Bug: "failed to read CustomSettings from the Query Request" on clean Grafana install

[Arkwraith]

Summary:
I am unable to use the Golioth WebSocket datasource plugin on a current clean install of Grafana. All queries immediately fail with a backend error about CustomSettings. This happens even on a completely fresh install with no prior data, and with a minimal configuration.

Environment:

• Grafana: 12.2.0 (also tested with latest)
• Golioth WebSocket Datasource plugin: latest (installed via GF_INSTALL_PLUGINS)
• Docker Compose setup (see below for config)
• Backend WebSocket API: working and reachable, tested with ws://topology-api:5001/ws
• No custom headers or query parameters added
• All other datasources (Prometheus, etc.) work as expected
• Error occurs even after deleting all Grafana data and starting from scratch

Error message (from docker logs grafana):
rpc error: code = Unknown desc = failed to read CustomSettings from the Query Request: error converting json.RawMessage to map[string]string

Sample log block:
level=error msg="Request Completed" method=POST path=/api/ds/query status=500 ... error="client: failed to query data: Failed to query data: rpc error: code = Unknown desc = failed to read CustomSettings from the Query Request: error converting json.RawMessage to map[string]string"

Troubleshooting Steps Taken:

• Completely removed Grafana container and data (volume wipe)
• Restarted with a named Docker volume for /var/lib/grafana
• Minimal Docker Compose config (see below)
• No custom headers, params, or settings in the datasource UI
• WebSocket endpoint confirmed working with websocat and other clients
• Tried both ws:// and wss:// (with local reverse proxy)
• Tried on various Grafana/plugin versions
• No other WebSocket datasource plugins are currently available/compatible

Docker Compose snippet
grafana:
image: grafana/grafana:12.2.0
container_name: grafana
ports:
- "3000:3000"
environment:
- GF_INSTALL_PLUGINS=golioth-websocket-datasource
volumes:
- grafana-data:/var/lib/grafana
depends_on:
- topology-api
healthcheck:
test: ["CMD", "curl", "-f", "http://localhost:3000/api/health"]
interval: 30s
timeout: 5s
retries: 3
restart: unless-stopped

volumes:
grafana-data:

Request:

• Please investigate/fix plugin backend handling of empty/missing CustomSettings
• If a workaround exists, please document it

[Shreartiq-sinara]

I have the same issue on Grafana: 12.1.0.

[5aa]

Downgrade to Grafana 11.3.0 and it works, this plugin hasn't been updated in a while and Grafana 12+ broke compatibility with it.
#46

sudo docker run -d --name=grafana \
  -p 3000:3000 \
  -v grafana-storage:/var/lib/grafana \
  -e GF_PLUGINS_PREINSTALL="golioth-websocket-datasource" \
  grafana/grafana-oss:11.3.0

[vinnitu]

still have error

failed to read CustomSettings from the Query Request: error converting json.RawMessage to map[string]string

in Grafana v11.3.0 (d9455ff7db)

[vinnitu]

services:
  grafana:
    image: grafana/grafana-oss:11.3.0
    ports:
      - "3000:3000"
    environment:
      - GF_SECURITY_ADMIN_USER=admin
      - GF_SECURITY_ADMIN_PASSWORD=admin
      - GF_PLUGINS_PREINSTALL=golioth-websocket-datasource
    volumes:
      - grafana_data:/var/lib/grafana
    restart: unless-stopped

volumes:
  grafana_data:

import { WebSocketServer } from 'ws'

const wss = new WebSocketServer({ port: 3001, host: '0.0.0.0' })
wss.on('connection', ws => {
  console.log('connection');
  ws.on('message', msg => {
    console.log(msg);
    ws.send(`echo: ${msg}`);
  })
})
console.log('ws://0.0.0.0:3001')

[vinnitu]

no 'connection' in log at all