prometheus-node-exporter-lua: fix bss identifier in hostapd_stations

We previously did not identify the correct BSS from the output of
`hostapd_cli -i <phy> status`, because when asked for a vif it will
always respond with information relevant to the whole phy.

The per vif settings will use an iterator and we now try to detect
the correct BSS from that output.

Signed-off-by: Martin Weinelt <hexa@darmstadt.ccc.de>

utils/prometheus-node-exporter-lua/Makefile

@@ -4,7 +4,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=prometheus-node-exporter-lua
-PKG_VERSION:=2021.07.04
+PKG_VERSION:=2021.07.24
 PKG_RELEASE:=1
 
 PKG_MAINTAINER:=Etienne CHAMPETIER <champetier.etienne@gmail.com>

utils/prometheus-node-exporter-lua/files/usr/lib/lua/prometheus-collectors/hostapd_stations.lua

@@ -16,23 +16,29 @@ local function get_wifi_interface_labels()
       handle:close()
 
       local hostapd = {}
+      local bss_idx = -1
       for line in hostapd_status:gmatch("[^\r\n]+") do
         local name, value = string.match(line, "(.+)=(.+)")
-        if name == "phy" then
-          hostapd["vif"] = value
         elseif name == "freq" then
           hostapd["freq"] = value
         elseif name == "channel" then
           hostapd["channel"] = value
-        elseif name == "bssid[0]" then
-          hostapd["bssid"] = value
-        elseif name == "ssid[0]" then
-          hostapd["ssid"] = value
+        -- hostapd gives us all bss on the relevant phy, find the one we're interested in
+        elseif string.match(name, "bss%[%d%]") then
+          if value == cfg['ifname'] then
+            bss_idx = tonumber(string.match(name, "bss%[(%d)%]"))
+          end
+        elseif bss_idx >= 0 then
+          if name == "bssid[" .. bss_idx .. "]" then
+            hostapd["bssid"] = value
+          elseif name == "ssid[" .. bss_idx .. "]" then
+            hostapd["ssid"] = value
+          end
         end
       end
 
       local labels = {
-        vif = hostapd['vif'],
+        vif = cfg['ifname'],
         ssid = hostapd['ssid'],
         bssid = hostapd['bssid'],
         encryption = cfg['encryption'], -- In a mixed scenario it would be good to know if A or B was used