add grafan DataSource for Prometheus

[blro-ep]

Could be solved via Grafan API with cloud-init. cloud-init-podman.yaml) sudo curl -X "POST" "http://localhost:3000/api/datasources" -H "Content-Type:application/json" --user admin:admin --data-binary @prometheus.json

{ "id": 1, "uid": "dcf7f9bf-4909-4403-8401-f4d4f9265d63", "orgId": 1, "name": "Prometheus", "type": "prometheus", "typeName": "Prometheus", "typeLogoUrl": "public/app/plugins/datasource/prometheus/img/prometheus_logo.svg", "access": "proxy", "url": "http://xxx.xxx.xxx.xxx:9090", "user": "", "database": "", "basicAuth": false, "isDefault": true, "jsonData": { "httpMethod": "POST" }, "readOnly": false }