Ceph » mgr » Dashboard

In order to improve user experience and avoid the issues (deployment, configuration, maintenance) caused by dashboard-grafana-prometheus integration, it's been discussed several times the possibility of using 'native charts/widgets' for time-series.

This chartjs plugin provides an almost drop-in replacement:

var myChart = new Chart(ctx, {
  type: 'line',
  plugins: [ChartDatasourcePrometheusPlugin],
  options: {
    plugins: {
      'datasource-prometheus': {
        prometheus: {
          endpoint: "http://prom.example.com:9090",
          baseURL: "/api/v1",
        },
        query: '(ceph_pool_stored / (ceph_pool_stored + ceph_pool_max_avail)) * on(pool_id) group_left(instance,name)...',
        timeRange: {
          type: 'relative',

          // from 12 hours ago to now
          start: -12 * 60 * 60 * 1000,
          end: end,

          // refresh every 5s
          msUpdateInterval: 5 * 1000,
        },
      },
    },
  },
});

This library relies on the client side directly polling Prometheus, and that has a few issues (CORS, http/https, networking). An alternative approach, similar to what it's already done with RGW/iSCSI/..., could be to create a controller in Dashboard back-end acting as a reverse proxy for the prometheus API (this could, btw, provide HA for free).