[ISSUE #28]: 支持域名解析

polaris/grpc/http2.cpp

@@ -16,9 +16,11 @@
 #include <arpa/inet.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <netdb.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <poll.h>
+#include <re2/re2.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -347,6 +349,45 @@ Http2Client::~Http2Client() {
   }
 }
 
+// TryLookup 尝试进行 host 解析
+// step 1. 判断当前的 host 是否是域名
+// step 2. 不是域名，则直接返回
+// step 3. 是域名，进行一次域名解析，然后从返回的IPList中随机选取一个IP进行链接
+static std::string TryLookup(const std::string& address) {
+  GRPC_LOG(LOG_DEBUG, "try lookup address=[%s]", address.c_str());
+
+  std::string domain_reg =
+      "^[a-zA-Z0-9][-a-zA-Z0-9]{0,62}(\\.[a-zA-Z0-9][-a-zA-Z0-9]{0,62})+\\.?$";
+  re2::RE2 domain(domain_reg.c_str());
+  bool is_domain = domain.ok() && re2::RE2::PartialMatch(address.c_str(), domain);
+
+  // 使用正则表达式判断是否是域名, 不是域名，直接返回 address
+  if (!is_domain) {
+    return address;
+  }
+
+  struct hostent* host = gethostbyname(address.c_str());
+  if (!host) {
+    GRPC_LOG(LOG_ERROR, "try lookup address=[%s] error, maybe address is ip", address.c_str());
+    return address;
+  }
+
+  GRPC_LOG(LOG_DEBUG, "address=[%s] type: [%s]", address.c_str(),
+           (host->h_addrtype == AF_INET) ? "AF_INET" : "AF_INET6");
+
+  int total = sizeof(host->h_addr_list);
+  if (total < 1) {
+    return address;
+  }
+
+  std::string target_address = inet_ntoa(*(struct in_addr*)host->h_addr_list[0]);
+
+  GRPC_LOG(LOG_TRACE, "address=[%s] select one by random [%s]", address.c_str(),
+           target_address.c_str());
+
+  return target_address;
+}
+
 // 向指定地址发起非阻塞连接
 static int TryConnectTo(const std::string& host, int port, int& fd) {
   if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
@@ -368,30 +409,34 @@ static int TryConnectTo(const std::string& host, int port, int& fd) {
   bzero(static_cast<void*>(&addr), sizeof(struct sockaddr_in));
   addr.sin_family = AF_INET;
   addr.sin_port   = htons(port);
+
   if (inet_pton(AF_INET, host.c_str(), &addr.sin_addr) != 1) {
     return -1;
   }
   return connect(fd, (struct sockaddr*)&addr, sizeof(addr));
 }
 
 bool Http2Client::ConnectTo(const std::string& host, int port) {
+  std::string server_ip = TryLookup(host);
+
   POLARIS_ASSERT(state_ == kConnectionInit);
-  GRPC_LOG(LOG_INFO, "try to nonblocking connect to server[%s:%d]", host.c_str(), port);
+  GRPC_LOG(LOG_INFO, "try to nonblocking connect to server[%s:%d]", server_ip.c_str(), port);
   int retcode = TryConnectTo(host, port, fd_);
   if (retcode == 0) {  // 异步连接立即成功了，一般本地连接才有可能发生。
-    GRPC_LOG(LOG_TRACE, "nonblocking connect to service[%s:%d] success immediately", host.c_str(),
-             port);
+    GRPC_LOG(LOG_TRACE, "nonblocking connect to service[%s:%d] success immediately",
+             server_ip.c_str(), port);
     state_ = kConnectionConnecting;  // 即使立刻连接成功了也放在epoll写事件中去更新状态
   } else if (errno == EINPROGRESS) {  // tcp connect return -1
     state_ = kConnectionConnecting;
     GRPC_LOG(LOG_TRACE, "nonblocking connect to server[%s:%d] with connection in progress",
-             host.c_str(), port);
+             server_ip.c_str(), port);
     retcode = 0;
   } else {
     state_ = kConnectionDisconnected;
-    GRPC_LOG(LOG_ERROR, "nonblocking connect to %s:%d with error: %d", host.c_str(), port, errno);
+    GRPC_LOG(LOG_ERROR, "nonblocking connect to %s:%d with error: %d", server_ip.c_str(), port,
+             errno);
   }
-  current_server_ = host + ":" + StringUtils::TypeToStr<int>(port);
+  current_server_ = server_ip + ":" + StringUtils::TypeToStr<int>(port);
   return retcode == 0;
 }
 

test/grpc/domain_test.cpp

@@ -0,0 +1,49 @@
+//  Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+//
+//  Licensed under the BSD 3-Clause License (the "License"); you may not use
+//  this file
+//  except in compliance with the License. You may obtain a copy of the License
+//  at
+//
+//  https://opensource.org/licenses/BSD-3-Clause
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed
+//  under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+//  CONDITIONS OF ANY KIND, either express or implied. See the License for the
+//  specific
+//  language governing permissions and limitations under the License.
+//
+
+#include "grpc/buffer.h"
+
+#include <gtest/gtest.h>
+#include <pthread.h>
+#include <re2/re2.h>
+#include <unistd.h>
+
+namespace polaris {
+namespace grpc {
+
+class GrpcDomainTest : public ::testing::Test {
+protected:
+  virtual void SetUp() {}
+
+  virtual void TearDown() {}
+
+protected:
+};
+
+TEST_F(GrpcDomainTest, DomainJudge) {
+  std::string domain_reg = "^[a-zA-Z0-9][-a-zA-Z0-9]{0,62}(\\.[a-zA-Z0-9][-a-zA-Z0-9]{0,62})+\\.?$";
+  re2::RE2 regex_(domain_reg.c_str());
+  ASSERT_TRUE((regex_).ok());
+  std::string str_1 = "baidu.com";
+  ASSERT_TRUE(re2::RE2::PartialMatch(str_1.c_str(), regex_));
+
+  std::string str_2 = "polaris.default.svc.local";
+  ASSERT_TRUE(re2::RE2::PartialMatch(str_2.c_str(), regex_));
+}
+
+}  // namespace grpc
+}  // namespace polaris

test/grpc/grpc_client_test.cpp

@@ -15,9 +15,9 @@
 //  language governing permissions and limitations under the License.
 //
 
-#include "grpc/client.h"
-
 #include <gtest/gtest.h>
+#include "grpc/client.h"
+#include "grpc/http2.cpp"
 
 #include "mock/fake_net_server.h"
 #include "reactor/reactor.h"