Introduce new gauge to help dasboard effectively show current rate li…

…mit applied for protocol

waku/common/rate_limit/service_metrics.nim

@@ -1,9 +1,19 @@
 {.push raises: [].}
 
-import metrics
+import std/options
+import metrics, setting
+
+declarePublicGauge waku_service_requests_limit,
+  "Applied rate limit of non-relay service", ["service"]
 
 declarePublicCounter waku_service_requests,
   "number of non-relay service requests received", ["service", "state"]
 
 declarePublicCounter waku_service_network_bytes,
   "total incoming traffic of specific waku services", labels = ["service", "direction"]
+
+proc setServiceLimitMetric*(service: string, limit: Option[RateLimitSetting]) =
+  if limit.isSome() and not limit.get().isUnlimited():
+    waku_service_requests_limit.set(
+      limit.get().calculateLimitPerSecond(), labelValues = [service]
+    )

waku/common/rate_limit/setting.nim

@@ -133,3 +133,8 @@ proc getSetting*(
 ): RateLimitSetting =
   let default = t.getOrDefault(GLOBAL, UnlimitedRateLimit)
   return t.getOrDefault(protocol, default)
+
+proc calculateLimitPerSecond*(setting: RateLimitSetting): float64 =
+  if setting.isUnlimited():
+    return 0.float64
+  return (setting.volume.float64 / setting.period.milliseconds.float64) * 1000.float64

waku/waku_filter_v2/protocol.nim

@@ -328,6 +328,7 @@ proc new*(
   )
 
   wf.initProtocolHandler()
+  setServiceLimitMetric(WakuFilterSubscribeCodec, rateLimitSetting)
   return wf
 
 const MaintainSubscriptionsInterval* = 1.minutes

waku/waku_lightpush/protocol.nim

@@ -110,4 +110,5 @@ proc new*(
     requestRateLimiter: newRequestRateLimiter(rateLimitSetting),
   )
   wl.initProtocolHandler()
+  setServiceLimitMetric(WakuLightpushCodec, rateLimitSetting)
   return wl

waku/waku_peer_exchange/protocol.nim

@@ -264,5 +264,6 @@ proc new*(
     requestRateLimiter: newRequestRateLimiter(rateLimitSetting),
   )
   wpx.initProtocolHandler()
+  setServiceLimitMetric(WakuPeerExchangeCodec, rateLimitSetting)
   asyncSpawn wpx.updatePxEnrCache()
   return wpx

waku/waku_store/protocol.nim

@@ -154,5 +154,5 @@ proc new*(
   )
 
   store.initProtocolHandler()
-
+  setServiceLimitMetric(WakuStoreCodec, rateLimitSetting)
   return store

waku/waku_store_legacy/protocol.nim

@@ -153,4 +153,5 @@ proc new*(
     requestRateLimiter: newRequestRateLimiter(rateLimitSetting),
   )
   ws.initProtocolHandler()
+  setServiceLimitMetric(WakuLegacyStoreCodec, rateLimitSetting)
   ws