feat(oam): codify garage-pdu-relay snmpd extend + timeout hardening [#733]

Deployed manually on tsys-librenms 2026-09-02 (founder relay ruling); codified same-day rule. snmpget -t2 -r1 so a dark PDU answers in ~2s. Deployed target: tsys-librenms:/usr/local/bin/garage-pdu-relay. Detail: https://projects.knownelement.com/issues/733
2026-09-03 12:55:31 -05:00
parent d3b9099d5f
commit e27e3a06b8
2 changed files with 99 additions and 0 deletions
@@ -0,0 +1,30 @@
+#!/bin/bash
+# garage-pdu-relay: expose APC AP7830 metered output current via snmpd extend.
+#
+# Relay pattern (founder ruling 2026-09-02): the garage PDU speaks SNMPv1
+# only, walks die on its old AOS, and its ACL admits the LibreNMS VM vantage.
+# This relay runs ON tsys-librenms; HA polls the relay via the fleet snmpd
+# extend (same rails as drac-extend). Output: "output_amps <x.y>".
+#
+# Deploy target: tsys-librenms:/usr/local/bin/garage-pdu-relay ONLY (relay
+# host — not a per-host agent). snmpd.conf line on the relay host:
+#   extend garagepdu /usr/local/bin/garage-pdu-relay
+# snmpd ACL must admit the pfv-bms LAN + Tailscale IPs as query sources
+# (rocommunity kn3lmgmt 192.168.3.12 / 100.67.108.125 as of 2026-09-03).
+#
+# Codified 2026-09-03 [#733]: was deployed manually 2026-09-02; hardened
+# with explicit snmpget timeout/retry so a dark PDU answers in ~2s instead
+# of ~6s and cannot pile up long-running children under HA's poll cadence.
+set -euo pipefail
+
+PDU_HOST="${PDU_HOST:-pfv-garage-pdu-1.knel.net}"
+COMMUNITY="${PDU_COMMUNITY:-kn3lmgmt}"
+OID=".1.3.6.1.4.1.318.1.1.12.2.3.1.1.2.1"
+
+raw=$(snmpget -v1 -c "$COMMUNITY" -t 2 -r 1 -On -Ov "$PDU_HOST" "$OID" 2>/dev/null \
+    | grep -oE '[0-9]+$') || true
+if [ -z "${raw:-}" ]; then
+    echo "output_amps unavailable"
+    exit 0
+fi
+awk -v t="$raw" 'BEGIN { printf "output_amps %.1f\n", t/10 }'