Remove journald support

radicale/log.py

@@ -20,24 +20,17 @@ Functions to set up Python's logging facility for Radicale's WSGI application.
 
 Log messages are sent to the first available target of:
 
-  - Error stream specified by the WSGI server in wsgi.errors
-  - systemd-journald
-  - stderr
+  - Error stream specified by the WSGI server in "wsgi.errors"
+  - ``sys.stderr``
 
 """
 
 import contextlib
-import io
 import logging
 import os
 import sys
 import threading
 
-try:
-    import systemd.journal
-except ImportError:
-    systemd = None
-
 LOGGER_NAME = "radicale"
 LOGGER_FORMAT = "[%(asctime)s] [%(ident)s] [%(levelname)s] %(message)s"
 DATE_FORMAT = "%Y-%m-%d %H:%M:%S %z"
@@ -71,39 +64,30 @@ class IdentLogRecordFactory:
         return record
 
 
-class ThreadStreamsHandler(logging.Handler):
+class ThreadedStreamHandler(logging.Handler):
+    """Sends logging output to the stream registered for the current thread or
+       ``sys.stderr`` when no stream was registered."""
 
     terminator = "\n"
 
-    def __init__(self, fallback_stream, fallback_handler):
+    def __init__(self):
         super().__init__()
         self._streams = {}
-        self.fallback_stream = fallback_stream
-        self.fallback_handler = fallback_handler
-
-    def setFormatter(self, fmt):
-        super().setFormatter(fmt)
-        self.fallback_handler.setFormatter(fmt)
 
     def emit(self, record):
         try:
-            stream = self._streams.get(threading.get_ident())
-            if stream is None:
-                self.fallback_handler.emit(record)
-            else:
-                msg = self.format(record)
-                stream.write(msg)
-                stream.write(self.terminator)
-                if hasattr(stream, "flush"):
-                    stream.flush()
+            stream = self._streams.get(threading.get_ident(), sys.stderr)
+            msg = self.format(record)
+            stream.write(msg)
+            stream.write(self.terminator)
+            if hasattr(stream, "flush"):
+                stream.flush()
         except Exception:
             self.handleError(record)
 
     @contextlib.contextmanager
     def register_stream(self, stream):
-        if stream == self.fallback_stream:
-            yield
-            return
+        """Register stream for logging output of the current thread."""
         key = threading.get_ident()
         self._streams[key] = stream
         try:
@@ -112,30 +96,16 @@ class ThreadStreamsHandler(logging.Handler):
             del self._streams[key]
 
 
-def get_default_handler():
-    handler = logging.StreamHandler(sys.stderr)
-    # Detect systemd journal
-    with contextlib.suppress(ValueError, io.UnsupportedOperation):
-        journal_dev, journal_ino = map(
-            int, os.environ.get("JOURNAL_STREAM", "").split(":"))
-        st = os.fstat(sys.stderr.fileno())
-        if (systemd and
-                st.st_dev == journal_dev and st.st_ino == journal_ino):
-            handler = systemd.journal.JournalHandler(
-                SYSLOG_IDENTIFIER=LOGGER_NAME)
-    return handler
-
-
 @contextlib.contextmanager
 def register_stream(stream):
-    """Register global errors stream for the current thread."""
+    """Register stream for logging output of the current thread."""
     yield
 
 
 def setup():
     """Set global logging up."""
     global register_stream
-    handler = ThreadStreamsHandler(sys.stderr, get_default_handler())
+    handler = ThreadedStreamHandler()
     logging.basicConfig(format=LOGGER_FORMAT, datefmt=DATE_FORMAT,
                         handlers=[handler])
     register_stream = handler.register_stream