add exporter for uWSGI metrics (#54609)

debian/prometheus-entrouvert-exporter.install

@@ -1 +1,2 @@
 prometheus-entrouvert-exporter/prometheus-system-exporter.py usr/bin
+prometheus-entrouvert-exporter/prometheus-uwsgi-exporter.py usr/bin

debian/prometheus-entrouvert-exporter.prometheus-uwsgi-exporter.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=Collect uWSGI metrics
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/prometheus-uwsgi-exporter.py

debian/prometheus-entrouvert-exporter.prometheus-uwsgi-exporter.timer

@@ -0,0 +1,9 @@
+[Unit]
+Description=Run uWSGI metrics collection every minute
+
+[Timer]
+OnBootSec=0
+OnUnitActiveSec=1min
+
+[Install]
+WantedBy=timers.target

debian/rules

@@ -9,3 +9,4 @@ override_dh_auto_build:
 
 override_dh_installsystemd:
 	dh_installsystemd --name=prometheus-system-exporter
+	dh_installsystemd --name=prometheus-uwsgi-exporter

prometheus-entrouvert-exporter/prometheus-uwsgi-exporter.py

@@ -0,0 +1,87 @@
+#! /usr/bin/python3
+
+import collections
+import glob
+import json
+import os
+import socket
+import statistics
+
+from prometheus_client import CollectorRegistry, Gauge, write_to_textfile
+
+registry = CollectorRegistry()
+
+uwsgi_workers_rss_avg = Gauge(
+    'uwsgi_workers_rss_avg', 'Average RSS of uwsgi workers', ['app'], registry=registry
+)
+uwsgi_workers_rss_med = Gauge(
+    'uwsgi_workers_rss_med', 'Median RSS of uwsgi workers', ['app'], registry=registry
+)
+uwsgi_workers_rss_max = Gauge(
+    'uwsgi_workers_rss_max', 'Maximum RSS of uwsgi workers', ['app'], registry=registry
+)
+uwsgi_workers_vsz_avg = Gauge(
+    'uwsgi_workers_vsz_avg', 'Average VSZ of uwsgi workers', ['app'], registry=registry
+)
+uwsgi_workers_vsz_med = Gauge(
+    'uwsgi_workers_vsz_med', 'Median VSZ of uwsgi workers', ['app'], registry=registry
+)
+uwsgi_workers_vsz_max = Gauge(
+    'uwsgi_workers_vsz_max', 'Maximum VSZ of uwsgi workers', ['app'], registry=registry
+)
+uwsgi_workers_status = Gauge(
+    'uwsgi_workers_status', 'uwsgi workers status', ['app', 'status'], registry=registry
+)
+
+
+app_name = None
+
+for stats_sock in glob.glob('/run/*/stats.sock'):
+    app_name = stats_sock.split('/')[2]
+    app_name = app_name.replace('authentic2-multitenant', 'authentic')
+    stats_json = ''
+    with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as s:
+        s.connect(stats_sock)
+        while True:
+            data = s.recv(4096)
+            if not data:
+                break
+            stats_json += data.decode('utf8', 'ignore')
+    stats_data = json.loads(stats_json)
+
+    listen_queue = stats_data['listen_queue']
+    workers_rss = []
+    workers_vsz = []
+    workers_status = collections.defaultdict(int)
+    workers_status['idle'] = 0
+    workers_status['busy'] = 0
+    for worker in stats_data['workers']:
+        if worker['status'] == 'cheap':
+            continue
+        workers_status[worker['status']] += 1
+        workers_rss.append(worker['rss'])
+        workers_vsz.append(worker['vsz'])
+
+    uwsgi_workers_rss_max.labels(app=app_name).set(max(workers_rss))
+    uwsgi_workers_rss_avg.labels(app=app_name).set(statistics.mean(workers_rss))
+    uwsgi_workers_rss_med.labels(app=app_name).set(statistics.median(workers_rss))
+    uwsgi_workers_vsz_max.labels(app=app_name).set(max(workers_vsz))
+    uwsgi_workers_vsz_avg.labels(app=app_name).set(statistics.mean(workers_vsz))
+    uwsgi_workers_vsz_med.labels(app=app_name).set(statistics.median(workers_vsz))
+    for k in workers_status:
+        uwsgi_workers_status.labels(app=app_name, status=k).set(workers_status[k])
+
+if app_name:
+    write_to_textfile('/var/lib/prometheus/node-exporter/uwsgi.prom', registry)
+else:
+    # host for containers?
+    content = ''
+    for machine_stat in glob.glob('/var/lib/machines/*/var/lib/prometheus/node-exporter/uwsgi.prom'):
+        with open(machine_stat) as fd:
+            content += fd.read()
+    if content:
+        with open('/var/lib/prometheus/node-exporter/uwsgi.prom.tmp', 'w') as fd:
+            fd.write(content)
+        os.rename(
+            '/var/lib/prometheus/node-exporter/uwsgi.prom.tmp', '/var/lib/prometheus/node-exporter/uwsgi.prom'
+        )