-Forwarded-For', $headers)) {
+ $_SERVER['HTTP_X_FORWARDED_FOR'] = $headers['X-Forwarded-For'];
+ }
+
+ if (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && $_SERVER['HTTP_X_FORWARDED_FOR'] && (!isset($_SERVER['REMOTE_ADDR'])
+ || preg_match('/^127\..*/i', trim($_SERVER['REMOTE_ADDR'])) || preg_match('/^172\.16.*/i', trim($_SERVER['REMOTE_ADDR']))
+ || preg_match('/^192\.168\.*/i', trim($_SERVER['REMOTE_ADDR'])) || preg_match('/^10\..*/i', trim($_SERVER['REMOTE_ADDR'])))) {
+ if (strpos($_SERVER['HTTP_X_FORWARDED_FOR'], ',')) {
+ $ips = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
+
+ return $ips[0];
+ } else {
+ return $_SERVER['HTTP_X_FORWARDED_FOR'];
+ }
+ } else {
+ return $_SERVER['REMOTE_ADDR'];
+ }
+ }
+
+ /**
+ * Is maintenance?
+ *
+ * @return boolean Is maintenance?
+ */
+ protected function is_maintenance_mode() {
+ if (
+ 'true' !== getenv( 'MAINTENANCE_ENABLED' )
+ || is_admin()
+ || current_user_can( 'manage_options' )
+ || 'wp-login.php' === $GLOBALS['pagenow']
+ ) {
+ return false;
+ }
+
+ $allowed_ips = explode( ',', getenv( 'MAINTENANCE_IPS' ) );
+
+ if ( $allowed_ips && in_array( $this->get_remote_addr(), $allowed_ips, true ) ) {
+ return false;
+ }
+
+ return true;
+ }
+}
+
+new StudiometaMaintenanceMode();