try to fix flaky appveyor tests (#259)

test_urllib3 is quite flaky on appveyor. The assumption is that due to
the slow executor machine, the http server used in this test isn't
quick enough to boot up. Now we wait for the server to boot up.

closes #259

Signed-off-by: Benjamin Wohlwend <[email protected]>

Author: beniwohli

conftest.py

@@ -3,7 +3,8 @@
 from os.path import abspath, dirname, join
 
 from tests.fixtures import (elasticapm_client, instrument, not_so_random,
-                            sending_elasticapm_client, validating_httpserver)
+                            sending_elasticapm_client, validating_httpserver,
+                            waiting_httpserver)
 from tests.utils.compat import middleware_setting
 
 try:

tests/fixtures.py

@@ -2,6 +2,8 @@
 import json
 import os
 import random
+import socket
+import time
 import zlib
 
 import jsonschema
@@ -94,10 +96,17 @@ def elasticapm_client(request):
     client.close()
 
 
+@pytest.fixture()
+def waiting_httpserver(httpserver):
+    wait_for_http_server(httpserver)
+    return httpserver
+
+
 @pytest.fixture()
 def validating_httpserver(request):
     server = ValidatingWSGIApp()
     server.start()
+    wait_for_http_server(server)
     request.addfinalizer(server.stop)
     return server
 
@@ -140,3 +149,15 @@ def instrument():
     elasticapm.instrument()
     yield
     elasticapm.uninstrument()
+
+
+def wait_for_http_server(httpserver, timeout=30):
+    start_time = time.time()
+    while True:
+        try:
+            sock = socket.create_connection(httpserver.server_address, timeout=0.1)
+            sock.close()
+            break
+        except socket.error:
+            if time.time() - start_time > timeout:
+                raise TimeoutError()

tests/instrumentation/urllib3_tests.py

@@ -6,10 +6,10 @@
 
 
 @mock.patch("elasticapm.traces.TransactionsStore.should_collect")
-def test_urllib3(should_collect, instrument, elasticapm_client, httpserver):
+def test_urllib3(should_collect, instrument, elasticapm_client, waiting_httpserver):
     should_collect.return_value = False
-    httpserver.serve_content('')
-    url = httpserver.url + '/hello_world'
+    waiting_httpserver.serve_content('')
+    url = waiting_httpserver.url + '/hello_world'
     parsed_url = urlparse.urlparse(url)
     elasticapm_client.begin_transaction("transaction")
     expected_sig = 'GET {0}'.format(parsed_url.netloc)