added code to honor --log-cli-level (issue #402)

src/xdist/dsession.py

@@ -15,7 +15,8 @@
     LoadGroupScheduling,
     WorkStealingScheduling,
 )
-
+import logging
+import pickle
 
 from queue import Empty, Queue
 
@@ -286,6 +287,13 @@ def worker_testreport(self, node, rep):
         self.config.hook.pytest_runtest_logreport(report=rep)
         self._handlefailures(rep)
 
+    def worker_runtest_logmessage(self, node, record):
+        record = pickle.loads(record)
+        for handler in logging.getLogger().handlers:
+            process = record.levelno >= handler.level
+            if process:
+                handler.handle(record)
+
     def worker_runtest_protocol_complete(self, node, item_index, duration):
         """
         Emitted when a node fires the 'runtest_protocol_complete' event,

src/xdist/remote.py

@@ -11,6 +11,9 @@
 import os
 import time
 from typing import Any
+import pickle
+import logging
+import copy
 
 import pytest
 from execnet.gateway_base import dumps, DumpError
@@ -56,6 +59,48 @@ def worker_title(title):
         pass
 
 
+class RemoteMessageHandler(logging.Handler):
+    """
+    This handler sends events to a queue. Typically, it would be used together
+    with a multiprocessing Queue to centralise logging to file in one process
+    (in a multi-process application), so as to avoid file write contention
+    between processes.
+
+    This code is new in Python 3.2, but this class can be copy pasted into
+    user code for use with earlier Python versions.
+
+    Largely based on QueueHandler in handlers.py in cpython :
+    Source: https://github.com/python/cpython/blob/8f324b7ecd2df3036fab098c4c8ac185ac07b277/Lib/logging/handlers.py#L1412
+    """
+
+    def __init__(self, queue):
+        """
+        Initialise an instance, using the passed queue.
+        """
+        logging.Handler.__init__(self)
+        self.queue = queue
+
+    def emit(self, record):
+        """
+        Emit a record.
+
+        Writes the LogRecord to the queue, preparing it for pickling first.
+        """
+        try:
+            msg = self.format(record)
+            # bpo-35726: make copy of record to avoid affecting other handlers in the chain.
+            record = copy.copy(record)
+            record.message = msg
+            record.msg = msg
+            record.args = None
+            record.exc_info = None
+            record.exc_text = None
+            x = pickle.dumps(record)
+            self.queue.send_log(x)
+        except Exception:
+            self.handleError(record)
+
+
 class WorkerInteractor:
     SHUTDOWN_MARK = object()
     QUEUE_REPLACED_MARK = object()
@@ -70,6 +115,14 @@ def __init__(self, config, channel):
         self.nextitem_index = None
         config.pluginmanager.register(self)
 
+        # pump cli messages back to master if a level is set
+        if config.option.log_cli_level:
+            rootlog = logging.getLogger()
+            myhandler = RemoteMessageHandler(self)
+            rootlog.addHandler(myhandler)
+            level = logging.getLevelName(config.option.log_cli_level)
+            myhandler.setLevel(level)
+
     def _make_queue(self):
         return self.channel.gateway.execmodel.queue.Queue()
 
@@ -86,6 +139,9 @@ def sendevent(self, name, **kwargs):
         self.log("sending", name, kwargs)
         self.channel.send((name, kwargs))
 
+    def send_log(self, pickled_record):
+        self.sendevent("runtest_logmessage", pickled_record=pickled_record)
+
     @pytest.hookimpl
     def pytest_internalerror(self, excrepr):
         formatted_error = str(excrepr)

src/xdist/workermanage.py

@@ -362,6 +362,8 @@ def process_from_remote(self, eventcall):  # noqa too complex
                 self.notify_inproc(eventname, node=self, ids=kwargs["ids"])
             elif eventname == "runtest_protocol_complete":
                 self.notify_inproc(eventname, node=self, **kwargs)
+            elif eventname == "runtest_logmessage":
+                self.notify_inproc(eventname, node=self, **kwargs)
             elif eventname == "unscheduled":
                 self.notify_inproc(eventname, node=self, **kwargs)
             elif eventname == "logwarning":