Add simple logging to a file

Reviewers: buda

Reviewed By: buda

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D476

CMakeLists.txt

@@ -159,7 +159,13 @@ endif()
 # -----------------------------------------------------------------------------
 
 # logging levels --------------------------------------------------------------
+option (LOG_NO_STDOUT
+        "Disable logging to stdout. (Docker has a bug with large logs.)"
+        OFF)
 option(LOG_NO_TRACE "Disable trace logging" OFF)
+if (LOG_NO_STDOUT)
+    add_definitions(-DLOG_NO_STDOUT)
+endif()
 message(STATUS "LOG_NO_TRACE: ${LOG_NO_TRACE}")
 if (LOG_NO_TRACE)
     add_definitions(-DLOG_NO_TRACE)

src/communication/server.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <atomic>
+#include <iostream>
 #include <memory>
 #include <thread>
 #include <vector>
@@ -63,6 +64,12 @@ class Server
               dbms_, query_engine_));
       workers_.back()->Start(alive_);
     }
+#ifdef LOG_NO_STDOUT
+    // TODO: Remove this when we switch to glog.
+    std::cout << "Server is fully armed and operational" << std::endl
+              << "Listening on " << socket_.endpoint().address() << " at "
+              << socket_.endpoint().port() << std::endl;
+#endif
     logger_.info("Server is fully armed and operational");
     logger_.info("Listening on {} at {}", socket_.endpoint().address(),
                  socket_.endpoint().port());
@@ -70,6 +77,10 @@ class Server
       this->WaitAndProcessEvents();
     }
 
+#ifdef LOG_NO_STDOUT
+    // TODO: Remove this when we switch to glog.
+    std::cout << "Shutting down..." << std::endl;
+#endif
     logger_.info("Shutting down...");
     for (auto &worker : workers_) worker->thread_.join();
   }

src/logging/streams/file.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "logging/log.hpp"
+#include "logging/streams/format.hpp"
+
+class File : public Log::Stream {
+ public:
+  File(const std::string &filename) : file_(filename) {}
+  void emit(const Log::Record &record) override {
+    file_ << logging::Formatter::format(logging::format::out, record);
+    file_.flush();
+  }
+
+ private:
+  std::ofstream file_;
+};
+

src/memgraph_bolt.cpp

@@ -15,6 +15,7 @@
 
 #include "logging/default.hpp"
 #include "logging/streams/stdout.hpp"
+#include "logging/streams/file.hpp"
 
 #include "utils/flag_validation.hpp"
 #include "utils/signals/handler.hpp"
@@ -38,6 +39,8 @@ DEFINE_string(port, "7687", "Default port on which to listen.");
 DEFINE_VALIDATED_int32(num_workers,
                        std::max(std::thread::hardware_concurrency(), 1U),
                        "Number of workers", FLAG_IN_RANGE(1, INT32_MAX));
+DEFINE_string(log_file, "memgraph.log",
+              "Path to where the log should be stored.");
 
 // Load flags in this order, the last one has the highest priority:
 // 1) /etc/memgraph/config
@@ -90,7 +93,10 @@ int main(int argc, char **argv) {
 #else
   logging::init_async();
 #endif
+#ifndef LOG_NO_STDOUT
   logging::log->pipe(std::make_unique<Stdout>());
+#endif
+  logging::log->pipe(std::make_unique<File>(FLAGS_log_file));
 
   // Get logger.
   logger = logging::log->logger("Main");