Add fallback nginx host

basic/etc/nginx/conf.d/default.conf

@@ -36,3 +36,26 @@ server {
         return 200 "vm-pong";
     }
 }
+
+server {
+    listen [::]:443 ssl http2;
+    server_name ~^(.*)\.spotter\.vm$;
+
+    location / {
+        return 503;
+    }
+
+    location /static {
+        root /usr/share/vmmgr;
+    }
+
+    error_page 503 /503.html;
+    location = /503.html {
+        root /usr/share/vmmgr/templates;
+    }
+
+    location = /vm-ping {
+        add_header Content-Type text/plain;
+        return 200 "vm-pong";
+    }
+}