Disable CORS cache, Fixes: #1445

gns3server/web/web_server.py

@@ -261,15 +261,19 @@ class WebServer:
         # Background task started with the server
         self._app.on_startup.append(self._on_startup)
 
+        resource_options = aiohttp_cors.ResourceOptions(
+            expose_headers="*", allow_headers="*", max_age=0
+        )
+
         # Allow CORS for this domains
         cors = aiohttp_cors.setup(self._app, defaults={
             # Default web server for web gui dev
-            "http://127.0.0.1:8080": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*"),
-            "http://localhost:8080": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*"),
-            "http://127.0.0.1:4200": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*"),
-            "http://localhost:4200": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*"),
-            "http://gns3.github.io": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*"),
-            "https://gns3.github.io": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*")
+            "http://127.0.0.1:8080": resource_options,
+            "http://localhost:8080": resource_options,
+            "http://127.0.0.1:4200": resource_options,
+            "http://localhost:4200": resource_options,
+            "http://gns3.github.io": resource_options,
+            "https://gns3.github.io": resource_options
         })
 
         PortManager.instance().console_host = self._host