make the failover timeout a constructor argument of ConnectionGrid

source/common/http/conn_pool_grid.cc

@@ -70,8 +70,7 @@ void ConnectivityGrid::WrapperCallbacks::newStream() {
   auto attempt = std::make_unique<ConnectionAttemptCallbacks>(*this, current_);
   LinkedList::moveIntoList(std::move(attempt), connection_attempts_);
   if (!next_attempt_timer_->enabled()) {
-    // TODO(#15649) When adding config for the grid, make this configurable.
-    next_attempt_timer_->enableTimer(std::chrono::milliseconds(300));
+    next_attempt_timer_->enableTimer(grid_.next_attempt_duration_);
   }
 }
 
@@ -117,10 +116,10 @@ ConnectivityGrid::ConnectivityGrid(
     const Network::ConnectionSocket::OptionsSharedPtr& options,
     const Network::TransportSocketOptionsSharedPtr& transport_socket_options,
     Upstream::ClusterConnectivityState& state, TimeSource& time_source,
-    ConnectivityOptions connectivity_options)
+    std::chrono::milliseconds next_attempt_duration, ConnectivityOptions connectivity_options)
     : dispatcher_(dispatcher), random_generator_(random_generator), host_(host),
       priority_(priority), options_(options), transport_socket_options_(transport_socket_options),
-      state_(state), time_source_(time_source) {
+      state_(state), next_attempt_duration_(next_attempt_duration), time_source_(time_source) {
   // TODO(#15649) support v6/v4, WiFi/cellular.
   ASSERT(connectivity_options.protocols_.size() == 3);
   ASSERT(contains(connectivity_options.protocols_,

source/common/http/conn_pool_grid.h

@@ -95,6 +95,7 @@ class ConnectivityGrid : public ConnectionPool::Instance,
                    const Network::ConnectionSocket::OptionsSharedPtr& options,
                    const Network::TransportSocketOptionsSharedPtr& transport_socket_options,
                    Upstream::ClusterConnectivityState& state, TimeSource& time_source,
+                   std::chrono::milliseconds next_attempt_duration,
                    ConnectivityOptions connectivity_options);
   ~ConnectivityGrid() override;
 
@@ -130,6 +131,7 @@ class ConnectivityGrid : public ConnectionPool::Instance,
   const Network::ConnectionSocket::OptionsSharedPtr& options_;
   const Network::TransportSocketOptionsSharedPtr& transport_socket_options_;
   Upstream::ClusterConnectivityState& state_;
+  std::chrono::milliseconds next_attempt_duration_;
   TimeSource& time_source_;
 
   // Tracks how many drains are needed before calling drain callbacks. This is

test/common/http/conn_pool_grid_test.cc

@@ -20,6 +20,7 @@ using Envoy::Event::MockTimer;
 using testing::_;
 using testing::AnyNumber;
 using testing::Return;
+using testing::StrictMock;
 
 namespace Envoy {
 namespace Http {
@@ -87,7 +88,7 @@ class ConnectivityGridTest : public Event::TestUsingSimulatedTime, public testin
         grid_(dispatcher_, random_,
               Upstream::makeTestHost(cluster_, "hostname", "tcp://127.0.0.1:9000", simTime()),
               Upstream::ResourcePriority::Default, socket_options_, transport_socket_options_,
-              state_, simTime(), options_) {}
+              state_, simTime(), std::chrono::milliseconds(300), options_) {}
 
   const Network::ConnectionSocket::OptionsSharedPtr socket_options_;
   const Network::TransportSocketOptionsSharedPtr transport_socket_options_;
@@ -152,7 +153,9 @@ TEST_F(ConnectivityGridTest, TimeoutThenSuccessParallelSecondConnects) {
   EXPECT_EQ(grid_.first(), nullptr);
 
   // This timer will be returned and armed as the grid creates the wrapper's failover timer.
-  Event::MockTimer* failover_timer = new NiceMock<MockTimer>(&dispatcher_);
+  Event::MockTimer* failover_timer = new StrictMock<MockTimer>(&dispatcher_);
+  EXPECT_CALL(*failover_timer, enableTimer(std::chrono::milliseconds(300), nullptr)).Times(2);
+  EXPECT_CALL(*failover_timer, enabled()).WillRepeatedly(Return(false));
 
   grid_.newStream(decoder_, callbacks_);
   EXPECT_NE(grid_.first(), nullptr);