add the ansible playbooks for the monitoring stack

ansible/roles/snmp_exporter/templates/snmp_exporter.service.j2

@@ -0,0 +1,25 @@
+[Unit]
+Description=SNMP Exporter for Prometheus
+Documentation=https://github.com/prometheus/snmp_exporter
+Wants=network-online.target
+After=network-online.target
+
+[Service]
+Type=simple
+User=monitoring
+Group=monitoring
+ExecStart=/usr/local/bin/snmp_exporter \
+  --config.file=/etc/snmp_exporter/snmp.yml \
+  --web.listen-address=0.0.0.0:9116 \
+  --log.level=info
+
+SyslogIdentifier=snmp_exporter
+Restart=always
+RestartSec=5
+
+NoNewPrivileges=true
+ProtectSystem=full
+ProtectHome=true
+
+[Install]
+WantedBy=multi-user.target