main: Hide log messages by default when using json output mode

Signed-off-by: Andre Detsch <[email protected]>

src/main.cc

@@ -228,7 +228,7 @@ bpo::variables_map parse_options(int argc, char** argv) {
 #endif
       ("interval", bpo::value<uint64_t>(), "Override uptane.polling_secs interval to poll for update when in daemon mode.")
       ("command", bpo::value<std::string>(), subs.c_str())
-      ("json", bpo::value<bool>(), "Output targets information as json ('check' and 'list' commands only)");
+      ("json", bpo::value<bool>(), "Output targets information as json ('check' and 'list' commands only).");
   // clang-format on
 
   // consider the first positional argument as the aktualizr run mode
@@ -280,6 +280,13 @@ int main(int argc, char* argv[]) {
 
   int ret_val = EXIT_FAILURE;
   try {
+    // When enabling json output mode, hide log messages by default
+    if (commandline_map.count("json") > 0 && commandline_map.at("json").as<bool>() &&
+        commandline_map.count("loglevel") == 0) {
+      commandline_map.insert(std::pair<std::string, boost::program_options::variable_value>(
+          "loglevel", boost::program_options::variable_value(static_cast<int>(boost::log::trivial::fatal), false)));
+    }
+
     Config config(commandline_map);
 
     if (geteuid() != 0) {