Merge pull request #7735 from y-zeng/cli_main_fork

Improve gRPC CLI

10 files changed, 1048 insertions, 261 deletions

diff --git a/test/cpp/util/cli_credentials.cc b/test/cpp/util/cli_credentials.cc
new file mode 100644
index 0000000000..8de9393e4d
--- /dev/null
+++ b/test/cpp/util/cli_credentials.cc
@@ -0,0 +1,63 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "test/cpp/util/cli_credentials.h"
+
+#include <gflags/gflags.h>
+
+DEFINE_bool(enable_ssl, false, "Whether to use ssl/tls.");
+DEFINE_bool(use_auth, false, "Whether to create default google credentials.");
+
+namespace grpc {
+namespace testing {
+
+std::shared_ptr<grpc::ChannelCredentials> CliCredentials::GetCredentials()
+    const {
+  if (!FLAGS_enable_ssl) {
+    return grpc::InsecureChannelCredentials();
+  } else {
+    if (FLAGS_use_auth) {
+      return grpc::GoogleDefaultCredentials();
+    } else {
+      return grpc::SslCredentials(grpc::SslCredentialsOptions());
+    }
+  }
+}
+
+const grpc::string CliCredentials::GetCredentialUsage() const {
+  return "    --enable_ssl             ; Set whether to use tls\n"
+         "    --use_auth               ; Set whether to create default google"
+         " credentials\n";
+}
+}  // namespace testing
+}  // namespace grpc
diff --git a/test/cpp/util/cli_credentials.h b/test/cpp/util/cli_credentials.h
new file mode 100644
index 0000000000..581b77a9c6
--- /dev/null
+++ b/test/cpp/util/cli_credentials.h
@@ -0,0 +1,53 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_TEST_CPP_UTIL_CLI_CREDENTIALS_H
+#define GRPC_TEST_CPP_UTIL_CLI_CREDENTIALS_H
+
+#include <grpc++/security/credentials.h>
+#include <grpc++/support/config.h>
+
+namespace grpc {
+namespace testing {
+
+class CliCredentials {
+ public:
+  virtual ~CliCredentials() {}
+  virtual std::shared_ptr<grpc::ChannelCredentials> GetCredentials() const;
+  virtual const grpc::string GetCredentialUsage() const;
+};
+
+}  // namespace testing
+}  // namespace grpc
+
+#endif  // GRPC_TEST_CPP_UTIL_CLI_CREDENTIALS_H
diff --git a/test/cpp/util/config_grpc_cli.h b/test/cpp/util/config_grpc_cli.h
new file mode 100644
index 0000000000..ea8231aa26
--- /dev/null
+++ b/test/cpp/util/config_grpc_cli.h
@@ -0,0 +1,85 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_TEST_CPP_UTIL_CONFIG_GRPC_CLI_H
+#define GRPC_TEST_CPP_UTIL_CONFIG_GRPC_CLI_H
+
+#include <grpc++/impl/codegen/config_protobuf.h>
+
+#ifndef GRPC_CUSTOM_DYNAMICMESSAGEFACTORY
+#include <google/protobuf/dynamic_message.h>
+#define GRPC_CUSTOM_DYNAMICMESSAGEFACTORY \
+  ::google::protobuf::DynamicMessageFactory
+#endif
+
+#ifndef GRPC_CUSTOM_DESCRIPTORPOOLDATABASE
+#include <google/protobuf/descriptor.h>
+#define GRPC_CUSTOM_DESCRIPTORPOOLDATABASE \
+  ::google::protobuf::DescriptorPoolDatabase
+#define GRPC_CUSTOM_MERGEDDESCRIPTORDATABASE \
+  ::google::protobuf::MergedDescriptorDatabase
+#endif
+
+#ifndef GRPC_CUSTOM_TEXTFORMAT
+#include <google/protobuf/text_format.h>
+#define GRPC_CUSTOM_TEXTFORMAT ::google::protobuf::TextFormat
+#endif
+
+#ifndef GRPC_CUSTOM_DISKSOURCETREE
+#include <google/protobuf/compiler/importer.h>
+#define GRPC_CUSTOM_DISKSOURCETREE ::google::protobuf::compiler::DiskSourceTree
+#define GRPC_CUSTOM_IMPORTER ::google::protobuf::compiler::Importer
+#define GRPC_CUSTOM_MULTIFILEERRORCOLLECTOR \
+  ::google::protobuf::compiler::MultiFileErrorCollector
+#endif
+
+namespace grpc {
+namespace protobuf {
+
+typedef GRPC_CUSTOM_DYNAMICMESSAGEFACTORY DynamicMessageFactory;
+
+typedef GRPC_CUSTOM_DESCRIPTORPOOLDATABASE DescriptorPoolDatabase;
+typedef GRPC_CUSTOM_MERGEDDESCRIPTORDATABASE MergedDescriptorDatabase;
+
+typedef GRPC_CUSTOM_TEXTFORMAT TextFormat;
+
+namespace compiler {
+typedef GRPC_CUSTOM_DISKSOURCETREE DiskSourceTree;
+typedef GRPC_CUSTOM_IMPORTER Importer;
+typedef GRPC_CUSTOM_MULTIFILEERRORCOLLECTOR MultiFileErrorCollector;
+}  // namespace importer
+
+}  // namespace protobuf
+}  // namespace grpc
+
+#endif  // GRPC_TEST_CPP_UTIL_CONFIG_GRPC_CLI_H
diff --git a/test/cpp/util/grpc_cli.cc b/test/cpp/util/grpc_cli.cc
index 53529da782..fe248601ee 100644
--- a/test/cpp/util/grpc_cli.cc
+++ b/test/cpp/util/grpc_cli.cc
@@ -33,12 +33,14 @@
 
 /*
   A command line tool to talk to a grpc server.
+  Run `grpc_cli help` command to see its usage information.
+
   Example of talking to grpc interop server:
   grpc_cli call localhost:50051 UnaryCall "response_size:10" \
       --protofiles=src/proto/grpc/testing/test.proto --enable_ssl=false
 
   Options:
-    1. --protofiles, use this flag to provide a proto file if the server does
+    1. --protofiles, use this flag to provide proto files if the server does
        does not have the reflection service.
     2. --proto_path, if your proto file is not under current working directory,
        use this flag to provide a search root. It should work similar to the
@@ -48,15 +50,17 @@
        --metadata="MyHeaderKey1:Value1:MyHeaderKey2:Value2"
     4. --enable_ssl, whether to use tls.
     5. --use_auth, if set to true, attach a GoogleDefaultCredentials to the call
-    6. --input_binary_file, a file containing the serialized request. The file
-       can be generated by calling something like:
+    6. --infile, input filename (defaults to stdin)
+    7. --outfile, output filename (defaults to stdout)
+    8. --binary_input, use the serialized request as input. The serialized
+       request can be generated by calling something like:
        protoc --proto_path=src/proto/grpc/testing/ \
          --encode=grpc.testing.SimpleRequest \
          src/proto/grpc/testing/messages.proto \
          < input.txt > input.bin
        If this is used and no proto file is provided in the argument list, the
        method string has to be exact in the form of /package.service/method.
-    7. --output_binary_file, a file to write binary format response into, it can
+    9. --binary_output, use binary format response as output, it can
        be later decoded using protoc:
        protoc --proto_path=src/proto/grpc/testing/ \
        --decode=grpc.testing.SimpleResponse \
@@ -64,182 +68,34 @@
        < output.bin > output.txt
 */
 
-#include <unistd.h>
 #include <fstream>
+#include <functional>
 #include <iostream>
-#include <sstream>
 
 #include <gflags/gflags.h>
-#include <grpc++/channel.h>
-#include <grpc++/create_channel.h>
-#include <grpc++/security/credentials.h>
-#include <grpc++/support/string_ref.h>
-#include <grpc/grpc.h>
-
-#include "test/cpp/util/cli_call.h"
-#include "test/cpp/util/proto_file_parser.h"
-#include "test/cpp/util/string_ref_helper.h"
+#include <grpc++/support/config.h>
+#include "test/cpp/util/cli_credentials.h"
+#include "test/cpp/util/grpc_tool.h"
 #include "test/cpp/util/test_config.h"
 
-DEFINE_bool(enable_ssl, true, "Whether to use ssl/tls.");
-DEFINE_bool(use_auth, false, "Whether to create default google credentials.");
-DEFINE_string(input_binary_file, "",
-              "Path to input file containing serialized request.");
-DEFINE_string(output_binary_file, "",
-              "Path to output file to write serialized response.");
-DEFINE_string(metadata, "",
-              "Metadata to send to server, in the form of key1:val1:key2:val2");
-DEFINE_string(proto_path, ".", "Path to look for the proto file.");
-// TODO(zyc): support a list of input proto files
-DEFINE_string(protofiles, "", "Name of the proto file.");
-
-void ParseMetadataFlag(
-    std::multimap<grpc::string, grpc::string>* client_metadata) {
-  if (FLAGS_metadata.empty()) {
-    return;
-  }
-  std::vector<grpc::string> fields;
-  const char* delim = ":";
-  size_t cur, next = -1;
-  do {
-    cur = next + 1;
-    next = FLAGS_metadata.find_first_of(delim, cur);
-    fields.push_back(FLAGS_metadata.substr(cur, next - cur));
-  } while (next != grpc::string::npos);
-  if (fields.size() % 2) {
-    std::cout << "Failed to parse metadata flag" << std::endl;
-    exit(1);
-  }
-  for (size_t i = 0; i < fields.size(); i += 2) {
-    client_metadata->insert(
-        std::pair<grpc::string, grpc::string>(fields[i], fields[i + 1]));
-  }
-}
+DEFINE_string(outfile, "", "Output file (default is stdout)");
 
-template <typename T>
-void PrintMetadata(const T& m, const grpc::string& message) {
-  if (m.empty()) {
-    return;
-  }
-  std::cout << message << std::endl;
-  grpc::string pair;
-  for (typename T::const_iterator iter = m.begin(); iter != m.end(); ++iter) {
-    pair.clear();
-    pair.append(iter->first.data(), iter->first.size());
-    pair.append(" : ");
-    pair.append(iter->second.data(), iter->second.size());
-    std::cout << pair << std::endl;
+static bool SimplePrint(const grpc::string& outfile,
+                        const grpc::string& output) {
+  if (outfile.empty()) {
+    std::cout << output;
+  } else {
+    std::ofstream output_file(outfile, std::ios::trunc | std::ios::binary);
+    output_file << output;
+    output_file.close();
   }
+  return true;
 }
 
 int main(int argc, char** argv) {
   grpc::testing::InitTest(&argc, &argv, true);
 
-  if (argc < 4 || grpc::string(argv[1]) != "call") {
-    std::cout << "Usage: grpc_cli call server_host:port method_name "
-              << "[proto file] [text format request] [<options>]" << std::endl;
-    return 1;
-  }
-
-  grpc::string request_text;
-  grpc::string server_address(argv[2]);
-  grpc::string method_name(argv[3]);
-  std::unique_ptr<grpc::testing::ProtoFileParser> parser;
-  grpc::string serialized_request_proto;
-
-  if (argc == 5) {
-    request_text = argv[4];
-  }
-
-  std::shared_ptr<grpc::ChannelCredentials> creds;
-  if (!FLAGS_enable_ssl) {
-    creds = grpc::InsecureChannelCredentials();
-  } else {
-    if (FLAGS_use_auth) {
-      creds = grpc::GoogleDefaultCredentials();
-    } else {
-      creds = grpc::SslCredentials(grpc::SslCredentialsOptions());
-    }
-  }
-  std::shared_ptr<grpc::Channel> channel =
-      grpc::CreateChannel(server_address, creds);
-
-  if (request_text.empty() && FLAGS_input_binary_file.empty()) {
-    if (isatty(STDIN_FILENO)) {
-      std::cout << "reading request message from stdin..." << std::endl;
-    }
-    std::stringstream input_stream;
-    input_stream << std::cin.rdbuf();
-    request_text = input_stream.str();
-  }
-
-  if (!request_text.empty()) {
-    if (!FLAGS_protofiles.empty()) {
-      parser.reset(new grpc::testing::ProtoFileParser(
-          FLAGS_proto_path, FLAGS_protofiles, method_name));
-    } else {
-      parser.reset(new grpc::testing::ProtoFileParser(channel, method_name));
-    }
-    method_name = parser->GetFullMethodName();
-    if (parser->HasError()) {
-      return 1;
-    }
-
-    if (!FLAGS_input_binary_file.empty()) {
-      std::cout
-          << "warning: request given in argv, ignoring --input_binary_file"
-          << std::endl;
-    }
-  }
-
-  if (parser) {
-    serialized_request_proto =
-        parser->GetSerializedProto(request_text, true /* is_request */);
-    if (parser->HasError()) {
-      return 1;
-    }
-  } else if (!FLAGS_input_binary_file.empty()) {
-    std::ifstream input_file(FLAGS_input_binary_file,
-                             std::ios::in | std::ios::binary);
-    std::stringstream input_stream;
-    input_stream << input_file.rdbuf();
-    serialized_request_proto = input_stream.str();
-  }
-  std::cout << "connecting to " << server_address << std::endl;
-
-  grpc::string serialized_response_proto;
-  std::multimap<grpc::string, grpc::string> client_metadata;
-  std::multimap<grpc::string_ref, grpc::string_ref> server_initial_metadata,
-      server_trailing_metadata;
-  ParseMetadataFlag(&client_metadata);
-  PrintMetadata(client_metadata, "Sending client initial metadata:");
-  grpc::Status s = grpc::testing::CliCall::Call(
-      channel, method_name, serialized_request_proto,
-      &serialized_response_proto, client_metadata, &server_initial_metadata,
-      &server_trailing_metadata);
-  PrintMetadata(server_initial_metadata,
-                "Received initial metadata from server:");
-  PrintMetadata(server_trailing_metadata,
-                "Received trailing metadata from server:");
-  if (s.ok()) {
-    std::cout << "Rpc succeeded with OK status" << std::endl;
-    if (parser) {
-      grpc::string response_text = parser->GetTextFormat(
-          serialized_response_proto, false /* is_request */);
-      if (parser->HasError()) {
-        return 1;
-      }
-      std::cout << "Response: \n " << response_text << std::endl;
-    }
-    if (!FLAGS_output_binary_file.empty()) {
-      std::ofstream output_file(FLAGS_output_binary_file,
-                                std::ios::trunc | std::ios::binary);
-      output_file << serialized_response_proto;
-    }
-  } else {
-    std::cout << "Rpc failed with status code " << s.error_code()
-              << ", error message: " << s.error_message() << std::endl;
-  }
-
-  return 0;
+  return grpc::testing::GrpcToolMainLib(
+      argc, (const char**)argv, grpc::testing::CliCredentials(),
+      std::bind(SimplePrint, FLAGS_outfile, std::placeholders::_1));
 }
diff --git a/test/cpp/util/grpc_tool.cc b/test/cpp/util/grpc_tool.cc
new file mode 100644
index 0000000000..f06053ca23
--- /dev/null
+++ b/test/cpp/util/grpc_tool.cc
@@ -0,0 +1,365 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "test/cpp/util/grpc_tool.h"
+
+#include <unistd.h>
+#include <fstream>
+#include <iostream>
+#include <memory>
+#include <sstream>
+#include <string>
+
+#include <gflags/gflags.h>
+#include <grpc++/channel.h>
+#include <grpc++/create_channel.h>
+#include <grpc++/grpc++.h>
+#include <grpc++/security/credentials.h>
+#include <grpc++/support/string_ref.h>
+#include <grpc/grpc.h>
+
+#include "test/cpp/util/cli_call.h"
+#include "test/cpp/util/proto_file_parser.h"
+#include "test/cpp/util/proto_reflection_descriptor_database.h"
+#include "test/cpp/util/test_config.h"
+
+DEFINE_bool(remotedb, true, "Use server types to parse and format messages");
+DEFINE_string(metadata, "",
+              "Metadata to send to server, in the form of key1:val1:key2:val2");
+DEFINE_string(proto_path, ".", "Path to look for the proto file.");
+DEFINE_string(proto_file, "", "Name of the proto file.");
+DEFINE_bool(binary_input, false, "Input in binary format");
+DEFINE_bool(binary_output, false, "Output in binary format");
+DEFINE_string(infile, "", "Input file (default is stdin)");
+
+namespace grpc {
+namespace testing {
+namespace {
+
+class GrpcTool {
+ public:
+  explicit GrpcTool();
+  virtual ~GrpcTool() {}
+
+  bool Help(int argc, const char** argv, CliCredentials cred,
+            GrpcToolOutputCallback callback);
+  bool CallMethod(int argc, const char** argv, CliCredentials cred,
+                  GrpcToolOutputCallback callback);
+  // TODO(zyc): implement the following methods
+  // bool ListServices(int argc, const char** argv, GrpcToolOutputCallback
+  // callback);
+  // bool PrintType(int argc, const char** argv, GrpcToolOutputCallback
+  // callback);
+  // bool PrintTypeId(int argc, const char** argv, GrpcToolOutputCallback
+  // callback);
+  // bool ParseMessage(int argc, const char** argv, GrpcToolOutputCallback
+  // callback);
+  // bool ToText(int argc, const char** argv, GrpcToolOutputCallback callback);
+  // bool ToBinary(int argc, const char** argv, GrpcToolOutputCallback
+  // callback);
+
+  void SetPrintCommandMode(int exit_status) {
+    print_command_usage_ = true;
+    usage_exit_status_ = exit_status;
+  }
+
+ private:
+  void CommandUsage(const grpc::string& usage) const;
+  bool print_command_usage_;
+  int usage_exit_status_;
+  const grpc::string cred_usage_;
+};
+
+template <typename T>
+std::function<bool(GrpcTool*, int, const char**, const CliCredentials,
+                   GrpcToolOutputCallback)>
+BindWith5Args(T&& func) {
+  return std::bind(std::forward<T>(func), std::placeholders::_1,
+                   std::placeholders::_2, std::placeholders::_3,
+                   std::placeholders::_4, std::placeholders::_5);
+}
+
+template <typename T>
+size_t ArraySize(T& a) {
+  return ((sizeof(a) / sizeof(*(a))) /
+          static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))));
+}
+
+void ParseMetadataFlag(
+    std::multimap<grpc::string, grpc::string>* client_metadata) {
+  if (FLAGS_metadata.empty()) {
+    return;
+  }
+  std::vector<grpc::string> fields;
+  const char* delim = ":";
+  size_t cur, next = -1;
+  do {
+    cur = next + 1;
+    next = FLAGS_metadata.find_first_of(delim, cur);
+    fields.push_back(FLAGS_metadata.substr(cur, next - cur));
+  } while (next != grpc::string::npos);
+  if (fields.size() % 2) {
+    fprintf(stderr, "Failed to parse metadata flag.\n");
+    exit(1);
+  }
+  for (size_t i = 0; i < fields.size(); i += 2) {
+    client_metadata->insert(
+        std::pair<grpc::string, grpc::string>(fields[i], fields[i + 1]));
+  }
+}
+
+template <typename T>
+void PrintMetadata(const T& m, const grpc::string& message) {
+  if (m.empty()) {
+    return;
+  }
+  fprintf(stderr, "%s\n", message.c_str());
+  grpc::string pair;
+  for (typename T::const_iterator iter = m.begin(); iter != m.end(); ++iter) {
+    pair.clear();
+    pair.append(iter->first.data(), iter->first.size());
+    pair.append(" : ");
+    pair.append(iter->second.data(), iter->second.size());
+    fprintf(stderr, "%s\n", pair.c_str());
+  }
+}
+
+struct Command {
+  const char* command;
+  std::function<bool(GrpcTool*, int, const char**, const CliCredentials,
+                     GrpcToolOutputCallback)>
+      function;
+  int min_args;
+  int max_args;
+};
+
+const Command ops[] = {
+    {"help", BindWith5Args(&GrpcTool::Help), 0, INT_MAX},
+    // {"ls", BindWith5Args(&GrpcTool::ListServices), 1, 3},
+    // {"list", BindWith5Args(&GrpcTool::ListServices), 1, 3},
+    {"call", BindWith5Args(&GrpcTool::CallMethod), 2, 3},
+    // {"type", BindWith5Args(&GrpcTool::PrintType), 2, 2},
+    // {"parse", BindWith5Args(&GrpcTool::ParseMessage), 2, 3},
+    // {"totext", BindWith5Args(&GrpcTool::ToText), 2, 3},
+    // {"tobinary", BindWith5Args(&GrpcTool::ToBinary), 2, 3},
+};
+
+void Usage(const grpc::string& msg) {
+  fprintf(
+      stderr,
+      "%s\n"
+      // "  grpc_cli ls ...         ; List services\n"
+      "  grpc_cli call ...       ; Call method\n"
+      // "  grpc_cli type ...       ; Print type\n"
+      // "  grpc_cli parse ...      ; Parse message\n"
+      // "  grpc_cli totext ...     ; Convert binary message to text\n"
+      // "  grpc_cli tobinary ...   ; Convert text message to binary\n"
+      "  grpc_cli help ...       ; Print this message, or per-command usage\n"
+      "\n",
+      msg.c_str());
+
+  exit(1);
+}
+
+const Command* FindCommand(const grpc::string& name) {
+  for (int i = 0; i < (int)ArraySize(ops); i++) {
+    if (name == ops[i].command) {
+      return &ops[i];
+    }
+  }
+  return NULL;
+}
+}  // namespace
+
+int GrpcToolMainLib(int argc, const char** argv, const CliCredentials cred,
+                    GrpcToolOutputCallback callback) {
+  if (argc < 2) {
+    Usage("No command specified");
+  }
+
+  grpc::string command = argv[1];
+  argc -= 2;
+  argv += 2;
+
+  const Command* cmd = FindCommand(command);
+  if (cmd != NULL) {
+    GrpcTool grpc_tool;
+    if (argc < cmd->min_args || argc > cmd->max_args) {
+      // Force the command to print its usage message
+      fprintf(stderr, "\nWrong number of arguments for %s\n", command.c_str());
+      grpc_tool.SetPrintCommandMode(1);
+      return cmd->function(&grpc_tool, -1, NULL, cred, callback);
+    }
+    const bool ok = cmd->function(&grpc_tool, argc, argv, cred, callback);
+    return ok ? 0 : 1;
+  } else {
+    Usage("Invalid command '" + grpc::string(command.c_str()) + "'");
+  }
+  return 1;
+}
+
+GrpcTool::GrpcTool() : print_command_usage_(false), usage_exit_status_(0) {}
+
+void GrpcTool::CommandUsage(const grpc::string& usage) const {
+  if (print_command_usage_) {
+    fprintf(stderr, "\n%s%s\n", usage.c_str(),
+            (usage.empty() || usage[usage.size() - 1] != '\n') ? "\n" : "");
+    exit(usage_exit_status_);
+  }
+}
+
+bool GrpcTool::Help(int argc, const char** argv, const CliCredentials cred,
+                    GrpcToolOutputCallback callback) {
+  CommandUsage(
+      "Print help\n"
+      "  grpc_cli help [subcommand]\n");
+
+  if (argc == 0) {
+    Usage("");
+  } else {
+    const Command* cmd = FindCommand(argv[0]);
+    if (cmd == NULL) {
+      Usage("Unknown command '" + grpc::string(argv[0]) + "'");
+    }
+    SetPrintCommandMode(0);
+    cmd->function(this, -1, NULL, cred, callback);
+  }
+  return true;
+}
+
+bool GrpcTool::CallMethod(int argc, const char** argv,
+                          const CliCredentials cred,
+                          GrpcToolOutputCallback callback) {
+  CommandUsage(
+      "Call method\n"
+      "  grpc_cli call <address> <service>[.<method>] <request>\n"
+      "    <address>                ; host:port\n"
+      "    <service>                ; Exported service name\n"
+      "    <method>                 ; Method name\n"
+      "    <request>                ; Text protobuffer (overrides infile)\n"
+      "    --proto_file             ; Comma separated proto files used as a"
+      " fallback when parsing request/response\n"
+      "    --proto_path             ; The search path of proto files, valid"
+      " only when --proto_file is given\n"
+      "    --metadata               ; The metadata to be sent to the server\n"
+      "    --infile                 ; Input filename (defaults to stdin)\n"
+      "    --outfile                ; Output filename (defaults to stdout)\n"
+      "    --binary_input           ; Input in binary format\n"
+      "    --binary_output          ; Output in binary format\n" +
+      cred.GetCredentialUsage());
+
+  std::stringstream output_ss;
+  grpc::string request_text;
+  grpc::string server_address(argv[0]);
+  grpc::string method_name(argv[1]);
+  std::unique_ptr<grpc::testing::ProtoFileParser> parser;
+  grpc::string serialized_request_proto;
+
+  if (argc == 3) {
+    request_text = argv[2];
+    if (!FLAGS_infile.empty()) {
+      fprintf(stderr, "warning: request given in argv, ignoring --infile\n");
+    }
+  } else {
+    std::stringstream input_stream;
+    if (FLAGS_infile.empty()) {
+      if (isatty(STDIN_FILENO)) {
+        fprintf(stderr, "reading request message from stdin...\n");
+      }
+      input_stream << std::cin.rdbuf();
+    } else {
+      std::ifstream input_file(FLAGS_infile, std::ios::in | std::ios::binary);
+      input_stream << input_file.rdbuf();
+      input_file.close();
+    }
+    request_text = input_stream.str();
+  }
+
+  std::shared_ptr<grpc::Channel> channel =
+      grpc::CreateChannel(server_address, cred.GetCredentials());
+  if (!FLAGS_binary_input || !FLAGS_binary_output) {
+    parser.reset(
+        new grpc::testing::ProtoFileParser(FLAGS_remotedb ? channel : nullptr,
+                                           FLAGS_proto_path, FLAGS_proto_file));
+    if (parser->HasError()) {
+      return false;
+    }
+  }
+
+  if (FLAGS_binary_input) {
+    serialized_request_proto = request_text;
+  } else {
+    serialized_request_proto = parser->GetSerializedProtoFromMethod(
+        method_name, request_text, true /* is_request */);
+    if (parser->HasError()) {
+      return false;
+    }
+  }
+  fprintf(stderr, "connecting to %s\n", server_address.c_str());
+
+  grpc::string serialized_response_proto;
+  std::multimap<grpc::string, grpc::string> client_metadata;
+  std::multimap<grpc::string_ref, grpc::string_ref> server_initial_metadata,
+      server_trailing_metadata;
+  ParseMetadataFlag(&client_metadata);
+  PrintMetadata(client_metadata, "Sending client initial metadata:");
+  grpc::Status status = grpc::testing::CliCall::Call(
+      channel, parser->GetFormatedMethodName(method_name),
+      serialized_request_proto, &serialized_response_proto, client_metadata,
+      &server_initial_metadata, &server_trailing_metadata);
+  PrintMetadata(server_initial_metadata,
+                "Received initial metadata from server:");
+  PrintMetadata(server_trailing_metadata,
+                "Received trailing metadata from server:");
+  if (status.ok()) {
+    fprintf(stderr, "Rpc succeeded with OK status\n");
+    if (FLAGS_binary_output) {
+      output_ss << serialized_response_proto;
+    } else {
+      grpc::string response_text = parser->GetTextFormatFromMethod(
+          method_name, serialized_response_proto, false /* is_request */);
+      if (parser->HasError()) {
+        return false;
+      }
+      output_ss << "Response: \n " << response_text << std::endl;
+    }
+  } else {
+    fprintf(stderr, "Rpc failed with status code %d, error message: %s\n",
+            status.error_code(), status.error_message().c_str());
+  }
+
+  return callback(output_ss.str());
+}
+
+}  // namespace testing
+}  // namespace grpc
diff --git a/test/cpp/util/grpc_tool.h b/test/cpp/util/grpc_tool.h
new file mode 100644
index 0000000000..3da86937c2
--- /dev/null
+++ b/test/cpp/util/grpc_tool.h
@@ -0,0 +1,54 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_TEST_CPP_UTIL_GRPC_TOOL_H
+#define GRPC_TEST_CPP_UTIL_GRPC_TOOL_H
+
+#include <functional>
+
+#include <grpc++/support/config.h>
+
+#include "test/cpp/util/cli_credentials.h"
+
+namespace grpc {
+namespace testing {
+
+typedef std::function<bool(const grpc::string &)> GrpcToolOutputCallback;
+
+int GrpcToolMainLib(int argc, const char **argv, CliCredentials cred,
+                    GrpcToolOutputCallback callback);
+
+}  // namespace testing
+}  // namespace grpc
+
+#endif  // GRPC_TEST_CPP_UTIL_GRPC_TOOL_H
diff --git a/test/cpp/util/grpc_tool_test.cc b/test/cpp/util/grpc_tool_test.cc
new file mode 100644
index 0000000000..b96afaf50c
--- /dev/null
+++ b/test/cpp/util/grpc_tool_test.cc
@@ -0,0 +1,227 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "test/cpp/util/grpc_tool.h"
+
+#include <sstream>
+
+#include <grpc++/channel.h>
+#include <grpc++/client_context.h>
+#include <grpc++/create_channel.h>
+#include <grpc++/ext/proto_server_reflection_plugin.h>
+#include <grpc++/server.h>
+#include <grpc++/server_builder.h>
+#include <grpc++/server_context.h>
+#include <grpc/grpc.h>
+#include <gtest/gtest.h>
+
+#include "src/proto/grpc/testing/echo.grpc.pb.h"
+#include "src/proto/grpc/testing/echo.pb.h"
+#include "test/core/util/port.h"
+#include "test/core/util/test_config.h"
+#include "test/cpp/util/cli_credentials.h"
+#include "test/cpp/util/string_ref_helper.h"
+
+using grpc::testing::EchoRequest;
+using grpc::testing::EchoResponse;
+
+namespace grpc {
+namespace testing {
+namespace {
+
+class TestCliCredentials GRPC_FINAL : public grpc::testing::CliCredentials {
+ public:
+  std::shared_ptr<grpc::ChannelCredentials> GetCredentials() const
+      GRPC_OVERRIDE {
+    return InsecureChannelCredentials();
+  }
+  const grpc::string GetCredentialUsage() const GRPC_OVERRIDE { return ""; }
+};
+
+}  // namespame
+
+class TestServiceImpl : public ::grpc::testing::EchoTestService::Service {
+ public:
+  Status Echo(ServerContext* context, const EchoRequest* request,
+              EchoResponse* response) GRPC_OVERRIDE {
+    if (!context->client_metadata().empty()) {
+      for (std::multimap<grpc::string_ref, grpc::string_ref>::const_iterator
+               iter = context->client_metadata().begin();
+           iter != context->client_metadata().end(); ++iter) {
+        context->AddInitialMetadata(ToString(iter->first),
+                                    ToString(iter->second));
+      }
+    }
+    context->AddTrailingMetadata("trailing_key", "trailing_value");
+    response->set_message(request->message());
+    return Status::OK;
+  }
+};
+
+class GrpcToolTest : public ::testing::Test {
+ protected:
+  GrpcToolTest() {}
+
+  // SetUpServer cannot be used with EXPECT_EXIT. grpc_pick_unused_port_or_die()
+  // uses atexit() to free chosen ports, and it will spawn a new thread in
+  // resolve_address_posix.c:192 at exit time.
+  const grpc::string SetUpServer() {
+    std::ostringstream server_address;
+    int port = grpc_pick_unused_port_or_die();
+    server_address << "localhost:" << port;
+    // Setup server
+    ServerBuilder builder;
+    builder.AddListeningPort(server_address.str(), InsecureServerCredentials());
+    builder.RegisterService(&service_);
+    server_ = builder.BuildAndStart();
+    return server_address.str();
+  }
+
+  void ShutdownServer() { server_->Shutdown(); }
+
+  std::unique_ptr<Server> server_;
+  TestServiceImpl service_;
+  reflection::ProtoServerReflectionPlugin plugin_;
+};
+
+static bool PrintStream(std::stringstream* ss, const grpc::string& output) {
+  (*ss) << output << std::endl;
+  return true;
+}
+
+template <typename T>
+static size_t ArraySize(T& a) {
+  return ((sizeof(a) / sizeof(*(a))) /
+          static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))));
+}
+
+#define USAGE_REGEX "(  grpc_cli .+\n){2,10}"
+
+TEST_F(GrpcToolTest, NoCommand) {
+  // Test input "grpc_cli"
+  std::stringstream output_stream;
+  const char* argv[] = {"grpc_cli"};
+  // Exit with 1, print usage instruction in stderr
+  EXPECT_EXIT(
+      GrpcToolMainLib(
+          ArraySize(argv), argv, TestCliCredentials(),
+          std::bind(PrintStream, &output_stream, std::placeholders::_1)),
+      ::testing::ExitedWithCode(1), "No command specified\n" USAGE_REGEX);
+  // No output
+  EXPECT_TRUE(0 == output_stream.tellp());
+}
+
+TEST_F(GrpcToolTest, InvalidCommand) {
+  // Test input "grpc_cli"
+  std::stringstream output_stream;
+  const char* argv[] = {"grpc_cli", "abc"};
+  // Exit with 1, print usage instruction in stderr
+  EXPECT_EXIT(
+      GrpcToolMainLib(
+          ArraySize(argv), argv, TestCliCredentials(),
+          std::bind(PrintStream, &output_stream, std::placeholders::_1)),
+      ::testing::ExitedWithCode(1), "Invalid command 'abc'\n" USAGE_REGEX);
+  // No output
+  EXPECT_TRUE(0 == output_stream.tellp());
+}
+
+TEST_F(GrpcToolTest, HelpCommand) {
+  // Test input "grpc_cli help"
+  std::stringstream output_stream;
+  const char* argv[] = {"grpc_cli", "help"};
+  // Exit with 1, print usage instruction in stderr
+  EXPECT_EXIT(GrpcToolMainLib(ArraySize(argv), argv, TestCliCredentials(),
+                              std::bind(PrintStream, &output_stream,
+                                        std::placeholders::_1)),
+              ::testing::ExitedWithCode(1), USAGE_REGEX);
+  // No output
+  EXPECT_TRUE(0 == output_stream.tellp());
+}
+
+TEST_F(GrpcToolTest, CallCommand) {
+  // Test input "grpc_cli call Echo"
+  std::stringstream output_stream;
+
+  const grpc::string server_address = SetUpServer();
+  const char* argv[] = {"grpc_cli", "call", server_address.c_str(), "Echo",
+                        "message: 'Hello'"};
+
+  EXPECT_TRUE(0 == GrpcToolMainLib(ArraySize(argv), argv, TestCliCredentials(),
+                                   std::bind(PrintStream, &output_stream,
+                                             std::placeholders::_1)));
+  // Expected output: "message: \"Hello\""
+  EXPECT_TRUE(NULL !=
+              strstr(output_stream.str().c_str(), "message: \"Hello\""));
+  ShutdownServer();
+}
+
+TEST_F(GrpcToolTest, TooFewArguments) {
+  // Test input "grpc_cli call localhost:<port> Echo "message: 'Hello'"
+  std::stringstream output_stream;
+  const char* argv[] = {"grpc_cli", "call", "Echo"};
+
+  // Exit with 1
+  EXPECT_EXIT(
+      GrpcToolMainLib(
+          ArraySize(argv), argv, TestCliCredentials(),
+          std::bind(PrintStream, &output_stream, std::placeholders::_1)),
+      ::testing::ExitedWithCode(1), ".*Wrong number of arguments for call.*");
+  // No output
+  EXPECT_TRUE(0 == output_stream.tellp());
+}
+
+TEST_F(GrpcToolTest, TooManyArguments) {
+  // Test input "grpc_cli call localhost:<port> Echo Echo "message: 'Hello'"
+  std::stringstream output_stream;
+  const char* argv[] = {"grpc_cli", "call", "localhost:10000",
+                        "Echo",     "Echo", "message: 'Hello'"};
+
+  // Exit with 1
+  EXPECT_EXIT(
+      GrpcToolMainLib(
+          ArraySize(argv), argv, TestCliCredentials(),
+          std::bind(PrintStream, &output_stream, std::placeholders::_1)),
+      ::testing::ExitedWithCode(1), ".*Wrong number of arguments for call.*");
+  // No output
+  EXPECT_TRUE(0 == output_stream.tellp());
+}
+
+}  // namespace testing
+}  // namespace grpc
+
+int main(int argc, char** argv) {
+  grpc_test_init(argc, argv);
+  ::testing::InitGoogleTest(&argc, argv);
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  return RUN_ALL_TESTS();
+}
diff --git a/test/cpp/util/proto_file_parser.cc b/test/cpp/util/proto_file_parser.cc
index 5b0d925e1c..0c88c24448 100644
--- a/test/cpp/util/proto_file_parser.cc
+++ b/test/cpp/util/proto_file_parser.cc
@@ -37,7 +37,6 @@
 #include <iostream>
 #include <sstream>
 
-#include <google/protobuf/text_format.h>
 #include <grpc++/support/config.h>
 
 namespace grpc {
@@ -56,8 +55,7 @@ bool MethodNameMatch(const grpc::string& full_name, const grpc::string& input) {
 }
 }  // namespace
 
-class ErrorPrinter
-    : public google::protobuf::compiler::MultiFileErrorCollector {
+class ErrorPrinter : public protobuf::compiler::MultiFileErrorCollector {
  public:
   explicit ErrorPrinter(ProtoFileParser* parser) : parser_(parser) {}
 
@@ -71,7 +69,7 @@ class ErrorPrinter
 
   void AddWarning(const grpc::string& filename, int line, int column,
                   const grpc::string& message) GRPC_OVERRIDE {
-    std::cout << "warning " << filename << " " << line << " " << column << " "
+    std::cerr << "warning " << filename << " " << line << " " << column << " "
               << message << std::endl;
   }
 
@@ -79,62 +77,69 @@ class ErrorPrinter
   ProtoFileParser* parser_;  // not owned
 };
 
-ProtoFileParser::ProtoFileParser(const grpc::string& proto_path,
-                                 const grpc::string& file_name,
-                                 const grpc::string& method)
+ProtoFileParser::ProtoFileParser(std::shared_ptr<grpc::Channel> channel,
+                                 const grpc::string& proto_path,
+                                 const grpc::string& protofiles)
     : has_error_(false) {
-  source_tree_.MapPath("", proto_path);
-  error_printer_.reset(new ErrorPrinter(this));
-  importer_.reset(new google::protobuf::compiler::Importer(
-      &source_tree_, error_printer_.get()));
-  const auto* file_desc = importer_->Import(file_name);
-  if (!file_desc) {
-    LogError("");
-    return;
+  std::vector<std::string> service_list;
+  if (channel) {
+    reflection_db_.reset(new grpc::ProtoReflectionDescriptorDatabase(channel));
+    reflection_db_->GetServices(&service_list);
   }
-  dynamic_factory_.reset(
-      new google::protobuf::DynamicMessageFactory(importer_->pool()));
 
-  std::vector<const google::protobuf::ServiceDescriptor*> service_desc_list;
-  for (int i = 0; i < file_desc->service_count(); i++) {
-    service_desc_list.push_back(file_desc->service(i));
-  }
-  InitProtoFileParser(method, service_desc_list);
-}
+  if (!protofiles.empty()) {
+    source_tree_.MapPath("", proto_path);
+    error_printer_.reset(new ErrorPrinter(this));
+    importer_.reset(
+        new protobuf::compiler::Importer(&source_tree_, error_printer_.get()));
 
-ProtoFileParser::ProtoFileParser(std::shared_ptr<grpc::Channel> channel,
-                                 const grpc::string& method)
-    : has_error_(false),
-      desc_db_(new grpc::ProtoReflectionDescriptorDatabase(channel)),
-      desc_pool_(new google::protobuf::DescriptorPool(desc_db_.get())) {
-  std::vector<std::string> service_list;
-  if (!desc_db_->GetServices(&service_list)) {
-    LogError(
-        "Failed to get services from the server, "
-        "it may not have the reflection service.\n"
-        "Please try to use the --protofiles option to provide a proto file.");
+    grpc::string file_name;
+    std::stringstream ss(protofiles);
+    while (std::getline(ss, file_name, ',')) {
+      const auto* file_desc = importer_->Import(file_name);
+      if (file_desc) {
+        for (int i = 0; i < file_desc->service_count(); i++) {
+          service_desc_list_.push_back(file_desc->service(i));
+        }
+      } else {
+        std::cerr << file_name << " not found" << std::endl;
+      }
+    }
+
+    file_db_.reset(new protobuf::DescriptorPoolDatabase(*importer_->pool()));
   }
-  if (has_error_) {
+
+  if (!reflection_db_ && !file_db_) {
+    LogError("No available proto database");
     return;
   }
-  dynamic_factory_.reset(
-      new google::protobuf::DynamicMessageFactory(desc_pool_.get()));
 
-  std::vector<const google::protobuf::ServiceDescriptor*> service_desc_list;
+  if (!reflection_db_) {
+    desc_db_ = std::move(file_db_);
+  } else if (!file_db_) {
+    desc_db_ = std::move(reflection_db_);
+  } else {
+    desc_db_.reset(new protobuf::MergedDescriptorDatabase(reflection_db_.get(),
+                                                          file_db_.get()));
+  }
+
+  desc_pool_.reset(new protobuf::DescriptorPool(desc_db_.get()));
+  dynamic_factory_.reset(new protobuf::DynamicMessageFactory(desc_pool_.get()));
+
   for (auto it = service_list.begin(); it != service_list.end(); it++) {
-    service_desc_list.push_back(desc_pool_->FindServiceByName(*it));
+    if (const protobuf::ServiceDescriptor* service_desc =
+            desc_pool_->FindServiceByName(*it)) {
+      service_desc_list_.push_back(service_desc);
+    }
   }
-  InitProtoFileParser(method, service_desc_list);
 }
 
 ProtoFileParser::~ProtoFileParser() {}
 
-void ProtoFileParser::InitProtoFileParser(
-    const grpc::string& method,
-    const std::vector<const google::protobuf::ServiceDescriptor*>
-        service_desc_list) {
-  const google::protobuf::MethodDescriptor* method_descriptor = nullptr;
-  for (auto it = service_desc_list.begin(); it != service_desc_list.end();
+grpc::string ProtoFileParser::GetFullMethodName(const grpc::string& method) {
+  has_error_ = false;
+  const protobuf::MethodDescriptor* method_descriptor = nullptr;
+  for (auto it = service_desc_list_.begin(); it != service_desc_list_.end();
        it++) {
     const auto* service_desc = *it;
     for (int j = 0; j < service_desc->method_count(); j++) {
@@ -154,28 +159,82 @@ void ProtoFileParser::InitProtoFileParser(
     LogError("Method name not found");
   }
   if (has_error_) {
-    return;
+    return "";
+  }
+
+  return method_descriptor->full_name();
+}
+
+grpc::string ProtoFileParser::GetFormatedMethodName(
+    const grpc::string& method) {
+  has_error_ = false;
+  grpc::string formated_method_name = GetFullMethodName(method);
+  if (has_error_) {
+    return "";
   }
-  full_method_name_ = method_descriptor->full_name();
-  size_t last_dot = full_method_name_.find_last_of('.');
+  size_t last_dot = formated_method_name.find_last_of('.');
   if (last_dot != grpc::string::npos) {
-    full_method_name_[last_dot] = '/';
+    formated_method_name[last_dot] = '/';
+  }
+  formated_method_name.insert(formated_method_name.begin(), '/');
+  return formated_method_name;
+}
+
+grpc::string ProtoFileParser::GetMessageTypeFromMethod(
+    const grpc::string& method, bool is_request) {
+  has_error_ = false;
+  grpc::string full_method_name = GetFullMethodName(method);
+  if (has_error_) {
+    return "";
+  }
+  const protobuf::MethodDescriptor* method_desc =
+      desc_pool_->FindMethodByName(full_method_name);
+  if (!method_desc) {
+    LogError("Method not found");
+    return "";
   }
-  full_method_name_.insert(full_method_name_.begin(), '/');
 
-  request_prototype_.reset(
-      dynamic_factory_->GetPrototype(method_descriptor->input_type())->New());
-  response_prototype_.reset(
-      dynamic_factory_->GetPrototype(method_descriptor->output_type())->New());
+  return is_request ? method_desc->input_type()->full_name()
+                    : method_desc->output_type()->full_name();
 }
 
-grpc::string ProtoFileParser::GetSerializedProto(
-    const grpc::string& text_format_proto, bool is_request) {
+grpc::string ProtoFileParser::GetSerializedProtoFromMethod(
+    const grpc::string& method, const grpc::string& text_format_proto,
+    bool is_request) {
+  has_error_ = false;
+  grpc::string message_type_name = GetMessageTypeFromMethod(method, is_request);
+  if (has_error_) {
+    return "";
+  }
+  return GetSerializedProtoFromMessageType(message_type_name,
+                                           text_format_proto);
+}
+
+grpc::string ProtoFileParser::GetTextFormatFromMethod(
+    const grpc::string& method, const grpc::string& serialized_proto,
+    bool is_request) {
+  has_error_ = false;
+  grpc::string message_type_name = GetMessageTypeFromMethod(method, is_request);
+  if (has_error_) {
+    return "";
+  }
+  return GetTextFormatFromMessageType(message_type_name, serialized_proto);
+}
+
+grpc::string ProtoFileParser::GetSerializedProtoFromMessageType(
+    const grpc::string& message_type_name,
+    const grpc::string& text_format_proto) {
+  has_error_ = false;
   grpc::string serialized;
-  grpc::protobuf::Message* msg =
-      is_request ? request_prototype_.get() : response_prototype_.get();
-  bool ok =
-      google::protobuf::TextFormat::ParseFromString(text_format_proto, msg);
+  const protobuf::Descriptor* desc =
+      desc_pool_->FindMessageTypeByName(message_type_name);
+  if (!desc) {
+    LogError("Message type not found");
+    return "";
+  }
+  std::unique_ptr<grpc::protobuf::Message> msg(
+      dynamic_factory_->GetPrototype(desc)->New());
+  bool ok = protobuf::TextFormat::ParseFromString(text_format_proto, msg.get());
   if (!ok) {
     LogError("Failed to parse text format to proto.");
     return "";
@@ -188,16 +247,24 @@ grpc::string ProtoFileParser::GetSerializedProto(
   return serialized;
 }
 
-grpc::string ProtoFileParser::GetTextFormat(
-    const grpc::string& serialized_proto, bool is_request) {
-  grpc::protobuf::Message* msg =
-      is_request ? request_prototype_.get() : response_prototype_.get();
+grpc::string ProtoFileParser::GetTextFormatFromMessageType(
+    const grpc::string& message_type_name,
+    const grpc::string& serialized_proto) {
+  has_error_ = false;
+  const protobuf::Descriptor* desc =
+      desc_pool_->FindMessageTypeByName(message_type_name);
+  if (!desc) {
+    LogError("Message type not found");
+    return "";
+  }
+  std::unique_ptr<grpc::protobuf::Message> msg(
+      dynamic_factory_->GetPrototype(desc)->New());
   if (!msg->ParseFromString(serialized_proto)) {
     LogError("Failed to deserialize proto.");
     return "";
   }
   grpc::string text_format;
-  if (!google::protobuf::TextFormat::PrintToString(*msg, &text_format)) {
+  if (!protobuf::TextFormat::PrintToString(*msg.get(), &text_format)) {
     LogError("Failed to print proto message to text format");
     return "";
   }
@@ -206,7 +273,7 @@ grpc::string ProtoFileParser::GetTextFormat(
 
 void ProtoFileParser::LogError(const grpc::string& error_msg) {
   if (!error_msg.empty()) {
-    std::cout << error_msg << std::endl;
+    std::cerr << error_msg << std::endl;
   }
   has_error_ = true;
 }
diff --git a/test/cpp/util/proto_file_parser.h b/test/cpp/util/proto_file_parser.h
index b442d77db9..eda3991e72 100644
--- a/test/cpp/util/proto_file_parser.h
+++ b/test/cpp/util/proto_file_parser.h
@@ -36,11 +36,9 @@
 
 #include <memory>
 
-#include <google/protobuf/compiler/importer.h>
-#include <google/protobuf/dynamic_message.h>
 #include <grpc++/channel.h>
 
-#include "src/compiler/config.h"
+#include "test/cpp/util/config_grpc_cli.h"
 #include "test/cpp/util/proto_reflection_descriptor_database.h"
 
 namespace grpc {
@@ -50,44 +48,63 @@ class ErrorPrinter;
 // Find method and associated request/response types.
 class ProtoFileParser {
  public:
-  // The given proto file_name will be searched in a source tree rooted from
-  // proto_path. The method could be a partial string such as Service.Method or
-  // even just Method. It will log an error if there is ambiguity.
-  ProtoFileParser(const grpc::string& proto_path, const grpc::string& file_name,
-                  const grpc::string& method);
-
+  // The parser will search proto files using the server reflection service
+  // provided on the given channel. The given protofiles in a source tree rooted
+  // from proto_path will also be searched.
   ProtoFileParser(std::shared_ptr<grpc::Channel> channel,
-                  const grpc::string& method);
+                  const grpc::string& proto_path,
+                  const grpc::string& protofiles);
+
   ~ProtoFileParser();
 
-  grpc::string GetFullMethodName() const { return full_method_name_; }
+  // The input method name in the following four functions could be a partial
+  // string such as Service.Method or even just Method. It will log an error if
+  // there is ambiguity.
+  // Full method name is in the form of Service.Method, it's good to be used in
+  // descriptor database queries.
+  grpc::string GetFullMethodName(const grpc::string& method);
+
+  // Formated method name is in the form of /Service/Method, it's good to be
+  // used as the argument of Stub::Call()
+  grpc::string GetFormatedMethodName(const grpc::string& method);
+
+  grpc::string GetSerializedProtoFromMethod(
+      const grpc::string& method, const grpc::string& text_format_proto,
+      bool is_request);
+
+  grpc::string GetTextFormatFromMethod(const grpc::string& method,
+                                       const grpc::string& serialized_proto,
+                                       bool is_request);
 
-  grpc::string GetSerializedProto(const grpc::string& text_format_proto,
-                                  bool is_request);
+  grpc::string GetSerializedProtoFromMessageType(
+      const grpc::string& message_type_name,
+      const grpc::string& text_format_proto);
 
-  grpc::string GetTextFormat(const grpc::string& serialized_proto,
-                             bool is_request);
+  grpc::string GetTextFormatFromMessageType(
+      const grpc::string& message_type_name,
+      const grpc::string& serialized_proto);
 
   bool HasError() const { return has_error_; }
 
   void LogError(const grpc::string& error_msg);
 
  private:
-  void InitProtoFileParser(
-      const grpc::string& method,
-      const std::vector<const google::protobuf::ServiceDescriptor*> services);
+  grpc::string GetMessageTypeFromMethod(const grpc::string& method,
+                                        bool is_request);
 
   bool has_error_;
   grpc::string request_text_;
-  grpc::string full_method_name_;
-  google::protobuf::compiler::DiskSourceTree source_tree_;
+  protobuf::compiler::DiskSourceTree source_tree_;
   std::unique_ptr<ErrorPrinter> error_printer_;
-  std::unique_ptr<google::protobuf::compiler::Importer> importer_;
-  std::unique_ptr<grpc::ProtoReflectionDescriptorDatabase> desc_db_;
-  std::unique_ptr<google::protobuf::DescriptorPool> desc_pool_;
-  std::unique_ptr<google::protobuf::DynamicMessageFactory> dynamic_factory_;
+  std::unique_ptr<protobuf::compiler::Importer> importer_;
+  std::unique_ptr<grpc::ProtoReflectionDescriptorDatabase> reflection_db_;
+  std::unique_ptr<protobuf::DescriptorPoolDatabase> file_db_;
+  std::unique_ptr<protobuf::DescriptorDatabase> desc_db_;
+  std::unique_ptr<protobuf::DescriptorPool> desc_pool_;
+  std::unique_ptr<protobuf::DynamicMessageFactory> dynamic_factory_;
   std::unique_ptr<grpc::protobuf::Message> request_prototype_;
   std::unique_ptr<grpc::protobuf::Message> response_prototype_;
+  std::vector<const protobuf::ServiceDescriptor*> service_desc_list_;
 };
 
 }  // namespace testing
diff --git a/test/cpp/util/proto_reflection_descriptor_database.cc b/test/cpp/util/proto_reflection_descriptor_database.cc
index 8fd466feb0..f0d14c686a 100644
--- a/test/cpp/util/proto_reflection_descriptor_database.cc
+++ b/test/cpp/util/proto_reflection_descriptor_database.cc
@@ -58,7 +58,7 @@ ProtoReflectionDescriptorDatabase::~ProtoReflectionDescriptorDatabase() {
     stream_->WritesDone();
     Status status = stream_->Finish();
     if (!status.ok()) {
-      gpr_log(GPR_ERROR,
+      gpr_log(GPR_INFO,
               "ServerReflectionInfo rpc failed. Error code: %d, details: %s",
               (int)status.error_code(), status.error_message().c_str());
     }