PXC-3423: Introduce a garbd variable to enable logging of debugging

          information to the error log

https://jira.percona.com/browse/PXC-3423

This patch introduces "--debug" variable to garbd to enable logging of
debugging information in garbd.

garb/garb_config.cpp

@@ -46,12 +46,14 @@ Config::Config (int argc, char* argv[])
       cfg_     (),
       recv_script_ (),
       workdir_ (),
+      debug_   (false),
       exit_    (false)
 {
     po::options_description other ("Other options");
     other.add_options()
         ("version,v", "Print version & exit")
         ("help,h",    "Show help message & exit")
+        ("debug",     "Enable debug prints")
         ;
 
     // only these are read from cfg file
@@ -66,8 +68,7 @@ Config::Config (int argc, char* argv[])
         ("options,o",   po::value<std::string>(&options_),     "GCS/GCOMM option list")
         ("log,l",       po::value<std::string>(&log_),         "Log file")
         ("recv-script", po::value<std::string>(&recv_script_), "SST request receive script")
-        ("workdir,w",po::value<std::string>(&workdir_),
-         "Daemon working directory")
+        ("workdir,w",po::value<std::string>(&workdir_),        "Daemon working directory")
         ;
 
     po::options_description cfg_opt;
@@ -103,6 +104,12 @@ Config::Config (int argc, char* argv[])
         return;
     }
 
+    if (vm.count("debug"))
+    {
+        debug_ = true;
+        gu_conf_debug_on();
+    }
+
     if (vm.count("cfg"))
     {
         std::ifstream ifs(cfg_.c_str());
@@ -201,7 +208,8 @@ std::ostream& operator << (std::ostream& os, const Config& c)
        << "\n\tcfg:         " << c.cfg()
        << "\n\tlog:         " << c.log()
        << "\n\trecv_script: " << c.recv_script()
-       << "\n\tworkdir: " << c.workdir();
+       << "\n\tworkdir:     " << c.workdir()
+       << "\n\tdebug:       " << c.debug();;
     return os;
 }
 

garb/garb_config.hpp

@@ -29,6 +29,7 @@ class Config
     const std::string& log()     const { return log_    ; }
     const std::string& workdir() const { return workdir_; }
     bool               exit()    const { return exit_   ; }
+    bool               debug()    const { return debug_   ; }
     const std::string& recv_script() const { return recv_script_    ; }
 
 private:
@@ -44,6 +45,7 @@ class Config
     std::string cfg_;
     std::string recv_script_;
     std::string workdir_;
+    bool debug_;
     bool exit_; /* Exit on --help or --version */
 
 }; /* class Config */