add tests for eventlog

jupyterhub/app.py

@@ -2078,6 +2078,17 @@ def init_pycurl(self):
                 e,
             )
 
+    def init_eventlog(self):
+        """Set up the event logging system."""
+        self.eventlog = EventLog(parent=self)
+
+        for dirname, _, files in os.walk(os.path.join(here, 'event-schemas')):
+            for file in files:
+                if not file.endswith('.yaml'):
+                    continue
+                self.eventlog.register_schema_file(os.path.join(dirname, file))
+
+
     def write_pid_file(self):
         pid = os.getpid()
         if self.pid_file:
@@ -2128,14 +2139,7 @@ def _log_cls(name, cls):
         _log_cls("Authenticator", self.authenticator_class)
         _log_cls("Spawner", self.spawner_class)
 
-        self.eventlog = EventLog(parent=self)
-
-        for dirname, _, files in os.walk(os.path.join(here, 'event-schemas')):
-            for file in files:
-                if not file.endswith('.yaml'):
-                    continue
-                self.eventlog.register_schema_file(os.path.join(dirname, file))
-
+        self.init_eventlog()
         self.init_pycurl()
         self.init_secrets()
         self.init_internal_ssl()

jupyterhub/tests/test_eventlog.py

@@ -0,0 +1,79 @@
+"""Tests for Eventlogging in JupyterHub. 
+
+To test a new schema or event, simply add it to the 
+`valid_events` and `invalid_events` variables below. 
+
+You *shouldn't* need to write new tests.
+"""
+import io
+import json
+import logging
+import jsonschema
+import pytest
+from .mocking import MockHub
+from traitlets.config import Config
+
+
+# To test new schemas, add them to the `valid_events`
+# and `invalid_events` dictionary below.
+
+# To test valid events, add event item with the form:
+# { ( '<schema id>', <version> ) : { <event_data> } }
+valid_events = [
+    ('hub.jupyter.org/server-action', 1, dict(action='start', username='test-username', servername='test-servername')),
+]
+
+# To test invalid events, add event item with the form:
+# { ( '<schema id>', <version> ) : { <event_data> } }
+invalid_events = [
+    # Missing required keys
+    ('hub.jupyter.org/server-action', 1, dict(action='start')),
+]
+
+
+@pytest.fixture
+def get_hub_and_sink():
+    """Get a hub instance with all registered schemas and record an event with it."""
+    # Get a mockhub.
+    hub = MockHub.instance()
+    sink =  io.StringIO()
+    handler = logging.StreamHandler(sink)
+
+    def _record_from_hub(schema):
+        # Update the hub config with handler info.
+        cfg = Config()
+        cfg.EventLog.handlers = [handler]
+        cfg.EventLog.allowed_schemas = [schema]
+
+        # Get hub app.
+        hub.update_config(cfg)
+        hub.init_eventlog()
+
+        # Record an event from the hub.
+        return hub, sink
+
+    yield _record_from_hub
+
+    # teardown
+    hub.clear_instance()
+    handler.flush()
+
+
+@pytest.mark.parametrize('schema, version, event', valid_events)
+def test_valid_events(get_hub_and_sink, schema, version, event):
+    hub, sink = get_hub_and_sink(schema)
+    # Record event.
+    hub.eventlog.record_event(schema, version, event)
+    # Inspect consumed event.
+    output = sink.getvalue()
+    x = json.loads(output)
+
+    assert x is not None
+
+@pytest.mark.parametrize('schema, version, event', invalid_events)
+def test_invalid_events(get_hub_and_sink, schema, version, event):
+    hub, sink = get_hub_and_sink(schema)
+
+    # Make sure an error is thrown when bad events are recorded.
+    with pytest.raises(jsonschema.ValidationError):
+        recorded_event = hub.eventlog.record_event(schema, version, event)