Add support for JSON formatted logs

notebook/log.py

@@ -10,7 +10,7 @@
 from .prometheus.log_functions import prometheus_log_method
 
 
-def log_request(handler):
+def log_request(handler, log=access_log, log_json=False):
     """log a bit more information about each request than tornado's default
     
     - move static file get success to debug-level (reduces noise)
@@ -22,29 +22,35 @@ def log_request(handler):
     request = handler.request
     if status < 300 or status == 304:
         # Successes (or 304 FOUND) are debug-level
-        log_method = access_log.debug
+        log_method = log.debug
     elif status < 400:
-        log_method = access_log.info
+        log_method = log.info
     elif status < 500:
-        log_method = access_log.warning
+        log_method = log.warning
     else:
-        log_method = access_log.error
+        log_method = log.error
 
-    request_time = 1000.0 * handler.request.request_time()
+    request_time = 1000.0 * request.request_time()
     ns = dict(
         status=status,
         method=request.method,
         ip=request.remote_ip,
         uri=request.uri,
-        request_time=request_time,
+        request_time=float('%.2f' % request_time),
     )
-    msg = "{status} {method} {uri} ({ip}) {request_time:.2f}ms"
+    msg = "{status} {method} {uri} ({ip}) {request_time:f}ms"
     if status >= 400:
         # log bad referers
         ns['referer'] = request.headers.get('Referer', 'None')
         msg = msg + ' referer={referer}'
     if status >= 500 and status != 502:
         # log all headers if it caused an error
-        log_method(json.dumps(dict(request.headers), indent=2))
-    log_method(msg.format(**ns))
+        if log_json:
+            log_method("", extra=dict(props=dict(request.headers)))
+        else:
+            log_method(json.dumps(dict(request.headers), indent=2))
+    if log_json:
+        log_method("", extra=dict(props=ns))
+    else:
+        log_method(msg.format(**ns))
     prometheus_log_method(handler)

notebook/notebookapp.py

@@ -8,6 +8,7 @@
 import binascii
 import datetime
 import errno
+import functools
 import gettext
 import hashlib
 import hmac
@@ -247,9 +248,12 @@ def init_settings(self, jupyter_app, kernel_manager, contents_manager,
             # collapse $HOME to ~
             root_dir = '~' + root_dir[len(home):]
 
+        # Use the NotebookApp logger and its formatting for tornado request logging.
+        log_function = functools.partial(
+            log_request, log=log, log_json=jupyter_app.log_json)
         settings = dict(
             # basics
-            log_function=log_request,
+            log_function=log_function,
             base_url=base_url,
             default_url=default_url,
             template_path=template_path,
@@ -701,6 +705,43 @@ class NotebookApp(JupyterApp):
 
     _log_formatter_cls = LogFormatter
 
+    _json_logging_import_error_logged = False
+
+    log_json = Bool(False, config=True,
+        help=_('Set to True to enable JSON formatted logs. '
+               'Run "pip install notebook[json-logging]" to install the '
+               'required dependent packages. Can also be set using the '
+               'environment variable JUPYTER_ENABLE_JSON_LOGGING=true.')
+    )
+
+    @default('log_json')
+    def _default_log_json(self):
+        """Get the log_json value from the environment."""
+        return os.getenv('JUPYTER_ENABLE_JSON_LOGGING', 'false').lower() == 'true'
+
+    @validate('log_json')
+    def _validate_log_json(self, proposal):
+        # If log_json=True, see if the json_logging package can be imported and
+        # override _log_formatter_cls if so.
+        value = proposal['value']
+        if value:
+            try:
+                import json_logging
+                self.log.debug('initializing json logging')
+                json_logging.init_non_web(enable_json=True)
+                self._log_formatter_cls = json_logging.JSONLogFormatter
+            except ImportError:
+                # If configured for json logs and we can't do it, log a hint.
+                # Only log the error once though.
+                if not self._json_logging_import_error_logged:
+                    self.log.warning(
+                        'Unable to use json logging due to missing packages. '
+                        'Run "pip install notebook[json-logging]" to fix.'
+                    )
+                    self._json_logging_import_error_logged = True
+                value = False
+        return value
+
     @default('log_level')
     def _default_log_level(self):
         return logging.INFO

notebook/tests/test_log.py

@@ -0,0 +1,40 @@
+import unittest
+from unittest import mock
+
+from notebook import log
+
+
+class TestLogRequest(unittest.TestCase):
+
+    @mock.patch('notebook.log.prometheus_log_method')
+    def test_log_request_json(self, mock_prometheus):
+        headers = {'Referer': 'test'}
+        request = mock.Mock(
+            request_time=mock.Mock(return_value=1),
+            headers=headers,
+            method='GET',
+            remote_ip='1.2.3.4',
+            uri='/notebooks/foo/bar'
+        )
+        handler = mock.MagicMock(
+            request=request,
+            get_status=mock.Mock(return_value=500)
+        )
+        logger = mock.MagicMock()
+        log.log_request(handler, log=logger, log_json=True)
+        # Since the status was 500 there should be two calls to log.error,
+        # one with the request headers and another with the other request
+        # parameters.
+        self.assertEqual(2, logger.error.call_count)
+        logger.error.assert_has_calls([
+            mock.call("", extra=dict(props=dict(headers))),
+            mock.call("", extra=dict(props={
+                'status': handler.get_status(),
+                'method': request.method,
+                'ip': request.remote_ip,
+                'uri': request.uri,
+                'request_time': 1000.0,
+                'referer': headers['Referer']
+            }))
+        ])
+        mock_prometheus.assert_called_once_with(handler)

notebook/tests/test_notebookapp.py

@@ -190,6 +190,12 @@ def test_list_running_servers(self):
         assert len(servers) >= 1
         assert self.port in {info['port'] for info in servers}
 
+    def test_log_json_default(self):
+        self.assertFalse(self.notebook.log_json)
+
+    def test_validate_log_json(self):
+        self.assertFalse(self.notebook._validate_log_json(dict(value=False)))
+
 
 # UNIX sockets aren't available on Windows.
 if not sys.platform.startswith('win'):
@@ -201,3 +207,29 @@ def test_list_running_sock_servers(self):
             servers = list(notebookapp.list_running_servers())
             assert len(servers) >= 1
             assert self.sock in {info['sock'] for info in servers}
+
+
+class NotebookAppJSONLoggingTests(NotebookTestBase):
+    """Tests for when json logging is enabled."""
+    @classmethod
+    def setup_class(cls):
+        super(NotebookAppJSONLoggingTests, cls).setup_class()
+        try:
+            import json_logging
+            cls.json_logging_available = True
+        except ImportError:
+            cls.json_logging_available = False
+
+    @classmethod
+    def get_patch_env(cls):
+        test_env = super(NotebookAppJSONLoggingTests, cls).get_patch_env()
+        test_env.update({'JUPYTER_ENABLE_JSON_LOGGING': 'true'})
+        return test_env
+
+    def test_log_json_enabled(self):
+        self.assertTrue(self.notebook._default_log_json())
+
+    def test_validate_log_json(self):
+        self.assertEqual(
+            self.notebook._validate_log_json(dict(value=True)),
+            self.json_logging_available)

setup.py

@@ -119,6 +119,7 @@
                  'nbval', 'nose-exclude', 'selenium', 'pytest', 'pytest-cov'],
         'docs': ['sphinx', 'nbsphinx', 'sphinxcontrib_github_alt', 'sphinx_rtd_theme'],
         'test:sys_platform != "win32"': ['requests-unixsocket'],
+        'json-logging': ['json-logging']
     },
     python_requires = '>=3.5',
     entry_points = {