log a debug message if accessing request.body fails (#380)

closes #380

Author: beniwohli

elasticapm/contrib/django/client.py

@@ -115,7 +115,8 @@ def get_data_from_request(self, request, capture_body=False):
             else:
                 try:
                     data = request.body
-                except Exception:
+                except Exception as e:
+                    self.logger.debug("Can't capture request body: %s", compat.text_type(e))
                     data = "<unavailable>"
 
             result["body"] = data if (capture_body or not data) else "[REDACTED]"

tests/contrib/django/django_tests.py

@@ -550,6 +550,19 @@ def test_post_raw_data(django_elasticapm_client):
         assert request["body"] == "[REDACTED]"
 
 
+def test_post_read_error_logging(django_elasticapm_client, caplog, rf):
+    request = rf.post("/test", data="{}", content_type="application/json")
+
+    def read():
+        raise IOError("foobar")
+
+    request.read = read
+    with caplog.at_level(logging.DEBUG):
+        django_elasticapm_client.get_data_from_request(request, capture_body=True)
+    record = caplog.records[0]
+    assert record.message == "Can't capture request body: foobar"
+
+
 @pytest.mark.skipif(django.VERSION < (1, 9), reason="get-raw-uri-not-available")
 def test_disallowed_hosts_error_django_19(django_elasticapm_client):
     request = WSGIRequest(