config: use a validator for better configuration validation

inlet/kafka/config_test.go

@@ -6,6 +6,8 @@ package kafka
 import (
 	"testing"
 
+	"akvorado/common/helpers"
+
 	"github.com/Shopify/sarama"
 )
 
@@ -37,3 +39,9 @@ func TestCompressionCodecUnmarshal(t *testing.T) {
 		}
 	}
 }
+
+func TestDefaultConfiguration(t *testing.T) {
+	if err := helpers.Validate.Struct(DefaultConfiguration()); err != nil {
+		t.Fatalf("validate.Struct() error:\n%+v", err)
+	}
+}