chartjs-plugin-datasource-prometheus

v2.1.3

Published

4 months ago

Chart.js plugin for Prometheus datasource. Like Grafana, but standalone.

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samuelberthe

chartjs chart.js graph grafana datasource plugin prometheus client query api javascript admin series range label timeseries tsdb

Welcome to chartjs-plugin-datasource-prometheus 👋

A Prometheus datasource for ChartJS.

screenshot

Dependencies:

requires chart.js 4.0 or later.
requires a chart.js date provider to be registered, one of:
- chartjs-adapter-date-fns
- chartjs-adapter-moment
- chartjs-adapter-luxon
- if unsure, chartjs-adapter-date-fns is a good pick
requires prometheus-query 3.0 or later.

Demonstration:

https://samber.github.io/chartjs-plugin-datasource-prometheus/example/

I would be happy to add links to charts using this library. Feel free to reach me by creating an issue ;)

✨ Features

Loads time-series from Prometheus into Chart.js.
Similar to Grafana, but ported to Chart.js for public-facing web applications.
UMD compatible, you can use it with any module loader
Have been tested with line chart and (stacked) bar chart. The library should be compatible with more chart types.
Graph auto-refresh
Date interval can be absolute or relative to now
Multiple Prometheus queries into the same chart
Stacked series
Custom backend requests (useful for multitenant apps)
Hooks available (styling, labeling, data presentation...)
Custom chart messages for errors or empty Prometheus responses
Break or continuous lines when gap in data
Line styling
Send queries with your own Prometheus driver

⚠️ This project is not intented to replace Grafana. For monitoring purpose or internal company graph showing, Grafana will definitely be better and more secure.

🚀 Installation

Via npm:

npm install momentjs chart.js --save

npm install chartjs-plugin-datasource-prometheus --save

Via CDN:

Add inside of <head> the following:

<script src="https://cdn.jsdelivr.net/npm/chart.js@4/dist/chart.umd.min.js" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-adapter-date-fns@3/dist/chartjs-adapter-date-fns.bundle.min.js" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-datasource-prometheus@2/dist/chartjs-plugin-datasource-prometheus.umd.min.js" crossorigin="anonymous"></script>

💡 Note that chartjs-plugin-datasource-prometheus must be loaded after Chart.js and the date-fns adapter.

Here is used the jsDelivr CDN with specifying only a major version so any minor and patch updates will be applied automatically. If you need to use a specific version or ESM the copy link from https://www.jsdelivr.com/package/npm/chartjs-plugin-datasource-prometheus

💡 Quick start

chartjs-plugin-datasource-prometheus can be used with ES6 modules, plain JavaScript and module loaders.

<canvas id="myChart"></canvas>

Then, you need to register the plugin to enable it for all charts in the page.

Chart.registry.plugins.register(ChartDatasourcePrometheusPlugin);

Or, you can enable the plugin only for specific charts.

var chart = new Chart(ctx, {
    plugins: [ChartDatasourcePrometheusPlugin],
    options: {
        // ...
    }
});

In the example below, we display Go duration of garbage collection, for the last 12 hours:

var myChart = new Chart(ctx, {
  type: 'line',
  plugins: [ChartDatasourcePrometheusPlugin],
  options: {
    plugins: {
      'datasource-prometheus': {
        prometheus: {
          endpoint: "https://prometheus.demo.do.prometheus.io",
          baseURL: "/api/v1",   // default value
        },
        query: 'sum by (job) (go_gc_duration_seconds)',
        timeRange: {
          type: 'relative',

          // from 12 hours ago to now
          start: -12 * 60 * 60 * 1000,
          end: 0,
        },
      },
    },
  },
});

💬 Spec

Options

| Property | Required | Description | Default | | --- | :---: | --- | --- | | prometheus.endpoint | yes | Prometheus hostname | | | prometheus.baseURL | no | Prometheus metric path | "/api/v1" | | prometheus.headers | no | Headers to add to Prometheus request | | | prometheus.auth.username | no | Basic auth username | | | prometheus.auth.password | no | Basic auth password | | | prometheus.proxy.host | no | Proxy hostname | | | prometheus.proxy.port | no | Proxy port | | | prometheus.withCredentials | no | Send cookies in cross-site requests | false | | prometheus.timeout | no | Prometheus request timeout in milliseconds | 10000 | | query | yes | Prometheus query: string or function (see below). Supports multiple queries, using an array. | | | timeRange.type | no | Time range type: absolute or relative | "absolute" | | timeRange.start | yes | Time range start: Date object (absolute) or integer (relative) | | | timeRange.end | yes | Time range end: Date object (absolute) or integer (relative) | | | timeRange.step | no | Time between 2 data points | [computed] | | timeRange.minStep | no | Min time between 2 data points | null | | timeRange.msUpdateInterval | no | Update interval in millisecond | null | | fillGaps | no | Insert NaN values when values are missing in time range | false | | tension | no | Bezier curve tension of the line. Set to 0 to draw straightlines. This option is ignored if monotone cubic interpolation is used | 0.4 | | cubicInterpolationMode | no | "default" or "monotone" | "default" | | stepped | no | false, true, "before", "middle" or "after" | false | | stacked | no | Whether values are stacked or not | false | | fill | no | Fills the area under the line | false | | borderWidth | no | Should I explain this field? | 3 | | backgroundColor | no | Should I explain this field? | See library source code | | borderColor | no | Should I explain this field? | See library source code | | errorMsg.message | no | Overrides error messages | null | | errorMsg.font | no | Font of error messages | "16px normal 'Helvetica Nueue'" | | noDataMsg.message | no | Empty chart message | "No data to display" | | noDataMsg.font | no | Font of empty chart message | "16px normal 'Helvetica Nueue'" |

Hooks

Some hooks have been inserted into the library. It may help you to rewrite label names dynamically, set colors...

// 💡 For better serie labels, we are looking for a templating solution => please contribute ;)

| Property | Required | Description | Prototype | | --- | :---: | --- | --- | | findInLabelMap | no | Custom serie label | (serie: Metric) => string | | findInBorderColorMap | no | Custom serie line color | (serie: Metric) => string | | findInBackgroundColorMap | no | Custom serie background color | (serie: Metric) => string | | dataSetHook | no | Modify data on the fly, right before display | (datasets: ChartDataSet[]) => ChartDataSet[] |

Examples

Multiple queries in one chart

The query field can be an array of queries. Returned series are aggregated in a single chart.

In case you want to show those queries on different axes, you can define a custom options.scales.yAxes field.

var myChart = new Chart(ctx, {
    type: 'line',
    plugins: [ChartDatasourcePrometheusPlugin],
    options: {
        scales: {
            yAxes: [
                {position: 'left'},
                {position: 'left'},
                {position: 'right'},
            ]
        },
        plugins: {
            'datasource-prometheus': {
                prometheus: {
                    endpoint: "https://prometheus.demo.do.prometheus.io",
                },
                query: ['node_load1', 'node_load5', 'node_load15'],
                timeRange: {
                    type: 'relative',

                    // from 12 hours ago to now
                    start: -12 * 60 * 60 * 1000,
                    end: 0,
                },
            },
        },
    },
});

screenshot

Auto refresh

Animations should be disabled when chart refresh itself.

var myChart = new Chart(ctx, {
    type: 'line',
    plugins: [ChartDatasourcePrometheusPlugin],
    options: {
        animation: {
            duration: 0,
        },
        plugins: {
            'datasource-prometheus': {
                prometheus: {
                    endpoint: "https://prometheus.demo.do.prometheus.io",
                },
                query: 'node_load1',
                timeRange: {
                    type: 'relative',

                    // from 10 minutes ago to now
                    start: -1 * 10 * 60 * 1000,
                    end: 0,
                    msUpdateInterval: 5000,
                },
            },
        },
    },
});

Update

Query update:

chart.options.plugins['datasource-prometheus'].query = "new query";
chart.update({});

Start/end range update:

chart.options.plugins['datasource-prometheus'].timeRange.start = startTime;
chart.update({});

Custom queries

In the context of a multitenant application, it is not a good idea to write a query on the browser side. In that scenario, you may need to send a custom request to your backend, which is responsible for doing the final Prometheus query.

In that case, the prometheus field can be ommited. Just pass a function with the following prototype: (start: Date, end: Date, step: number) => Promise<any>.

It can be combined with traditional string queries: query: ['node_load1', customReq].

// Here, we call a fictive API that gonna query Prometheus to get the list
// of comments, wrote by the current user during the past hour.
// This endpoint will return a Prometheus-like response.
function customReq(start, end, step) {
    const startTimestamp = start.getTime() / 1000;
    const endTimestamp = end.getTime() / 1000;

    const url = `https://api.example.com/user/activity?event_type=comment.write&range_start=${startTimestamp}&end=${endTimestamp}&range_step=${step}`;
    const headers = {'Authorization': 'Bearer Ainae1Ahchiew6UhseeCh7el'};

    return fetch(url, { headers })
        .then(response => response.json())
        .then(response => response['data']);
}

const myChart = new Chart(ctx, {
    type: 'line',
    plugins: [ChartDatasourcePrometheusPlugin],
    options: {
        plugins: {
            'datasource-prometheus': {
                query: customReq,
                timeRange: {
                    type: 'relative',
                    start: -1 * 60 * 60 * 1000, // 1h ago
                    end: 0,   // now
                },
            },
        },
    },
});

🤯 Troubleshooting

CORS

Start your Prometheus instance with --web.cors.origin="www.example.com" flag or even --web.cors.origin=".*" if you like living dangerously. 😅

🔐 Security advisory

Please read the security advisory of prometheus-query library.

In the context of a multitenant application, it is not a good idea to write a query on the browser side. In that scenario, you may need to use the "custom request" feature.

🤝 Contributing

The Prometheus Datasource is open source and contributions from community (you!) are welcome.

There are many ways to contribute: writing code, documentation, reporting issues...

How-to

Author

👤 Samuel Berthe

Twitter: @samuelberthe
Github: @samber

👤 Frantisek Svoboda

Twitter: @sFrenkie
Github: @sFrenkie

💫 Show your support

Give a ⭐️ if this project helped you!

📝 License

This project is MIT licensed.