Properly format OT error logs. (#72)

Author: carlosalberto

lightstep/recorder.py

@@ -14,6 +14,7 @@
 import warnings
 
 from basictracer.recorder import SpanRecorder
+from opentracing.logs import ERROR_KIND, STACK
 
 from lightstep.http_converter import HttpConverter
 from lightstep.thrift_converter import ThriftConverter
@@ -157,12 +158,23 @@ def record_span(self, span):
                     self.converter.append_attribute(span_record, key, util._coerce_str(span.tags[key]))
 
         for log in span.logs:
-            self.converter.append_log(span_record, log)
+            self.converter.append_log(span_record, self._normalize_log(log))
 
         with self._mutex:
             if len(self._span_records) < self._max_span_records:
                 self._span_records.append(span_record)
 
+    def _normalize_log(self, log):
+        if log.key_values is not None and len(log.key_values) > 0:
+
+            if ERROR_KIND in log.key_values:
+                log.key_values[ERROR_KIND] = util._format_exc_type(log.key_values[ERROR_KIND])
+
+            if STACK in log.key_values:
+                log.key_values[STACK] = util._format_exc_tb(log.key_values[STACK])
+
+        return log
+
     def flush(self, connection=None):
         """Immediately send unreported data to the server.
 

lightstep/util.py

@@ -3,6 +3,8 @@
 import random
 import sys
 import time
+import traceback
+import types
 import math
 from . import constants
 
@@ -102,3 +104,22 @@ def _coerce_to_unicode(val):
             # Never let these errors bubble up
             return '(encoding error)'
 
+
+def _format_exc_tb(exc_tb):
+    if type(exc_tb) is types.TracebackType:
+        return ''.join(traceback.format_tb(exc_tb))
+
+    return exc_tb
+
+
+def _format_exc_type(exc_type):
+    if exc_type is None:
+        return None
+
+    try:
+        return exc_type.__name__
+    except AttributeError:
+        pass
+
+    # Fallback to the original object.
+    return exc_type