Improve log nat manager (#1058)

Improvement of nat manager logs to avoid false positives when running on a kubernetes environment.

Signed-off-by: Karim TAAM <karim.t2am@gmail.com>

nat/src/main/java/org/hyperledger/besu/nat/NatService.java

@@ -87,7 +87,10 @@ public class NatService {
       try {
         getNatManager().orElseThrow().start();
       } catch (Exception e) {
-        LOG.debug("Caught exception while trying to start the manager or service.", e);
+        LOG.debug(
+            "Nat manager failed to configure itself automatically due to the following reason "
+                + e.getMessage()
+                + ". NONE mode will be used");
         disableNatManager();
       }
     } else {
@@ -185,7 +188,6 @@ public class NatService {
 
   /** Disable the natManager */
   private void disableNatManager() {
-    LOG.warn("Unable to use NAT. Disabling NAT manager");
     currentNatMethod = NatMethod.NONE;
     currentNatManager = Optional.empty();
   }

nat/src/main/java/org/hyperledger/besu/nat/kubernetes/KubernetesNatManager.java

@@ -82,8 +82,7 @@ public class KubernetesNatManager extends AbstractNatManager {
               .orElseThrow(() -> new NatInitializationException("Service not found"));
       updateUsingBesuService(service);
     } catch (Exception e) {
-      throw new NatInitializationException(
-          "Failed update information using Kubernetes client SDK.", e);
+      throw new NatInitializationException(e.getMessage(), e);
     }
   }
 
@@ -134,7 +133,8 @@ public class KubernetesNatManager extends AbstractNatManager {
                 }
               });
     } catch (Exception e) {
-      throw new RuntimeException("Failed update information using pod metadata.", e);
+      throw new RuntimeException(
+          "Failed update information using pod metadata : " + e.getMessage(), e);
     }
   }