diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 9a81171e5b9f3674e0d413d62d52893cb5cd4304..23d8b4bec9ac7c1e78b14394bf7747d11b99db30 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -3,6 +3,7 @@ class ApplicationController < ActionController::Base
include WithErrors
include WithFeatures
include WithLocale
+ include WithMaintenance
before_action :ensure_university, :authenticate_user!
diff --git a/app/controllers/application_controller/with_maintenance.rb b/app/controllers/application_controller/with_maintenance.rb
new file mode 100644
index 0000000000000000000000000000000000000000..0f28e2325fa2117707a29a36435d63c900a216dd
--- /dev/null
+++ b/app/controllers/application_controller/with_maintenance.rb
@@ -0,0 +1,16 @@
+module ApplicationController::WithMaintenance
+ extend ActiveSupport::Concern
+
+ included do
+ before_action :check_maintenance
+ end
+
+ protected
+
+ def check_maintenance
+ if ENV['MAINTENANCE'] &&
+ current_user&.role != 'server_admin'
+ redirect_to '/maintenance'
+ end
+ end
+end
diff --git a/public/maintenance.html b/public/maintenance.html
new file mode 100644
index 0000000000000000000000000000000000000000..47c8b4c50039385e9508a0381ddd630dfba6c33b
--- /dev/null
+++ b/public/maintenance.html
@@ -0,0 +1,65 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+ <title>Maintenance in progress</title>
+ <meta charset="utf-8">
+ <meta name="viewport" content="width=device-width,initial-scale=1">
+ <meta http-equiv="refresh" content="30;URL=/">
+ <style>
+ body {
+ padding: 15px;
+ }
+
+ * {
+ font-family: sans-serif;
+ font-size: 14px;
+ margin: 0;
+ text-align: center;
+ }
+
+ .dialog {
+ width: 95%;
+ max-width: 22em;
+ margin: calc(50vh - 140px) auto 0;
+ }
+
+ .dialog span {
+ font-size: 150px;
+ font-weight: 900;
+ letter-spacing: -0.04em;
+ display: block;
+ width: 100%;
+ line-height: 0.9;
+ margin-bottom: 50px
+ }
+
+ img {
+ margin-bottom: 30px;
+ }
+
+ h1 {
+ font-size: 14px;
+ line-height: 1.5em;
+ margin-bottom: 30px;
+ }
+
+ h1 em {
+ font-weight: 400;
+ }
+ </style>
+</head>
+
+<body>
+ <div class="dialog">
+ <span>
+ ⌛
+ </span>
+ <div>
+ <h1>Maintenance in progress</h1>
+ <a href="/"><img src="/logo.svg" alt="Osuny" width="100"></a>
+ </div>
+ </div>
+</body>
+
+</html>