mysql: new munin graph to follow binlog_days over time

CHANGELOG.md

@@ -31,6 +31,7 @@ The **patch** part changes is incremented if multiple releases happen the same m
 * fail2ban: add `fail2ban_sshd_port` variable to configure sshd port
 * kvm-host: release 23.09.1 for migrate-vm.sh
 * metricbeat/logstash: fix Ansible syntax
+* mysql: new munin graph to follow binlog_days over time
 * nagios-nrpe: add a NRPE check-local command with completion.
 * nagios-nrpe: add a proper monitoring plugin for GlusterFS (on servers, not for clients)
 * php: add new variable to disable overriding settings of php-fpm default pool (www)

mysql/files/mysql_binlog_days

@@ -0,0 +1,44 @@
+#!/bin/sh
+
+output_config() {
+    echo "graph_title MySQL - Value of expire_logs_days variable"
+    echo "graph_category mysql"
+    echo "binlogdays.label Number of days of storage of binary logs"
+    echo "binlogdays.draw AREA"
+    echo 'graph_args -l 0'
+    echo 'graph_scale no'    
+}
+
+output_values() {
+    printf "binlogdays.value %d\n" $(binlog_days)
+}
+
+binlog_days() {
+    mysql --skip-column-names --silent --execute "show variables like 'expire_logs_days';" | awk '{print $2}'
+}
+
+output_usage() {
+    printf >&2 "%s - munin plugin to graph value of MySQL expire_logs_days system variable\n" ${0##*/}
+    printf >&2 "Usage: %s [config]\n" ${0##*/}
+}
+
+case $# in
+    0)
+        output_values
+        ;;
+    1)
+        case $1 in
+            config)
+                output_config
+                ;;
+            *)
+                output_usage
+                exit 1
+                ;;
+        esac
+        ;;
+    *)
+        output_usage
+        exit 1
+        ;;
+esac

mysql/tasks/munin.yml

@@ -66,6 +66,15 @@
       - replication
     notify: restart munin-node
 
+  - name: Install custom plugin for binlog retention tracking
+    ansible.builtin.copy:
+      src: mysql_binlog_days
+      dest: /etc/munin/plugins/mysql_binlog_days
+      owner: root
+      group: root
+      mode: "0755"
+    notify: restart munin-node
+
   - name: verify Munin configuration for mysql < Debian 11
     ansible.builtin.replace:
       dest: /etc/munin/plugin-conf.d/munin-node