feat(fqdn): giving some time for FQDN resolution

Signed-off-by: Raphael Defosseux <raphael.defosseux@openairinterface.org>

src/common/utils/fqdn.cpp

@@ -23,12 +23,19 @@
 #include "logger.hpp"
 #include <boost/asio.hpp>
 #include <iostream>
+#include <unistd.h>
+
+#define MAX_NB_RESOLVE_TRIES 4
+#define TIME_BETWEEN_TRIES 2
 
 bool fqdn::resolve(
     const std::string& host_name, std::string& address, uint32_t& port,
     uint8_t& addr_type, const std::string& protocol) {
+  int tries = 0;
+  while (tries < MAX_NB_RESOLVE_TRIES) {
     try {
       boost::asio::io_context io_context = {};
+      Logger::smf_app().debug("Resolving DNS Try #%u", tries);
 
       boost::asio::ip::tcp::resolver resolver{io_context};
       boost::asio::ip::tcp::resolver::results_type endpoints =
@@ -50,10 +57,16 @@ bool fqdn::resolve(
         return true;
       }
     } catch (std::exception& e) {
+      tries++;
+      if (tries == MAX_NB_RESOLVE_TRIES) {
         throw std::runtime_error(
-        "Cannot resolve a DNS name " + std::string(e.what()));
+            "Cannot resolve a DNS name " + std::string(e.what()) + " after " +
+            std::to_string(tries) + " tries");
         return false;
       }
+      sleep(TIME_BETWEEN_TRIES);
+    }
+  }
 
   return false;
 }