added statistics (#8)

added prometheus_async dependency

Pipfile

@@ -10,6 +10,7 @@ orjson = ">=3,<4"
 aiohttp = "*"
 asyncio-mqtt = "*"
 prometheus-client = "*"
+prometheus_async = "*"
 
 [dev-packages]
 pytest = "*"

barcode_server/barcode.py

@@ -8,7 +8,7 @@
 
 from barcode_server.config import AppConfig
 from barcode_server.keyevent_reader import KeyEventReader
-from barcode_server.stats import SCAN_COUNT, DEVICES_COUNT
+from barcode_server.stats import SCAN_COUNT, DEVICES_COUNT, DEVICE_DETECTION_TIME
 
 LOGGER = logging.getLogger(__name__)
 
@@ -99,6 +99,7 @@ def _detect_devices(self):
         DEVICES_COUNT.set(len(self.devices))
 
     @staticmethod
+    @DEVICE_DETECTION_TIME.time()
     def _find_devices(patterns: List, paths: List[str]) -> Dict[str, InputDevice]:
         """
         # Finds the input device with the name ".*Barcode Reader.*".

barcode_server/const.py

@@ -25,3 +25,5 @@
 CONFIG_NODE_PORT = "port"
 
 DEFAULT_SERVER_HOST = "localhost"
+
+ENDPOINT_DEVICES = "devices"

barcode_server/notifier/http.py

@@ -3,8 +3,10 @@
 
 import aiohttp
 from evdev import InputDevice
+from prometheus_async.aio import time
 
 from barcode_server.notifier import BarcodeNotifier
+from barcode_server.stats import HTTP_NOTIFIER_TIME
 from barcode_server.util import barcode_event_to_json
 
 LOGGER = logging.getLogger(__name__)
@@ -18,6 +20,7 @@ def __init__(self, method: str, url: str, headers: List[str]):
         headers = list(map(lambda x: tuple(x.split(':', 1)), headers))
         self.headers = list(map(lambda x: (x[0].strip(), x[1].strip()), headers))
 
+    @time(HTTP_NOTIFIER_TIME)
     async def notify(self, device: InputDevice, barcode: str):
         json = barcode_event_to_json(device, barcode)
         try:

barcode_server/notifier/mqtt.py

@@ -2,8 +2,10 @@
 
 from asyncio_mqtt import Client
 from evdev import InputDevice
+from prometheus_async.aio import time
 
 from barcode_server.notifier import BarcodeNotifier
+from barcode_server.stats import MQTT_NOTIFIER_TIME
 from barcode_server.util import barcode_event_to_json
 
 LOGGER = logging.getLogger(__name__)
@@ -25,6 +27,7 @@ def __init__(self, host: str, port: int = 1883,
         self.qos = qos
         self.retain = retain
 
+    @time(MQTT_NOTIFIER_TIME)
     async def notify(self, device: InputDevice, barcode: str):
         json = barcode_event_to_json(device, barcode)
         try:

barcode_server/stats.py

@@ -1,11 +1,28 @@
-from prometheus_client import Gauge
+from prometheus_client import Gauge, Summary
+
+from barcode_server.const import *
+
+WEBSOCKET_CLIENT_COUNT = Gauge(
+    'websocket_client_count',
+    'Number of currently connected websocket clients'
+)
 
 DEVICES_COUNT = Gauge(
     'devices_count',
-    'Number of devices currently detected'
+    'Number of currently detected devices'
 )
 
 SCAN_COUNT = Gauge(
     'scan_count',
     'Number of times a scan has been detected'
 )
+
+DEVICE_DETECTION_TIME = Summary('device_detection_processing_seconds', 'Time spent detecting devices')
+
+REST_TIME = Summary('rest_endpoint_processing_seconds', 'Time spent in a rest command handler', ['endpoint'])
+REST_TIME_DEVICES = REST_TIME.labels(endpoint=ENDPOINT_DEVICES)
+
+NOTIFIER_TIME = Summary('notifier_processing_seconds', 'Time spent in a notifier', ['type'])
+WEBSOCKET_NOTIFIER_TIME = NOTIFIER_TIME.labels(type='websocket')
+HTTP_NOTIFIER_TIME = NOTIFIER_TIME.labels(type='http')
+MQTT_NOTIFIER_TIME = NOTIFIER_TIME.labels(type='mqtt')

barcode_server/webserver.py

@@ -5,12 +5,14 @@
 from aiohttp import web
 from aiohttp.web_middlewares import middleware
 from evdev import InputDevice
+from prometheus_async.aio import time
 
 from barcode_server.barcode import BarcodeReader
 from barcode_server.config import AppConfig
-from barcode_server.const import X_Auth_Token
+from barcode_server.const import *
 from barcode_server.notifier.http import HttpNotifier
 from barcode_server.notifier.mqtt import MQTTNotifier
+from barcode_server.stats import REST_TIME_DEVICES, WEBSOCKET_CLIENT_COUNT, WEBSOCKET_NOTIFIER_TIME
 from barcode_server.util import barcode_event_to_json, input_device_to_dict
 
 LOGGER = logging.getLogger(__name__)
@@ -79,7 +81,8 @@ async def authentication_middleware(self, request, handler):
 
         return await handler(self, request)
 
-    @routes.get("/devices")
+    @routes.get(f"/{ENDPOINT_DEVICES}")
+    @time(REST_TIME_DEVICES)
     async def devices_handle(self, request):
         import orjson
         device_list = list(map(input_device_to_dict, self.barcode_reader.devices.values()))
@@ -92,7 +95,9 @@ async def websocket_handler(self, request):
         await websocket.prepare(request)
 
         self.clients.add(websocket)
-        LOGGER.debug(f"New client connected: {request.host} Client count: {len(self.clients)}")
+        client_count = len(self.clients)
+        WEBSOCKET_CLIENT_COUNT.set(client_count)
+        LOGGER.debug(f"New client connected: {request.host} Client count: {client_count}")
         try:
             async for msg in websocket:
                 if msg.type == aiohttp.WSMsgType.TEXT:
@@ -107,13 +112,18 @@ async def websocket_handler(self, request):
             LOGGER.exception(e)
         finally:
             self.clients.discard(websocket)
+            client_count = len(self.clients)
+            WEBSOCKET_CLIENT_COUNT.set(client_count)
             LOGGER.debug(f"Client disconnected: {request.host}")
         return websocket
 
     async def on_barcode(self, device: InputDevice, barcode: str):
         for notifier in self.notifiers:
             asyncio.create_task(notifier.notify(device, barcode))
+        await self._notify_websocket_clients(device, barcode)
 
+    @time(WEBSOCKET_NOTIFIER_TIME)
+    async def _notify_websocket_clients(self, device, barcode):
         for client in self.clients:
             json = barcode_event_to_json(device, barcode)
             asyncio.create_task(client.send_str(json))