Add prometheus metrics endpoint. Closes #67

server/webserver.py

@@ -6,9 +6,11 @@ from threading import Thread
 import bottle
 import pytz
 from bottle import run, request, response, template
+from prometheus_client import CONTENT_TYPE_LATEST, generate_latest
 
 from core.config import MAX_SPOT_AGE, ALLOW_SPOTTING
 from core.constants import BANDS, ALL_MODES, MODE_TYPES, SIGS, CONTINENTS, SOFTWARE_VERSION
+from core.prometheus_metrics_handler import page_requests_counter, registry, get_metrics, api_requests_counter
 from data.spot import Spot
 
 
@@ -19,6 +21,8 @@ class WebServer:
     def __init__(self, spots, alerts, status_data, port):
         self.last_page_access_time = None
         self.last_api_access_time = None
+        self.page_access_counter = 0
+        self.api_access_counter = 0
         self.spots = spots
         self.alerts = alerts
         self.status_data = status_data
@@ -44,6 +48,8 @@ class WebServer:
         bottle.get("/status")(lambda: self.serve_template('webpage_status'))
         bottle.get("/about")(lambda: self.serve_template('webpage_about'))
         bottle.get("/apidocs")(lambda: self.serve_template('webpage_apidocs'))
+        # Route for Prometheus metrics
+        bottle.get("/metrics")(lambda: self.serve_prometheus_metrics())
         # Default route to serve from "webassets"
         bottle.get("/<filepath:path>")(self.serve_static_file)
 
@@ -92,6 +98,8 @@ class WebServer:
     # Serve a JSON API endpoint
     def serve_api(self, data):
         self.last_api_access_time = datetime.now(pytz.UTC)
+        self.api_access_counter += 1
+        api_requests_counter.inc()
         self.status = "OK"
         response.content_type = 'application/json'
         response.set_header('Cache-Control', 'no-store')
@@ -100,6 +108,8 @@ class WebServer:
     # Accept a spot
     def accept_spot(self):
         self.last_api_access_time = datetime.now(pytz.UTC)
+        self.api_access_counter += 1
+        api_requests_counter.inc()
         self.status = "OK"
 
         try:
@@ -153,6 +163,8 @@ class WebServer:
     # Serve a templated page
     def serve_template(self, template_name):
         self.last_page_access_time = datetime.now(pytz.UTC)
+        self.page_access_counter += 1
+        page_requests_counter.inc()
         self.status = "OK"
         return template(template_name)
 
@@ -160,6 +172,10 @@ class WebServer:
     def serve_static_file(self, filepath):
         return bottle.static_file(filepath, root="webassets")
 
+    # Serve Prometheus metrics
+    def serve_prometheus_metrics(self):
+        return get_metrics()
+
     # Utility method to apply filters to the overall spot list and return only a subset. Enables query parameters in
     # the main "spots" GET call.
     def get_spot_list_with_filters(self):