Add prometheus metrics endpoint. Closes #67

core/prometheus_metrics_handler.py

@@ -0,0 +1,40 @@
+from bottle import response
+from prometheus_client import CollectorRegistry, generate_latest, CONTENT_TYPE_LATEST, Counter, disable_created_metrics, \
+    Gauge
+
+disable_created_metrics()
+# Prometheus metrics registry
+registry = CollectorRegistry()
+
+page_requests_counter = Counter(
+    "page_requests",
+    "Total number of page requests received",
+    registry=registry,
+)
+api_requests_counter = Counter(
+    "api_requests",
+    "Total number of API requests received",
+    registry=registry
+)
+spots_gauge = Gauge(
+    "spots",
+    "Number of spots currently in the software",
+    registry=registry
+)
+alerts_gauge = Gauge(
+    "alerts",
+    "Number of alerts currently in the software",
+    registry=registry
+)
+memory_use_gauge = Gauge(
+    "memory_usage_bytes",
+    "Current memory usage of the software in bytes",
+    registry=registry
+)
+
+
+# Get a Prometheus metrics response for Bottle
+def get_metrics():
+    response.content_type = CONTENT_TYPE_LATEST
+    response.status = 200
+    return generate_latest(registry)

core/status_reporter.py

@@ -7,6 +7,7 @@ import pytz
 
 from core.config import SERVER_OWNER_CALLSIGN
 from core.constants import SOFTWARE_VERSION
+from core.prometheus_metrics_handler import memory_use_gauge, spots_gauge, alerts_gauge
 
 
 # Provides a timed update of the application's status data.
@@ -60,8 +61,15 @@ class StatusReporter:
         self.status_data["webserver"] = {"status": self.web_server.status,
                                          "last_api_access": self.web_server.last_api_access_time.replace(
                                              tzinfo=pytz.UTC).timestamp() if self.web_server.last_api_access_time else 0,
+                                         "api_access_count": self.web_server.api_access_counter,
                                          "last_page_access": self.web_server.last_page_access_time.replace(
-                                             tzinfo=pytz.UTC).timestamp() if self.web_server.last_page_access_time else 0}
+                                             tzinfo=pytz.UTC).timestamp() if self.web_server.last_page_access_time else 0,
+                                         "page_access_count": self.web_server.page_access_counter}
+
+        # Update Prometheus metrics
+        memory_use_gauge.set(psutil.Process(os.getpid()).memory_info().rss * 1024)
+        spots_gauge.set(len(self.spots))
+        alerts_gauge.set(len(self.alerts))
 
         self.run_timer = Timer(self.run_interval, self.run)
         self.run_timer.start()