Manage exceptions better

src/main.py

@@ -1,8 +1,15 @@
+"""
+Mastodon welcome bot. Listens for notifications regarding new singups,
+and sends a welcome message to the new user.
+"""
+
 import logging
 import sys
 import toml  # Used for the config file parsing
 from mastodon import Mastodon, StreamListener
-from mastodon.errors import MastodonError
+from mastodon.errors import MastodonError, MastodonNetworkError
+import requests
+import time
 
 logger = logging.getLogger(__name__)
 
@@ -52,12 +59,16 @@ class BotListener(StreamListener):
             else:
                 logger.debug("Notification type: %s", kind)
 
-        except Exception:
+        except MastodonError:
             # Keep one failed response from interrupting notification handling.
             logger.exception("Failed to handle notification")
 
 
 def main():
+    """
+    Setup loggin, configuration and connexion to Mastodon
+    Then, run the bot via a Listener
+    """
     logging.basicConfig(
         filename="botato.log",
         level=logging.DEBUG,
@@ -67,16 +78,26 @@ def main():
     try:
         with open("config/botato.toml", "r", encoding="utf-8") as f:
             configuration = toml.load(f)
+        logger.debug("Loaded configuration file")
     except (OSError, toml.TomlDecodeError, TypeError):
-        logger.exception("Unable to load config/configuration file")
+        logger.exception("Unable to load configuration file")
         sys.exit(1)
 
-    mastodon = Mastodon(
-        api_base_url=configuration["mastodon"]["instance"],
-        access_token=configuration["mastodon"]["access_token"],
-    )
+    # while not connected:
+    logger.debug("Trying to start the bot...")
+    try:
+        # comment:
+        mastodon = Mastodon(
+            api_base_url=configuration["mastodon"]["instance"],
+            access_token=configuration["mastodon"]["access_token"],
+        )
+    except Exception:
+        logger.exception("Unable to connect to the Mastodon instance")
 
-    listener = BotListener(mastodon, configuration["messages"])
+    try:
+        listener = BotListener(mastodon, configuration["messages"])
+    except Exception:
+        logger.exception("Unable to start the listener for the bot's notifications")
 
     try:
         # Blocking call: runs until interrupted or the connection fails.
@@ -84,10 +105,21 @@ def main():
         mastodon.stream_user(listener)
     except KeyboardInterrupt:
         logger.info("Stopping bot")
-    except MastodonError:
-        logger.exception("Mastodon streaming error")
-        raise
-
+        sys.exit(0)
+    except MastodonError as e:
+        if "Unauthorized" in e:
+            logger.error("The connexion to the instance is unauthorized, are you sure your access token is valid ? ")
+        else:
+            logger.error("Mastodon streaming error : %s", str(e))
+        sys.exit(1)
+    except requests.exceptions.ConnectionError:
+        logger.error("Unable to connect to the instance : Are you sure you're connected to the Internet is the URL in the configuration file is good ? ")
+    except MastodonNetworkError as e:
+        logger.error("Error while connecting to the server %s", str(e))
+        sys.exit(1)
+    # else:
+    #     logger.error("Unable to start streaming the bot's notifications...")
+    #     sys.exit(1)
 
 if __name__ == "__main__":
     main()