For a demo

<code>
docker run -d -p 3000:3000 \
--name grafana \
-v grafana-storage:/var/lib/grafana \
-v grafana-config:/etc/grafana \
grafana/grafana


cat > dummy.json
{"cpu": 5}
Ctrl-D

python3 -m http.server
</code>

Default credentials are: admin/admin

Install the "Infinity" plugin (don't set the Base URL; we don't need it)

Go to the Dashboard, and use the URL "http://host.docker.internal:8000/dummy.json", specify the field "cpu" and a "Number" type.