sparkDash on the LAN + a Glance widget for it

August 26, 2026 1 minute read

Deployed sparkDash (multi-DGX-Spark monitoring) to the head Spark node and wired it into Glance. Notes to self so I remember the shape.

What I did

Host: spark1 (192.168.1.205, aarch64). The container is arm64-only, so it can’t live on homelab-network (x86_64) — it runs on the head Spark itself.
Deploy: git clone + docker compose up --build. Compose uses network_mode: host, privileged: true, pid: host, and mounts /proc//sys// + nvidia-smi so it reads host metrics directly. Container name sparkDash, restart: always, listens on :5555.
Units: added via the REST API — spark1 (head) is local collectors + LLM probe on :8888 (deepseek-v4-flash-dspark), spark2 (worker) is remote over SSH with the password stored encrypted (config/sparks-secrets.json). Node config lives in config/sparks.json inside a Docker volume, not git.
DNS/reverse-proxy: appended a sparkdash.linxic.com:443 block to caddy-internal on npm-intra → 192.168.1.205:5555, then caddy reload. Cert auto-issued via Cloudflare DNS challenge. Live at https://sparkdash.linxic.com.

Bookmark in the homelab page under an “AI / Compute” group.
Live widget: a custom-api widget (glance/config/sparkdash.yml) that uses subrequests to fetch /api/sparks/spark1/metrics and /api/sparks/spark2/metrics concurrently, rendering GPU temp/util, VRAM, tok/s, KV-cache %, model, uptime per node. cache: 30s.

Gotchas that cost me time:

Go templates don’t allow .Subrequest "x".JSON — assign to a var first: `` then $s2.JSON.Int "...".
div wants exactly 2 args — wrap the whole method chain in parens (div (.JSON.Int "x") 1024), or it reads 3 args.
The /api/sparks list endpoint returns config only (no live metrics); the per-id /api/sparks/:id/metrics is the one with GPU/LLM numbers.

Glance community widget PR: glanceapp/community-widgets#311 (portable version using ${SPARKDASH_*_URL} env vars, no hardcoded IPs).
Notified the sparkDash repo: MiaAI-Lab/sparkDash#66.