disable caching in lightly-serve (#1507)

closes lig-4625
- disables caching for lightly-serve. This mitigates issues where the browser gets a 404 from lightly-serve due to wrong setup/configuration and caches the result even though the lightly-serve got fixed.
- also added link to the docs and added some colors (see screenshot)

lightly/api/serve.py

@@ -40,6 +40,13 @@ def do_OPTIONS(self) -> None:
             self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
             self.end_headers()
 
+        def send_response_only(self, code, message=None):
+            super().send_response_only(code, message)
+            self.send_header(
+                "Cache-Control", "no-store, must-revalidate, no-cache, max-age=-1"
+            )
+            self.send_header("Expires", "0")
+
     return HTTPServer((host, port), _LocalDatasourceRequestHandler)
 
 

lightly/cli/serve_cli.py

@@ -5,6 +5,7 @@
 
 from lightly.api import serve
 from lightly.cli._helpers import fix_hydra_arguments
+from lightly.utils.hipify import bcolors
 
 
 @hydra.main(**fix_hydra_arguments(config_path="config", config_name="lightly-serve"))
@@ -39,8 +40,15 @@ def lightly_serve(cfg):
         host=cfg.host,
         port=cfg.port,
     )
-    print(f"Starting server, listening at '{httpd.server_name}:{httpd.server_port}'")
-    print(f"Serving files in '{cfg.input_mount}' and '{cfg.lightly_mount}'")
+    print(
+        f"Starting server, listening at '{bcolors.OKBLUE}{httpd.server_name}:{httpd.server_port}{bcolors.ENDC}'"
+    )
+    print(
+        f"Serving files in '{bcolors.OKBLUE}{cfg.input_mount}{bcolors.ENDC}' and '{bcolors.OKBLUE}{cfg.lightly_mount}{bcolors.ENDC}'"
+    )
+    print(
+        f"Please follow our docs if you are facing any issues: https://docs.lightly.ai/docs/local-storage#optional-after-run-view-local-data-in-lightly-platform"
+    )
     httpd.serve_forever()