zabbix-agent: add memcached monitoring

host_vars/apollo.archlinux.org

@@ -32,6 +32,7 @@ zabbix_agent_templates:
   - Template App SSH Service
   - Template App Zabbix Server
   - Template App PostgreSQL
+  - Template App Memcached
 
 zabbix_agent_host_groups:
   - Linux servers

hosts

@@ -57,3 +57,6 @@ runner2.archlinux.org
 [reproduciblebuilds]
 repro1.pkgbuild.com
 repro2.pkgbuild.com
+
+[memcached]
+apollo.archlinux.org

roles/zabbix-agent/files/memcached-stats.py

+#!/usr/bin/python
+
+'''
+Metrics:
+
+- uptime - time memcached is alive
+- listen_disabled_num - the number of times: the max number of connections is reachedand:ii
+- conn_yields -  Number of times a client connection was throttled.
+- hits - get_hits / cmd_get. It indicates how efficient your Memcached server is.
+- fill - used bytes / limit_maxbytes - Fill percentage
+- evictions - an eviction is when an item that still has time to live is removed from the cache because a brand new item needs to be allocated
+- command flush - the flush_all command invalidates all items in the database
+- connections_total - total number of connections
+'''
+
+import argparse
+import json
+import os
+
+from memcache import Client
+
+
+SOCKET_DIR = '/run/memcached'
+
+
+def stats(socket):
+    client = Client([f'unix://{SOCKET_DIR}/{socket}'])
+    stats = client.get_stats()
+    if not stats:
+        print(json.dumps({}))
+    else:
+        print(json.dumps(stats[0][1]))
+
+
+def discover():
+    sockets = []
+    for loc in os.listdir(SOCKET_DIR):
+        if not loc.endswith('.sock'):
+            continue
+        sockets.append({"{#SOCKET}": loc})
+
+    print(json.dumps({"data": sockets}))
+
+
+def main():
+    parser = argparse.ArgumentParser(description='memcached statistics dumptool (in json)')
+    parser.add_argument('--discover', action='store_true', help='discover memcached sockets')
+    parser.add_argument('--socket', type=str, help='the memcached socket location')
+    args = parser.parse_args()
+    if args.discover:
+        discover()
+    if args.socket:
+        stats(args.socket)
+
+
+if __name__ == "__main__":
+    main()

roles/zabbix-agent/tasks/main.yml

@@ -25,6 +25,17 @@
   pacman: name=perl-dbi,perl-dbd-pg,perl-json
   when: "'postgresql-servers' in group_names"
 
+- name: install memcached monitoring packages
+  pacman: name=python-memcached
+  when: "'memcached' in group_names"
+
+- name: adding existing zabbix-agent to memcached group
+  user:
+    name: zabbix-agent
+    groups: memcached
+    append: yes
+  when: "'memcached' in group_names"
+
 - file: path=/etc/zabbix state=directory owner=root group=root mode=755
 
 - name: create host PSK
@@ -83,6 +94,7 @@
     - mysql-dbsize-stats.pl
     - postgresql-dbsize-stats.pl
     - postgresql-user-stats.pl
+    - memcached-stats.py
 
 - name: Install helper scripts
   copy: src=nginx-zabbix.pl dest=/usr/local/bin/nginx-zabbix.pl mode=0755 owner=root group=root

roles/zabbix-agent/templates/zabbix-agent-sudoers.conf.j2

-zabbix-agent ALL=(root) NOPASSWD: /usr/local/bin/borg list --json --format {start}{end} --sort-by timestamp --last 1, /usr/local/bin/mysql-dbsize-stats.pl
+zabbix-agent ALL=(root) NOPASSWD: /usr/local/bin/borg list --json --format {start}{end} --sort-by timestamp --last 1, /usr/local/bin/mysql-dbsize-stats.pl, /usr/local/bin/memcached-stats.py
 zabbix-agent ALL=(postgres) NOPASSWD: /usr/local/bin/postgresql-dbsize-stats.pl, /usr/local/bin/postgresql-user-stats.pl

roles/zabbix-agent/templates/zabbix_agentd.conf

@@ -63,3 +63,7 @@ UserParameter=linux.pressure,perl -MJSON -E 'my %h; for my $filename (@ARGV) {op
 UserParameter=arch_audit.data,arch-audit -u | grep -v "from testing repos"
 
 UserParameter=arch_archive.db_count,echo 'select count(*) from files;' | sqlite3 /home/archive/archive-uploader.sqlite
+
+UserParameter=memcached.stats[*],sudo /usr/local/bin/memcached-stats.py --socket '$1'
+UserParameter=memcached.stats_discover,/usr/local/bin/memcached-stats.py --discover
+#UserParameter=postgresql.dbsize_discover,sudo -u postgres /usr/local/bin/postgresql-dbsize-stats.pl discover