JBOD Monitor

REST API for monitoring drive health in JBOD enclosures on Linux.

Auto-discovers SES enclosures via sysfs, maps drives to physical slots, and exposes SMART health data.

Prerequisites

• Linux with SAS/SATA JBODs connected via HBA
• smartmontools — for smartctl (SMART data)
• sg3-utils — for sg_ses (SES enclosure data)
• Python 3.11+

# Debian/Ubuntu
apt install smartmontools sg3-utils

# RHEL/Fedora
dnf install smartmontools sg3_utils

Install

pip install -r requirements.txt

Run

The API needs root access for smartctl to query drives:

sudo uvicorn main:app --host 0.0.0.0 --port 8000

API Endpoints

Endpoint	Description
GET /api/health	Service health + tool availability
GET /api/enclosures	List all discovered SES enclosures
GET /api/enclosures/{id}/drives	List drive slots for an enclosure
GET /api/drives/{device}	SMART detail for a block device
GET /api/overview	Aggregate enclosure + drive health
GET /api/temps	Per-enclosure temperatures: named SES sensors + hotspot
GET /docs	Interactive API docs (Swagger UI)

Home Assistant (MQTT)

The monitor can publish per-enclosure temperatures to Home Assistant over MQTT using HA discovery — no HA YAML required. Each enclosure becomes a device with:

• a Hotspot sensor — the hottest reading across all SES temperature sensors and the drives housed in that enclosure (drive temps are usually the real hotspot); drive_max_c and drive_temp_count are exposed as attributes.
• one sensor per named SES temperature element (e.g. Temp Inlet, Temp Outlet), labelled from the SES element descriptor page.

Publishing is opt-in: set MQTT_HOST to enable it.

Variable	Default	Description
MQTT_HOST	(unset)	Broker host. Unset → MQTT disabled.
MQTT_PORT	1883	Broker port
MQTT_USERNAME / MQTT_PASSWORD	(unset)	Broker credentials (fallback if OpenBao unused/unavailable)
MQTT_DISCOVERY_PREFIX	homeassistant	HA discovery topic prefix
MQTT_BASE_TOPIC	jbod-monitor	State/availability topic root
MQTT_PUBLISH_INTERVAL	60	Seconds between publishes
MQTT_NODE_ID	(hostname)	Stable id for this monitor (disambiguates multiple hosts)
MQTT_CLIENT_ID	jbod-monitor-<node>	MQTT client id

Credentials via OpenBao

Broker credentials are sourced from OpenBao at startup rather than stored in plaintext (matching the homelab runtime-secret pattern). Set MQTT_SECRET_PATH to a KV v2 path holding username/password; the app reads <OPENBAO_ADDR>/v1/<OPENBAO_MOUNT>/data/<MQTT_SECRET_PATH> with the token from OPENBAO_TOKEN_FILE (or OPENBAO_TOKEN). If the read fails, it falls back to the MQTT_USERNAME/MQTT_PASSWORD env vars.

Variable	Default	Description
MQTT_SECRET_PATH	(unset)	KV v2 path holding the broker creds (e.g. home_assistant). Unset → use env creds.
MQTT_SECRET_USER_KEY	username	Key within the secret for the broker username
MQTT_SECRET_PASS_KEY	password	Key within the secret for the broker password
OPENBAO_ADDR	https://vault.adamksmith.xyz	OpenBao API base URL
OPENBAO_MOUNT	secret	KV v2 mount point
OPENBAO_TOKEN_FILE	(unset)	Path to a file containing the OpenBao token (preferred; mount read-only)
OPENBAO_TOKEN	(unset)	OpenBao token (used if no token file)

The deployed compose reads the broker user/pass from secret/home_assistant (keys mqtt_user/mqtt_pass) using the read-only claude-read token mounted at /run/secrets/openbao-token.

Topics (defaults):

homeassistant/sensor/<node>_enc<id>/hotspot/config   # retained discovery
homeassistant/sensor/<node>_enc<id>/temp<n>/config    # retained discovery
jbod-monitor/<node>/status                            # online | offline (LWT)
jbod-monitor/<node>/enclosure/<id>/state              # {"hotspot_c":42.0, "sensor_0":28.5, ...}

Availability is tracked via an MQTT LWT, so entities show unavailable in HA if the monitor stops.