add monitoring metrics

.luacheckrc

@@ -11,5 +11,8 @@ read_globals = {
 	-- Minetest
 	"vector", "ItemStack",
 	"dump", "dump2",
-	"VoxelArea"
+	"VoxelArea",
+
+	-- deps
+	"monitoring"
 }

bridge_rx.lua

@@ -1,5 +1,10 @@
 local http = ...
 
+local metric
+if minetest.get_modpath("monitoring") then
+    metric = monitoring.counter("mtui_rx", "number of received commands")
+end
+
 local command_handlers = {}
 
 function mtui.register_on_command(type, handler)
@@ -20,6 +25,9 @@ local function fetch_commands()
             local command_list = minetest.parse_json(res.data)
 
             for _, cmd in ipairs(command_list) do
+                if metric then
+                    metric.inc()
+                end
                 local handler = command_handlers[cmd.type]
                 if type(handler) == "function" then
                     local send = function(data)

bridge_tx.lua

@@ -1,5 +1,10 @@
 local http = ...
 
+local metric
+if minetest.get_modpath("monitoring") then
+    metric = monitoring.counter("mtui_tx", "number of sent commands")
+end
+
 -- list of commands to send
 local commands = {}
 
@@ -30,6 +35,7 @@ end
 
 -- queues a command to send to the ui
 function mtui.send_command(cmd)
+    metric.inc()
     table.insert(commands, cmd)
 
     if not send_triggered then

mod.conf

@@ -1,2 +1,2 @@
 name = mtui
-optional_depends = mail
+optional_depends = mail, monitoring