tools - traffic_ctl, traffic_layout: use ArgParse groups to handle mutually exclusive options. (#12623)

* tools -  traffic_ctl, traffic_layout: use ArgParse groups to handle
mutually exclusive options.

traffic_ctl:

Usage: traffic_ctl [OPTIONS] CMD [ARGS ...]

Commands ---------------------- Description -----------------------
drain                           Drain the requests

Options ======================= Default ===== Description =============

Group (drain_mode)
  -N, --no-new-connection                     Wait for new connections down to threshold before starting draining
  -U, --undo                                  Recover server from the drain mode

traffic_layout:

Usage: traffic_layout CMD [OPTIONS]

Commands ---------------------- Description -----------------------
info                            Show the layout as default

Options ======================= Default ===== Description =============
-j, --json                                    Produce output in JSON format (when supported)

Group (display_mode)
  --features                                  Show the compiled features
  --versions                                  Show various library and other versioning information

Author: brbzull0

src/traffic_ctl/traffic_ctl.cc

@@ -183,11 +183,15 @@ main([[maybe_unused]] int argc, const char **argv)
   // server commands
   server_command.add_command("backtrace", "Show a full stack trace of the traffic_server process",
                              [&]() { CtrlUnimplementedCommand("backtrace"); });
-  server_command.add_command("status", "Show the proxy status", Command_Execute).add_example_usage("traffic_ctl server status");
-  server_command.add_command("drain", "Drain the requests", Command_Execute)
-    .add_example_usage("traffic_ctl server drain [OPTIONS]")
-    .add_option("--no-new-connection", "-N", "Wait for new connections down to threshold before starting draining")
-    .add_option("--undo", "-U", "Recover server from the drain mode");
+  server_command.add_command("status", "Show the proxy status", [&]() { command->execute(); })
+    .add_example_usage("traffic_ctl server status");
+  auto &drain_cmd = server_command.add_command("drain", "Drain the requests", [&]() { command->execute(); });
+  drain_cmd.add_example_usage("traffic_ctl server drain [OPTIONS]");
+
+  drain_cmd.add_mutex_group("drain_mode", false, "Drain mode options");
+  drain_cmd.add_option_to_group("drain_mode", "--no-new-connection", "-N",
+                                "Wait for new connections down to threshold before starting draining");
+  drain_cmd.add_option_to_group("drain_mode", "--undo", "-U", "Recover server from the drain mode");
 
   auto &debug_command =
     server_command.add_command("debug", "Enable/Disable ATS for diagnostic messages at runtime").require_commands();

src/traffic_layout/traffic_layout.cc

@@ -45,11 +45,12 @@ main([[maybe_unused]] int argc, const char **argv)
     .add_option("--version", "-V", "Print version string");
 
   // info command
-  engine.parser.add_command("info", "Show the layout as default", [&]() { engine.info(); })
-    .add_option("--features", "", "Show the compiled features")
-    .add_option("--versions", "", "Show various library and other versioning information")
-    .add_option("--json", "-j", "Produce output in JSON format (when supported)")
-    .set_default();
+  auto &info_cmd = engine.parser.add_command("info", "Show the layout as default", [&]() { engine.info(); });
+  info_cmd.add_mutex_group("display_mode", false, "Display mode options");
+  info_cmd.add_option_to_group("display_mode", "--features", "", "Show the compiled features");
+  info_cmd.add_option_to_group("display_mode", "--versions", "", "Show various library and other versioning information");
+
+  info_cmd.add_option("--json", "-j", "Produce output in JSON format (when supported)").set_default();
   // init command
   engine.parser.add_command("init", "Initialize(create) the runroot sandbox", [&]() { engine.create_runroot(); })
     .add_option("--absolute", "-a", "Produce absolute path in the runroot.yaml")