Prometheus metrics for Dovecot

handlers/main.yml

@@ -1,6 +1,13 @@
 - name: restart dovecot
   service: name=dovecot state=restarted
 
+- name: restart prometheus-dovecot-master-exporter
+  ansible.builtin.systemd_service:
+    name: prometheus-dovecot-master-exporter
+    state: restarted
+    enabled: true
+    daemon_reload: true
+
 - name: restart postfix
   service: name=postfix state=restarted
 

tasks/main.yml

@@ -127,6 +127,20 @@
   ansible.builtin.shell: "sievec '{{ item.dest }}'"
   loop: "{{ mailserver_sieve_scripts.results }}"
 
+- name: copy prometheus-dovecot-master-exporter
+  ansible.builtin.template:
+    src:  "{{ item.src }}"
+    dest: "{{ item.dest }}"
+    mode: "{{ item.mode }}"
+  loop:
+  - src: dovecot/prometheus-dovecot-master-exporter.j2
+    dest: /usr/local/sbin/prometheus-dovecot-master-exporter
+    mode: "0755"
+  - src: dovecot/prometheus-dovecot-master-exporter.service.j2
+    dest: /etc/systemd/system/prometheus-dovecot-master-exporter.service
+    mode: "0644"
+  notify: restart prometheus-dovecot-master-exporter
+
 # prometheus-postfix-exporter
 - name: configure prometheus postfix exporter
   ansible.builtin.template:

templates/dovecot/dovecot.conf.j2

@@ -136,6 +136,7 @@ service quota-status {
   client_limit = 1
 }
 
+# Metrics
 service stats {
   unix_listener stats-reader {
     user = vmail
@@ -149,6 +150,31 @@ service stats {
     # 0666 instead of 0660, so postfixadmin can call doveadm pw without errors
     mode = 0666
   }
+
+  inet_listener http {
+    port = 9900
+  }
+}
+
+metric auths {
+  filter = event=auth_request_finished
+}
+metric auth_successes {
+  filter = event=auth_request_finished AND success=yes
+}
+
+metric imap_commands {
+  filter = event=imap_command_finished
+  group_by = cmd_name tagged_reply_state duration:exponential:1:9:10
+}
+
+metric sieve_actions {
+  filter = event=sieve_action_finished
+  group_by = action_name
+}
+
+metric mail_deliveries {
+  filter = event=mail_delivery_finished
 }
 
 # Postfix delivers incoming mails via lda (transport "dovecot")

templates/dovecot/prometheus-dovecot-master-exporter.j2

@@ -0,0 +1,47 @@
+#!/usr/bin/python3
+import time
+import subprocess
+import json
+from prometheus_client import start_http_server, PROCESS_COLLECTOR, PLATFORM_COLLECTOR, GC_COLLECTOR
+from prometheus_client.core import GaugeMetricFamily, CounterMetricFamily, REGISTRY
+from prometheus_client.registry import Collector
+
+class CustomCollector(Collector):
+    def collect(self):
+        service_status = json.loads(subprocess.run(['doveadm', '-f', 'json', 'service', 'status'], check=True, capture_output=True).stdout.decode())
+        process_status = json.loads(subprocess.run(['doveadm', '-f', 'json', 'process', 'status'], check=True, capture_output=True).stdout.decode())
+        dovecot_processes_count = GaugeMetricFamily('dovecot_processes_count', 'Number of running processes per service', labels=['service'])
+        dovecot_processes_total = CounterMetricFamily('dovecot_processes_total', 'Total count of started processes per service', labels=['service'])
+        dovecot_processes_limit = GaugeMetricFamily('dovecot_processes_limit', 'Process limit per service', labels=['service'])
+        dovecot_clients_count = GaugeMetricFamily('dovecot_clients_count', 'Number of connected clients per service', labels=['service'])
+        dovecot_clients_total = CounterMetricFamily('dovecot_clients_total', 'Total count of clients per service', labels=['service'])
+        dovecot_clients_per_process_limit = GaugeMetricFamily('dovecot_clients_per_process_limit', 'Client limit per process', labels=['service'])
+        for line in service_status:
+          dovecot_processes_count.add_metric([line['name']], int(line['process_count']))
+          dovecot_processes_total.add_metric([line['name']], int(line['process_total']))
+          dovecot_processes_limit.add_metric([line['name']], int(line['process_limit']))
+          dovecot_clients_count.add_metric(
+            [line['name']],
+            sum(int(line['client_limit'])-int(proc['available_count']) for proc in process_status if proc['name'] == line['name'])
+          )
+          dovecot_clients_total.add_metric(
+            [line['name']],
+            sum(int(proc['total_count']) for proc in process_status if proc['name'] == line['name'])
+          )
+          dovecot_clients_per_process_limit.add_metric([line['name']], int(line['client_limit']))
+        yield dovecot_processes_count
+        yield dovecot_processes_total
+        yield dovecot_processes_limit
+        yield dovecot_clients_count
+        yield dovecot_clients_total
+        yield dovecot_clients_per_process_limit
+
+REGISTRY.unregister(PROCESS_COLLECTOR)
+REGISTRY.unregister(PLATFORM_COLLECTOR)
+REGISTRY.unregister(GC_COLLECTOR)
+REGISTRY.register(CustomCollector())
+
+if __name__ == '__main__':
+  start_http_server(addr='127.0.0.1', port=9162)
+  while True:
+    time.sleep(100)

templates/dovecot/prometheus-dovecot-master-exporter.service.j2

@@ -0,0 +1,12 @@
+[Unit]
+Description=Dovecot master prometheus exporter
+After=dovecot.service
+Requisite=dovecot.service
+
+[Install]
+WantedBy=multi-user.target
+
+[Service]
+ExecStart=/usr/bin/python3 /usr/local/sbin/prometheus-dovecot-master-exporter
+Environment=PYTHONUNBUFFERED=1
+Restart=always