Add prometheus-memcached-exporter

Extend the memcached service for the AUR to allow the memcached group to
read the socket to obtain statistics.

group_vars/all/common.yml

@@ -13,3 +13,4 @@ maintenance_remote_machine: "{{ hostvars[inventory_hostname]['ansible_env'].SSH_
 
 # prometheus-node-exporter port
 prometheus_exporter_port: '9100'
+prometheus_memcached_exporter_port: '9150'

host_vars/aur-dev.archlinux.org

 ---
 filesystem: btrfs
+memcached_socket: "/var/run/aurweb.sock"
+
 zabbix_agent_templates:
   - Template OS Linux
   - Template App Borg Backup

host_vars/aur.archlinux.org

 ---
 filesystem: btrfs
+memcached_socket: "/var/run/aurweb.sock"
+
 zabbix_agent_templates:
   - Template OS Linux
   - Template App Borg Backup

hosts

@@ -31,7 +31,6 @@ bbs.archlinux.org
 homedir.archlinux.org
 bugs.archlinux.org
 aur.archlinux.org
-aur-dev.archlinux.org
 gitlab.archlinux.org
 accounts.archlinux.org
 gemini.archlinux.org
@@ -84,7 +83,6 @@ repro3.pkgbuild.com
 reproducible.archlinux.org
 
 [memcached]
-apollo.archlinux.org
 aur.archlinux.org
 aur-dev.archlinux.org
 

roles/aurweb/templates/aurweb-memcached.service.j2

@@ -5,7 +5,7 @@ After=network.target
 [Service]
 User={{ aurweb_user }}
 Group=memcached
-ExecStart=/usr/bin/memcached -s {{ aurweb_memcached_socket }} -m {{ aurweb_memcached_memory }} -o modern
+ExecStart=/usr/bin/memcached -s {{ aurweb_memcached_socket }} -m {{ aurweb_memcached_memory }} -o modern -a 770
 Restart=always
 NoNewPrivileges=yes
 PrivateTmp=yes

roles/prometheus/templates/prometheus.yml.j2

@@ -61,6 +61,16 @@ scrape_configs:
       labels:
         instance: "aur.archlinux.org"
 
+  - job_name: 'memcached_exporter'
+    static_configs:
+    {% for host in groups['memcached'] %}
+
+    - targets: ['{{ host }}:{{ prometheus_memcached_exporter_port }}']
+      labels:
+        instance: "{{ host }}"
+
+    {% endfor %}
+
   - job_name: 'blackbox'
     metrics_path: /probe
     scrape_interval: 15s

roles/prometheus_exporters/tasks/main.yml

@@ -44,6 +44,10 @@
   systemd: name=prometheus-mysqld-exporter enabled=yes daemon_reload=yes state=started
   when: "'mysql_servers' in group_names"
 
+- name: copy prometheus memcached exporter configuration
+  template: src=prometheus-memcached-exporter.j2 dest=/etc/conf.d/prometheus-memcached-exporter owner=root group=root mode=600
+  when: "'memcached' in group_names"
+
 - name: install node exporter configuration
   template: src=prometheus-node-exporter.env.j2 dest=/etc/conf.d/prometheus-node-exporter owner=root group=root mode=600
 
@@ -119,3 +123,8 @@
   firewalld: state=enabled permanent=true immediate=yes
         rich_rule="rule family=ipv4 source address={{ hostvars['monitoring.archlinux.org']['ipv4_address'] }} port protocol=tcp port={{ prometheus_mysqld_exporter_port }} accept"
   when: "'mysql_servers' in group_names"
+
+- name: open prometheus memcached exporter ipv4 port for monitoring.archlinux.org
+  firewalld: state=enabled permanent=true immediate=yes
+        rich_rule="rule family=ipv4 source address={{ hostvars['monitoring.archlinux.org']['ipv4_address'] }} port protocol=tcp port={{ prometheus_memcached_exporter_port }} accept"
+  when: "'memcached' in group_names"