[alohalytics] FastCGI server basic implementation.

3party/Alohalytics/server/fcgi_server.cc

@@ -0,0 +1,131 @@
+/*******************************************************************************
+ The MIT License (MIT)
+
+ Copyright (c) 2015 Alexander Zolotarev <me@alex.bio> from Minsk, Belarus
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in all
+ copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+ *******************************************************************************/
+
+// This FastCGI server implementation is designed to store statistics received from remote clients.
+
+// Validity checks for requests should be mostly done on nginx side:
+// $request_method should be POST only
+// $content_length should be set and greater than zero (we re-check it below anyway)
+// $content_type should be set to application/alohalytics-binary-blob
+// $http_content_encoding should be set to gzip
+
+#include <chrono>
+
+#include <cstdlib>
+#include <ctime>
+#include <exception>
+#include <fstream>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <thread>
+
+#include <fcgiapp.h>
+#include <fcgio.h>
+
+#include "../src/file_manager.h"
+#include "../src/logger.h"
+
+#include "statistics_receiver.h"
+
+using namespace std;
+
+// Can be used as a basic check on the client-side if it has connected to the right server.
+static const string kBodyTextInSuccessfulServerReply = "Mahalo";
+
+// TODO(AlexZ): Pass log file as a command line parameter and use it for logging when running as daemon.
+int main(int argc, char * argv[]) {
+  if (argc < 2) {
+    ALOG("Usage:", argv[0], "<directory to store received data>");
+    return -1;
+  }
+  int result = FCGX_Init();
+  if (0 != result) {
+    ALOG("ERROR: FCGX_Init has failed with code", result);
+    return result;
+  }
+  FCGX_Request request;
+  result = FCGX_InitRequest(&request, 0, FCGI_FAIL_ACCEPT_ON_INTR);
+  if (0 != result) {
+    ALOG("ERROR: FCGX_InitRequest has failed with code", result);
+    return result;
+  }
+  alohalytics::StatisticsReceiver receiver(argv[1]);
+  ALOG("FastCGI Server instance is ready to serve clients' requests.");
+  while (FCGX_Accept_r(&request) >= 0) {
+    try {
+      const char * content_length_str = FCGX_GetParam("HTTP_CONTENT_LENGTH", request.envp);
+      long long content_length;
+      if (!content_length_str || ((content_length = atoll(content_length_str)) <= 0)) {
+        ALOG("WARNING: Invalid or missing Content-Length header, request is ignored.");
+        FCGX_FPrintF(request.out,
+                     "Status: 411 Length Required\r\nContent-Type: text/plain\r\n\r\n411 Length Required\n");
+        continue;
+      }
+      unique_ptr<char[]> body(new char[content_length]);
+      if (fcgi_istream(request.in).read(body.get(), content_length).fail()) {
+        ALOG("WARNING: Can't read body contents, request is ignored.");
+        FCGX_FPrintF(request.out, "Status: 400 Bad Request\r\nContent-Type: text/plain\r\n\r\n400 Bad Request\n");
+        continue;
+      }
+
+      //      FCGX_FPrintF(request.out, "Content-Type: text/plain\r\n\r\n");
+      //      for (char ** p = request.envp; *p; ++p) {
+      //        FCGX_FPrintF(request.out, "%s\n", *p);
+      //      }
+
+      const char * user_agent_str = FCGX_GetParam("HTTP_USER_AGENT", request.envp);
+      if (user_agent_str) {
+      } else {
+        ALOG("WARNING: Missing HTTP User-Agent.");
+      }
+      const char * request_uri_str = FCGX_GetParam("REQUEST_URI", request.envp);
+      if (request_uri_str) {
+      } else {
+        ALOG("WARNING: Missing REQUEST_URI.");
+      }
+      const char * remote_addr_str = FCGX_GetParam("REMOTE_ADDR", request.envp);
+      if (remote_addr_str) {
+      } else {
+        ALOG("WARNING: Missing REMOTE_ADDR.");
+      }
+
+      // Process received body.
+
+      ALOG("Successfully processed request:", string(body.get(), content_length));
+      FCGX_FPrintF(request.out, "Status: 200 OK\r\nContent-Type: text/plain\r\nContent-Length: %ld\r\n\r\n%s\n",
+                   kBodyTextInSuccessfulServerReply.size(), kBodyTextInSuccessfulServerReply.c_str());
+
+    } catch (const std::exception & ex) {
+      ALOG("ERROR: Exception while processing request: ", ex.what());
+      FCGX_FPrintF(request.out,
+                   "Status: 500 Internal Server Error\r\nContent-Type: text/plain\r\n\r\n500 Internal Server Error\n");
+      // TODO(AlexZ): Full log here to get more details. Also think about clients who can constantly fail because of bad
+      // data file.
+      continue;
+    }
+  }
+  ALOG("Shutting down FastCGI server instance.");
+  return 0;
+}