prometheus-metrics

Utility to generate prometheus metrics based on tasks from config

How to use

Install

npm install @akasybe/prometheus-metrics --save-dev

Create config file

Create file metrics.config.js in root directory:

module.exports = {
  output: "build/metrics.txt",
  tasks: [
    {
      type: "size",
      path: "build/*.js",
      labels: {
        compression: "gzip",
        type: "javascript",
        project: "app",
      },
      // optional, 'bundle_size_bytes_total` is default value
      // metricName: "bundle_size_bytes_total"
    },
    {
      type: "custom",
      // client is default export from 'prom-client' library
      resolve: function(client) {
        // you can create any valid metric, please refer to 'prom-client' docs
        const metric = new client.Counter({
          name: "metric_name",
          help: "metric_help",
        });

        // calculate metric value
        metric.inc(1);

        // and do not forget to return metric
        return metric;
      },
    },
  ],
};

Supported 2 task types: size and custom.

• Task with type size should have path as glob pattern and labels (these are prometheus labels)
• Task with type custom should have resolve method that returns single prom-client metric

Add script

Add script in package.json:

"scripts": {
  "metrics": "prometheus-metrics"
}

Run

npm run metrics

Now go to output directory and look at metrics.txt file