Limit size of logs sent to GitHub (#1760)

Share sent bytes across handler wrappers

Resolves #1494

Author: ericvergnaud

src/databricks/labs/ucx/installer/workflows.py

@@ -727,6 +727,7 @@ class MaxedStreamHandler(logging.StreamHandler):
 
     MAX_STREAM_SIZE = 2**20 - 2**6  # 1 Mb minus some buffer
     _installed_handlers: dict[str, tuple[logging.Logger, MaxedStreamHandler]] = {}
+    _sent_bytes = 0
 
     @classmethod
     def install_handler(cls, logger_: logging.Logger):
@@ -738,7 +739,7 @@ def install_handler(cls, logger_: logging.Logger):
             # any handler to override ?
             handler = next((h for h in logger_.handlers if isinstance(h, logging.StreamHandler)), None)
             if handler:
-                to_install = MaxedStreamHandler(cls.MAX_STREAM_SIZE, handler)
+                to_install = MaxedStreamHandler(handler)
                 cls._installed_handlers[logger_.name] = (logger_, to_install)
                 logger_.removeHandler(handler)
                 logger_.addHandler(to_install)
@@ -750,17 +751,14 @@ def install_handler(cls, logger_: logging.Logger):
 
     @classmethod
     def uninstall_handlers(cls):
-        for pair in cls._installed_handlers.values():
-            logger_ = pair[0]
-            handler = pair[1]
+        for logger_, handler in cls._installed_handlers.values():
             logger_.removeHandler(handler)
             logger_.addHandler(handler.original_handler)
         cls._installed_handlers.clear()
+        cls._sent_bytes = 0
 
-    def __init__(self, max_bytes: int, original_handler: logging.StreamHandler):
+    def __init__(self, original_handler: logging.StreamHandler):
         super().__init__()
-        self._max_bytes = max_bytes
-        self._sent_bytes = 0
         self._original_handler = original_handler
 
     @property
@@ -784,7 +782,7 @@ def emit(self, record):
 
     def _prevent_overflow(self, msg: str):
         data = msg.encode("utf-8")
-        if self._sent_bytes + len(data) > self._max_bytes:
+        if self._sent_bytes + len(data) > self.MAX_STREAM_SIZE:
             # ensure readers are aware of why the logs are incomplete
             self.stream.write(f"MAX LOGS SIZE REACHED: {self._sent_bytes} bytes!!!")
             self.flush()