[Catalog] Better handling for catalog fetch failure (skypilot-org#1525)

* Handle catalog download failures

* lint

* comments

* lint

Author: romilbhardwaj

sky/clouds/service_catalog/common.py

@@ -99,20 +99,35 @@ def _need_update() -> bool:
             if pull_frequency_hours is not None:
                 update_frequency_str = f' (every {pull_frequency_hours} hours)'
             with backend_utils.safe_console_status(
-                    f'Updating {cloud} catalog{update_frequency_str}'):
+                (f'Updating {cloud} catalog: '
+                 f'{filename}'
+                 f'{update_frequency_str}')) as status:
                 try:
                     r = requests.get(url)
                     r.raise_for_status()
                 except requests.exceptions.RequestException as e:
-                    logger.error(f'Failed to download {cloud} catalog:')
-                    with ux_utils.print_exception_no_traceback():
-                        raise e
-            # Save the catalog to a local file.
-            os.makedirs(os.path.dirname(catalog_path), exist_ok=True)
-            with open(catalog_path, 'w') as f:
-                f.write(r.text)
-            with open(meta_path + '.md5', 'w') as f:
-                f.write(hashlib.md5(r.text.encode()).hexdigest())
+                    ux_utils.console_newline()
+                    status.stop()
+                    error_str = (f'Failed to fetch {cloud} catalog '
+                                 f'{filename}. ')
+                    if os.path.exists(catalog_path):
+                        logger.warning(
+                            f'{error_str}Using cached catalog files.')
+                        # Update catalog file modification time.
+                        os.utime(catalog_path, None)  # Sets to current time
+                    else:
+                        logger.error(
+                            f'{error_str}Please check your internet connection.'
+                        )
+                        with ux_utils.print_exception_no_traceback():
+                            raise e
+                else:
+                    # Download successful, save the catalog to a local file.
+                    os.makedirs(os.path.dirname(catalog_path), exist_ok=True)
+                    with open(catalog_path, 'w') as f:
+                        f.write(r.text)
+                    with open(meta_path + '.md5', 'w') as f:
+                        f.write(hashlib.md5(r.text.encode()).hexdigest())
 
     try:
         df = pd.read_csv(catalog_path)

sky/utils/ux_utils.py

@@ -3,6 +3,18 @@
 import os
 import sys
 
+import rich.console as rich_console
+
+console = rich_console.Console()
+
+
+def console_newline():
+    """Print a newline to the console using rich.
+
+    Useful when catching exceptions inside console.status()
+    """
+    console.print()
+
 
 @contextlib.contextmanager
 def print_exception_no_traceback():