Implement Prometheus metrics

src/bottle_plugins/prometheus_plugin.py

@@ -0,0 +1,53 @@
+import logging
+import os
+import urllib.parse
+
+from dtos import V1ResponseBase
+from metrics import start_metrics_http_server, REQUEST_COUNTER, REQUEST_DURATION
+
+PROMETHEUS_ENABLED = os.environ.get('PROMETHEUS_ENABLED', 'false').lower() == 'true'
+PROMETHEUS_PORT = int(os.environ.get('PROMETHEUS_PORT', 8192))
+
+
+def setup():
+    if PROMETHEUS_ENABLED:
+        start_metrics_http_server(PROMETHEUS_PORT)
+
+
+def prometheus_plugin(callback):
+    """
+    Bottle plugin to expose Prometheus metrics
+    http://bottlepy.org/docs/dev/plugindev.html
+    """
+    def wrapper(*args, **kwargs):
+        actual_response = callback(*args, **kwargs)
+
+        if PROMETHEUS_ENABLED:
+            try:
+                export_metrics(actual_response)
+            except Exception as e:
+                logging.warning("Error exporting metrics: " + str(e))
+
+        return actual_response
+
+    def export_metrics(actual_response):
+        res = V1ResponseBase(actual_response)
+
+        domain = "unknown"
+        if res.solution and res.solution.url:
+            parsed_url = urllib.parse.urlparse(res.solution.url)
+            domain = parsed_url.hostname
+
+        run_time = (res.endTimestamp - res.startTimestamp) / 1000
+        REQUEST_DURATION.labels(domain=domain).observe(run_time)
+
+        result = "unknown"
+        if res.message == "Challenge solved!":
+            result = "solved"
+        elif res.message == "Challenge not detected!":
+            result = "not_detected"
+        elif res.message.startswith("Error"):
+            result = "error"
+        REQUEST_COUNTER.labels(domain=domain, result=result).inc()
+
+    return wrapper