npm package: @opencensus/exporter-prometheus
Description: OpenCensus Exporter Prometheus allows user to send collected stats to Prometheus
Author: Google Inc.
Latest version: 0.1.0

# OpenCensus Prometheus Stats Exporter
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The OpenCensus Prometheus Stats Exporter allows the user to send collected stats with [OpenCensus Core](https://github.com/census-instrumentation/opencensus-core) to Prometheus.

[Prometheus](https://prometheus.io/) is a monitoring system that collects metrics, by scraping exposed endpoints at regular intervals, evaluating rule expressions. It can also trigger alerts if certain conditions are met. For assistance setting up Prometheus, [Click here](https://opencensus.io/codelabs/prometheus/#0) for a guided codelab.

This package is still at an early stage of development, and is subject to change.

## Installation

Install OpenCensus Prometheus Exporter with:
```bash
npm install @opencensus/core
npm install @opencensus/exporter-prometheus
```

## Usage

Create & register the exporter on your application.

For Javascript:
```javascript
const { globalStats } = require('@opencensus/core');
const { PrometheusStatsExporter } = require('@opencensus/exporter-prometheus');

// Add your port and startServer to the Prometheus options
const exporter = new PrometheusStatsExporter({
  port: 9464,
  startServer: true
});
```

Now, register the exporter.

```javascript
// Pass the created exporter to Stats
globalStats.registerExporter(exporter);
```

Similarly for TypeScript (Since the source is written in TypeScript):
```typescript
import { PrometheusStatsExporter } from '@opencensus/exporter-prometheus';
import { globalStats } from '@opencensus/core';

// Add your port and startServer to the Prometheus options
const options = {port: 9464, startServer: true};
const exporter = new PrometheusStatsExporter(options);

// Pass the created exporter to Stats
globalStats.registerExporter(exporter);
```

Viewing your metrics:

With the above you should now be able to navigate to the Prometheus UI at: <http://localhost:9464/metrics>

## Useful links
- To learn more about Prometheus, visit: <https://prometheus.io/>
- For more information on OpenCensus, visit: <https://opencensus.io/>
- To checkout OpenCensus for Node.js, visit: <https://github.com/census-instrumentation/opencensus-node>
- For help or feedback on this project, join us on [gitter](https://gitter.im/census-instrumentation/Lobby)

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[dependencies-status]: https://david-dm.org/census-instrumentation/opencensus-node/status.svg?path=packages/opencensus-exporter-prometheus
[devdependencies-status]:
https://david-dm.org/census-instrumentation/opencensus-node/dev-status.svg?path=packages/opencensus-exporter-prometheus

## LICENSE

Apache License 2.0