# OpenTelemetry Connect Instrumentation for Node.js

[![NPM Published Version][npm-img]][npm-url]
[![Apache License][license-image]][license-image]

This module provides automatic instrumentation for the [`connect`](https://github.com/senchalabs/connect) module.

If total installation size is not constrained, it is recommended to use the [`@opentelemetry/auto-instrumentations-node`](https://www.npmjs.com/package/@opentelemetry/auto-instrumentations-node) bundle with [@opentelemetry/sdk-node](`https://www.npmjs.com/package/@opentelemetry/sdk-node`) for the most seamless instrumentation experience.

Compatible with OpenTelemetry JS API and SDK `1.0+`.

## Status

| Maturity                                           | [Component Owner](../../.github/component_owners.yml) | Compatibility         |
|----------------------------------------------------|-------------------------------------------------------|-----------------------|
| [Unmaintained](../../CONTRIBUTING.md#unmaintained) | N/A                                                   | API 1.0+<br/>SDK 1.0+ |

## Installation

This instrumentation relies on HTTP calls to also be instrumented. Make sure you install and enable both, otherwise you will have spans that are not connected to each other.

```bash
npm install --save @opentelemetry/instrumentation-http @opentelemetry/instrumentation-connect
```

### Supported Versions

- [`connect`](https://www.npmjs.com/package/connect) versions `>=3.0.0 <4`

## Usage

OpenTelemetry Connect Instrumentation allows the user to automatically collect trace data and export them to their backend of choice, to give observability to distributed systems.

To enable a specific instrumentation, pass it to `registerInstrumentations()`.
This is commonly done via `NodeSDK` for fully setting up all OpenTelemetry SDK components:

```js
const { NodeSDK } = require('@opentelemetry/sdk-node');
const { HttpInstrumentation } = require('@opentelemetry/instrumentation-http');
const { ConnectInstrumentation } = require('@opentelemetry/instrumentation-connect');

const sdk = new NodeSDK({
  instrumentations: [
    // Connect instrumentation expects HTTP layer to be instrumented
    new HttpInstrumentation(),
    new ConnectInstrumentation(),
  ],
});
sdk.start();
process.once('beforeExit', async () => { await sdk.shutdown(); });
```

## Semantic Conventions

This package implements Semantic Convention v1.33.1.

Attributes collected:

| Attribute    | Short Description                  |
|--------------|------------------------------------|
| `http.route` | The matched route (path template). |

## Useful links

- For more information on OpenTelemetry, visit: <https://opentelemetry.io/>
- For more about OpenTelemetry JavaScript: <https://github.com/open-telemetry/opentelemetry-js>
- For help or feedback on this project, join us in [GitHub Discussions][discussions-url]

## License

Apache 2.0 - See [LICENSE][license-url] for more information.

[discussions-url]: https://github.com/open-telemetry/opentelemetry-js/discussions
[license-url]: https://github.com/open-telemetry/opentelemetry-js-contrib/blob/main/LICENSE
[license-image]: https://img.shields.io/badge/license-Apache_2.0-green.svg?style=flat
[npm-url]: https://www.npmjs.com/package/@opentelemetry/instrumentation-connect
[npm-img]: https://badge.fury.io/js/%40opentelemetry%2Finstrumentation-connect.svg