4 files changed, 60 insertions, 0 deletions

diff --git a/test/cpp/interop/client.cc b/test/cpp/interop/client.cc
index 032b378b1a..999be9d8a3 100644
--- a/test/cpp/interop/client.cc
+++ b/test/cpp/interop/client.cc
@@ -149,6 +149,8 @@ int main(int argc, char** argv) {
     client.DoStatusWithMessage();
   } else if (FLAGS_test_case == "custom_metadata") {
     client.DoCustomMetadata();
+  } else if (FLAGS_test_case == "cacheable_unary") {
+    client.DoCacheableUnary();
   } else if (FLAGS_test_case == "all") {
     client.DoEmpty();
     client.DoLargeUnary();
@@ -166,6 +168,7 @@ int main(int argc, char** argv) {
     client.DoEmptyStream();
     client.DoStatusWithMessage();
     client.DoCustomMetadata();
+    client.DoCacheableUnary();
     // service_account_creds and jwt_token_creds can only run with ssl.
     if (FLAGS_use_tls) {
       grpc::string json_key = GetServiceAccountJsonKey();
@@ -177,6 +180,7 @@ int main(int argc, char** argv) {
     // compute_engine_creds only runs in GCE.
   } else {
     const char* testcases[] = {"all",
+                               "cacheable_unary",
                                "cancel_after_begin",
                                "cancel_after_first_response",
                                "client_compressed_streaming",
diff --git a/test/cpp/interop/interop_client.cc b/test/cpp/interop/interop_client.cc
index 6117878a33..e9a804ccae 100644
--- a/test/cpp/interop/interop_client.cc
+++ b/test/cpp/interop/interop_client.cc
@@ -846,6 +846,50 @@ bool InteropClient::DoStatusWithMessage() {
   return true;
 }
 
+bool InteropClient::DoCacheableUnary() {
+  gpr_log(GPR_DEBUG, "Sending RPC with cacheable response");
+
+  // Create request with current timestamp
+  gpr_timespec ts = gpr_now(GPR_CLOCK_PRECISE);
+  std::string timestamp = std::to_string((long long unsigned)ts.tv_nsec);
+  SimpleRequest request;
+  request.mutable_payload()->set_body(timestamp.c_str(), timestamp.size());
+
+  // Request 1
+  ClientContext context1;
+  SimpleResponse response1;
+  context1.set_cacheable(true);
+  // Add fake user IP since some proxy's (GFE) won't cache requests from
+  // localhost.
+  context1.AddMetadata("x-user-ip", "1.2.3.4");
+  Status s1 =
+      serviceStub_.Get()->CacheableUnaryCall(&context1, request, &response1);
+  if (!AssertStatusOk(s1)) {
+    return false;
+  }
+  gpr_log(GPR_DEBUG, "response 1 payload: %s",
+          response1.payload().body().c_str());
+
+  // Request 2
+  ClientContext context2;
+  SimpleResponse response2;
+  context2.set_cacheable(true);
+  context2.AddMetadata("x-user-ip", "1.2.3.4");
+  Status s2 =
+      serviceStub_.Get()->CacheableUnaryCall(&context2, request, &response2);
+  if (!AssertStatusOk(s2)) {
+    return false;
+  }
+  gpr_log(GPR_DEBUG, "response 2 payload: %s",
+          response2.payload().body().c_str());
+
+  // Check that the body is same for both requests. It will be the same if the
+  // second response is a cached copy of the first response
+  GPR_ASSERT(response2.payload().body() == response1.payload().body());
+
+  return true;
+}
+
 bool InteropClient::DoCustomMetadata() {
   const grpc::string kEchoInitialMetadataKey("x-grpc-test-echo-initial");
   const grpc::string kInitialMetadataValue("test_initial_metadata_value");
diff --git a/test/cpp/interop/interop_client.h b/test/cpp/interop/interop_client.h
index eb886fcb7e..1e89f0987d 100644
--- a/test/cpp/interop/interop_client.h
+++ b/test/cpp/interop/interop_client.h
@@ -79,6 +79,7 @@ class InteropClient {
   bool DoEmptyStream();
   bool DoStatusWithMessage();
   bool DoCustomMetadata();
+  bool DoCacheableUnary();
   // Auth tests.
   // username is a string containing the user email
   bool DoJwtTokenCreds(const grpc::string& username);
diff --git a/test/cpp/interop/interop_server.cc b/test/cpp/interop/interop_server.cc
index c05eb5d146..05af18bc67 100644
--- a/test/cpp/interop/interop_server.cc
+++ b/test/cpp/interop/interop_server.cc
@@ -47,6 +47,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/useful.h>
 
+#include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/byte_stream.h"
 #include "src/proto/grpc/testing/empty.grpc.pb.h"
 #include "src/proto/grpc/testing/messages.grpc.pb.h"
@@ -153,6 +154,16 @@ class TestServiceImpl : public TestService::Service {
     return Status::OK;
   }
 
+  // Response contains current timestamp. We ignore everything in the request.
+  Status CacheableUnaryCall(ServerContext* context, const SimpleRequest* request,
+                   SimpleResponse* response) {
+    gpr_timespec ts = gpr_now(GPR_CLOCK_PRECISE);
+    std::string timestamp = std::to_string((long long unsigned)ts.tv_nsec);
+    response->mutable_payload()->set_body(timestamp.c_str(), timestamp.size());
+    context->AddInitialMetadata("cache-control", "max-age=60, public");
+    return Status::OK;
+  }
+
   Status UnaryCall(ServerContext* context, const SimpleRequest* request,
                    SimpleResponse* response) {
     MaybeEchoMetadata(context);