backport to v1.13: test flake: fix flake in ApiListener integration test (envoyproxy#9808) (envoyproxy#13316)

Description: previously the test was not waiting for the expectation on the server's thread to complete. Therefore, there was a use after free race condition with the ApiListener's TlsCachingDateProvider. This PR makes it so that the test waits for the expectation to be fulfilled  and thus prevents the race.
Risk Level: low
Testing: ran integration test a few thousand times locally on a linux machine.

Signed-off-by: Jose Nino <[email protected]>
Signed-off-by: Antonio Vicente <[email protected]>

Author: antoniovicente

VERSION

@@ -1 +1 @@
-1.13.5
+1.13.6

docs/root/intro/version_history.rst

@@ -1,6 +1,12 @@
 Version history
 ---------------
 
+1.13.6 (September 29, 2020)
+===========================
+Changes
+-------
+* test: fix flaky test.
+
 1.13.5 (September 29, 2020)
 ===========================
 Changes

test/integration/api_listener_integration_test.cc

@@ -4,6 +4,7 @@
 #include "test/test_common/environment.h"
 #include "test/test_common/utility.h"
 
+#include "absl/synchronization/notification.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
@@ -76,13 +77,15 @@ name: api_listener
   NiceMock<Http::MockStreamEncoder> stream_encoder_;
 };
 
+ACTION_P(Notify, notification) { notification->Notify(); }
+
 INSTANTIATE_TEST_SUITE_P(IpVersions, ApiListenerIntegrationTest,
                          testing::ValuesIn(TestEnvironment::getIpVersionsForTest()),
                          TestUtility::ipTestParamsToString);
 
 TEST_P(ApiListenerIntegrationTest, Basic) {
-  ConditionalInitializer test_ran;
-  test_server_->server().dispatcher().post([this, &test_ran]() -> void {
+  absl::Notification done;
+  test_server_->server().dispatcher().post([this, &done]() -> void {
     ASSERT_TRUE(test_server_->server().listenerManager().apiListener().has_value());
     ASSERT_EQ("api_listener", test_server_->server().listenerManager().apiListener()->get().name());
     ASSERT_TRUE(test_server_->server().listenerManager().apiListener()->get().http().has_value());
@@ -97,17 +100,15 @@ TEST_P(ApiListenerIntegrationTest, Basic) {
     Http::TestHeaderMapImpl expected_response_headers{{":status", "200"}};
     EXPECT_CALL(stream_encoder_, encodeHeaders(_, false));
     EXPECT_CALL(stream_encoder_, encodeData(_, false));
-    EXPECT_CALL(stream_encoder_, encodeData(BufferStringEqual(""), true));
+    EXPECT_CALL(stream_encoder_, encodeData(BufferStringEqual(""), true)).WillOnce(Notify(&done));
 
     // Send a headers-only request
     stream_decoder.decodeHeaders(
         Http::HeaderMapPtr(new Http::TestHeaderMapImpl{
             {":method", "GET"}, {":path", "/api"}, {":scheme", "http"}, {":authority", "host"}}),
         true);
-
-    test_ran.setReady();
   });
-  test_ran.waitReady();
+  ASSERT_TRUE(done.WaitForNotificationWithTimeout(absl::Seconds(1)));
 }
 
 } // namespace