A fresh SnmpEngine() was created on every poll_device() call and never
closed. pysnmp opens a UDP transport socket per engine and doesn't release
it on GC, so each scheduler tick (default 60s, per device) leaked a file
descriptor. Over hours of polling the process hit its fd ceiling and the
listening socket could no longer accept connections — OSError: [Errno 24]
Too many open files on socket.accept(), locking up the app.
Wrap the engine in try/finally and release its transport socket via a new
_close_engine() helper that probes both pysnmp API shapes (6.2.x lextudio
camelCase, canonical 7.x snake_case); all close paths are best-effort so a
failed close never breaks the poll loop. Regression tests cover both shapes
and the never-raises contract.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
SNMP devices map onto a Steward host's detail page via _devices_for_host,
which previously matched the device's `host` field (the SNMP poll target)
against the Host's address/name — a coincidence of strings that breaks when
the poll target differs from how the Host is recorded.
Add two optional per-device config fields that decouple the binding from the
poll target:
• host_id — exact Steward Host UUID match (the explicit link)
• steward_host — friendly bind by Host name or address (case-insensitive)
An explicit binding is exclusive: a device bound to host A never implicitly
matches host B by a coincidental address. No explicit binding → existing
implicit `host`-string match (fully backward compatible).
host_panel passes host.id and badges explicitly-bound devices. plugin.yaml
documents the new fields. Tests cover explicit id/name, exclusivity, wrong
uuid, and legacy fallback.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016Jg27rgypiW2efULXJDtMC
SNMP devices are config-defined by IP/hostname, not Steward Host records, so
they had no presence on a host's page. Map them by address and embed a fragment
(mirrors the Docker per-host fragment).
- _devices_for_host(devices_cfg, address, name): case-insensitive match of a
device's configured host to the Steward host's address or name (tolerates
non-dict / host-less entries).
- Route /plugins/snmp/host/<id>: renders the matched device(s) + latest readings,
or nothing when none map (so hosts without SNMP carry no empty card).
- snmp/host_panel.html: per-device card (name · address · reachability) with a
readings grid (K/M scaling) and a History link to the full device page.
- hosts/detail.html embeds it after the Docker fragment, gated on snmp enabled.
- Unit test for the matching helper (by address, by name, no-match, blank).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016Jg27rgypiW2efULXJDtMC
The SNMP plugin ships in the image but logged "pysnmp not installed — SNMP
polling disabled" on every poll, so polling never worked. Two coupled defects:
1. The Dockerfile installed only `.[ansible]`, so the `snmp` extra (pysnmp)
was never bundled even though the plugin is first-party and shipped.
2. poller.py used the synchronous pysnmp HLAPI (`next(getCmd(...))`), which
pysnmp-lextudio 6.x removed — it's asyncio-only now — so even with the dep
present, polling would have thrown and silently returned nothing. The 5.x
line that still has the sync API isn't safe on the image's Python 3.13.
Fix:
- Dockerfile: install `.[ansible,snmp]`.
- poller.py: `poll_device_sync` → `async def poll_device` on the asyncio HLAPI,
with a dual-version import (pysnmp 7.x `pysnmp.hlapi.v3arch.asyncio`/`get_cmd`
+ async `UdpTransportTarget.create`; pysnmp-lextudio 6.2.x
`pysnmp.hlapi.asyncio`/`getCmd` + direct `UdpTransportTarget`) so a dependency
bump can't silently re-break it.
- scheduler.py: await poll_device directly; drop the run_in_executor wrapper
and the now-unused asyncio import.
- Add tests/plugins/snmp/test_poller.py covering the version→mpModel mapping,
that the poller is a coroutine, and the graceful no-pysnmp path.
Note: CI confirms import/load and the no-pysnmp path, but has no SNMP target —
live polling against real devices is verified after deploy.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016Jg27rgypiW2efULXJDtMC
bvandeusen