Adonis Prometheus 🧐

Provides a simple way to easily montior your AdonisJS application via Prometheus.

This is simply a wrapper around the NodeJS prom-client library, along with extra in-built metrics tailored for AdonisJS.

You can also build your custom metrics with this library just as you would have done with prom-client. Check out building custom metrics.

Installation

Step 1

Run this command to install:

adonis install adonis-prometheus

Step 2

Register the Adonis Prometheus provider in your AdonisJS application's start/app.js:

const providers = [
  // ...,
  "adonis-prometheus/providers/PrometheusProvider",
];

Step 3 (Optional)

There currently exists in-built metrics such as:

• HTTP Metric: Total time each HTTP request takes.
• Uptime Metric: Uptime performance of the application.
• Throughput metric: No. of request handled.

To enable them, simply register the PrometheusMiddleware as the first item in the start/kernel.js:

const globalMiddleware = [
  // Make it first in the list for reliable metric.
  "Adonis/Prometheus/Middlewares/CollectPerformanceMetric",
  "Adonis/Middleware/BodyParser",
];

Configure In-Built Metrics

There are scenarios were you want to:

• Configure the in-built metrics (e.g. change prefix, etc)
• Disable one or all the metrics entirely (and build yours from scratch).

To simply do that, simply modify the available configuration in config/prometheus.js.

Building Custom Metrics

Track total emails sent.

/** @type {typeof import('prom-client')} */
const Prometheus = use("Prometheus");

// Step 1: Create the metrics counter.
const emailMetric = new Prometheus.Counter({
  name: "send_emails",
  help: "Total Emails sent.",
  labels: ["success", "failed"],
  prefix: "",
});

const sendEmail = async () => {
  try {
    // Implement logic to send Email here.

    // Step 2: Increment success counter (if success).
    emailMetric.inc({ success: 1 });
  } catch (err) {
    // Step 2: Increment failed counter (if failed).
    emailMetric.inc({ failed: 1 });
  }
};

// Step 3: Send the Email
sendEmail().then((_) => console.log("Email Sent & Metric Captured"));

Documentation

This libary is simply a wrapper over prom-client. Hence, you can do everything prom-client does with this library.

Contributing

If you find any issue, bug or missing feature, please kindly create an issue or submit a pull request.

License

Adonis Prometheus is open-sourced software under MIT license.