enable retry proxy tests (#26425)

* Use trailers_only info to guide proxy

* Mark 1 test still unproxyable

* enable retry_too_many_attempts proxy test

* disable retries in proxy

* clang-format

Co-authored-by: Vijay Pai <vpai@google.com>

test/core/end2end/fixtures/proxy.cc

@@ -28,6 +28,7 @@
 #include "src/core/lib/gprpp/host_port.h"
 #include "src/core/lib/gprpp/memory.h"
 #include "src/core/lib/gprpp/thd.h"
+#include "src/core/lib/surface/call.h"
 #include "test/core/util/port.h"
 
 struct grpc_end2end_proxy {
@@ -99,7 +100,16 @@ grpc_end2end_proxy* grpc_end2end_proxy_create(const grpc_end2end_proxy_def* def,
 
   proxy->cq = grpc_completion_queue_create_for_next(nullptr);
   proxy->server = def->create_server(proxy->proxy_port.c_str(), server_args);
-  proxy->client = def->create_client(proxy->server_port.c_str(), client_args);
+
+  const char* arg_to_remove = GRPC_ARG_ENABLE_RETRIES;
+  grpc_arg arg_to_add = grpc_channel_arg_integer_create(
+      const_cast<char*>(GRPC_ARG_ENABLE_RETRIES), 0);
+  grpc_channel_args* proxy_client_args =
+      grpc_channel_args_copy_and_add_and_remove(client_args, &arg_to_remove, 1,
+                                                &arg_to_add, 1);
+  proxy->client =
+      def->create_client(proxy->server_port.c_str(), proxy_client_args);
+  grpc_channel_args_destroy(proxy_client_args);
 
   grpc_server_register_completion_queue(proxy->server, proxy->cq, nullptr);
   grpc_server_start(proxy->server);
@@ -164,7 +174,7 @@ static void on_p2s_recv_initial_metadata(void* arg, int /*success*/) {
   grpc_call_error err;
 
   memset(&op, 0, sizeof(op));
-  if (!pc->proxy->shutdown) {
+  if (!pc->proxy->shutdown && !grpc_call_is_trailers_only(pc->p2s)) {
     op.op = GRPC_OP_SEND_INITIAL_METADATA;
     op.flags = 0;
     op.reserved = nullptr;
@@ -294,22 +304,33 @@ static void on_c2p_sent_status(void* arg, int /*success*/) {
 
 static void on_p2s_status(void* arg, int success) {
   proxy_call* pc = static_cast<proxy_call*>(arg);
-  grpc_op op;
+  grpc_op op[2];  // Possibly send empty initial metadata also if trailers-only
   grpc_call_error err;
 
+  memset(op, 0, sizeof(op));
+
   if (!pc->proxy->shutdown) {
     GPR_ASSERT(success);
-    op.op = GRPC_OP_SEND_STATUS_FROM_SERVER;
-    op.flags = 0;
-    op.reserved = nullptr;
-    op.data.send_status_from_server.trailing_metadata_count =
+
+    int op_count = 0;
+    if (grpc_call_is_trailers_only(pc->p2s)) {
+      op[op_count].op = GRPC_OP_SEND_INITIAL_METADATA;
+      op_count++;
+    }
+
+    op[op_count].op = GRPC_OP_SEND_STATUS_FROM_SERVER;
+    op[op_count].flags = 0;
+    op[op_count].reserved = nullptr;
+    op[op_count].data.send_status_from_server.trailing_metadata_count =
         pc->p2s_trailing_metadata.count;
-    op.data.send_status_from_server.trailing_metadata =
+    op[op_count].data.send_status_from_server.trailing_metadata =
         pc->p2s_trailing_metadata.metadata;
-    op.data.send_status_from_server.status = pc->p2s_status;
-    op.data.send_status_from_server.status_details = &pc->p2s_status_details;
+    op[op_count].data.send_status_from_server.status = pc->p2s_status;
+    op[op_count].data.send_status_from_server.status_details =
+        &pc->p2s_status_details;
+    op_count++;
     refpc(pc, "on_c2p_sent_status");
-    err = grpc_call_start_batch(pc->c2p, &op, 1,
+    err = grpc_call_start_batch(pc->c2p, op, op_count,
                                 new_closure(on_c2p_sent_status, pc), nullptr);
     GPR_ASSERT(err == GRPC_CALL_OK);
   }

test/core/end2end/generate_tests.bzl

@@ -272,89 +272,47 @@ END2END_TESTS = {
     "registered_call": _test_options(),
     "request_with_flags": _test_options(proxyable = False),
     "request_with_payload": _test_options(),
-    # TODO(roth): Remove proxyable=False for all retry tests once we
-    # have a way for the proxy to propagate the fact that trailing
-    # metadata is available when initial metadata is returned.
-    # See https://github.com/grpc/grpc/issues/14467 for context.
-    "retry": _test_options(needs_client_channel = True, proxyable = False),
-    "retry_cancellation": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_cancel_during_delay": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_disabled": _test_options(needs_client_channel = True, proxyable = False),
+    "retry": _test_options(needs_client_channel = True),
+    "retry_cancellation": _test_options(needs_client_channel = True),
+    "retry_cancel_during_delay": _test_options(needs_client_channel = True),
+    "retry_disabled": _test_options(needs_client_channel = True),
     "retry_exceeds_buffer_size_in_delay": _test_options(
         needs_client_channel = True,
-        proxyable = False,
     ),
     "retry_exceeds_buffer_size_in_initial_batch": _test_options(
         needs_client_channel = True,
-        proxyable = False,
         # TODO(jtattermusch): too long bazel test name makes the test flaky on Windows RBE
         # See b/151617965
         short_name = "retry_exceeds_buffer_size_in_init",
     ),
     "retry_exceeds_buffer_size_in_subsequent_batch": _test_options(
         needs_client_channel = True,
-        proxyable = False,
         # TODO(jtattermusch): too long bazel test name makes the test flaky on Windows RBE
         # See b/151617965
         short_name = "retry_exceeds_buffer_size_in_subseq",
     ),
-    "retry_lb_drop": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_non_retriable_status": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
+    "retry_lb_drop": _test_options(needs_client_channel = True),
+    "retry_non_retriable_status": _test_options(needs_client_channel = True),
     "retry_non_retriable_status_before_recv_trailing_metadata_started": _test_options(
         needs_client_channel = True,
-        proxyable = False,
         # TODO(jtattermusch): too long bazel test name makes the test flaky on Windows RBE
         # See b/151617965
         short_name = "retry_non_retriable_status2",
     ),
-    "retry_recv_initial_metadata": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_recv_message": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_server_pushback_delay": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_server_pushback_disabled": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_streaming": _test_options(needs_client_channel = True, proxyable = False),
-    "retry_streaming_after_commit": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
+    "retry_recv_initial_metadata": _test_options(needs_client_channel = True),
+    "retry_recv_message": _test_options(needs_client_channel = True),
+    "retry_server_pushback_delay": _test_options(needs_client_channel = True),
+    "retry_server_pushback_disabled": _test_options(needs_client_channel = True),
+    "retry_streaming": _test_options(needs_client_channel = True),
+    "retry_streaming_after_commit": _test_options(needs_client_channel = True),
     "retry_streaming_succeeds_before_replay_finished": _test_options(
         needs_client_channel = True,
-        proxyable = False,
         # TODO(jtattermusch): too long bazel test name makes the test flaky on Windows RBE
         # See b/151617965
         short_name = "retry_streaming2",
     ),
-    "retry_throttled": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
-    "retry_too_many_attempts": _test_options(
-        needs_client_channel = True,
-        proxyable = False,
-    ),
+    "retry_throttled": _test_options(needs_client_channel = True),
+    "retry_too_many_attempts": _test_options(needs_client_channel = True),
     "server_finishes_request": _test_options(),
     "server_streaming": _test_options(needs_http2 = True),
     "shutdown_finishes_calls": _test_options(),