@betit/orion-node-sdk/README.md

SDK for orion

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## Installation


```sh
$ npm install @betit/orion-node-sdk
```

## Basic example

### Note - You will need to have running all of the orion [dependencies](https://github.com/gig/orion)

Add the following into `foo.js` and then run `VERBOSE=true node foo.js`

```js
const ORION = require('@betit/orion-node-sdk');
const FOO = new ORION.Service('foo');

FOO.handle('get', (req, reply) => {
  reply(new ORION.Response('foo'));
});

FOO.listen(() => FOO.logger.createMessage('ready').send());
```

Then add the following into `bar.js` and then run `node bar.js`

```js
const ORION = require('@betit/orion-node-sdk');
const BAR = new ORION.Service('bar');

const REQ = new ORION.Request('/foo/get');
BAR.call(REQ, res => {
  // do stuff
});
```

You can find more detailed examples in the `examples` folder.

## Async example

This utility also supports functionality with Promises, so the following code can be also used:

```js
const ORION = require('@betit/orion-node-sdk');
const FOO = new ORION.Service('foo');

FOO.handle('get', async (req) => {
  return new ORION.Response('foo');
});

async function initFOO() {
  await FOO.listen();
  FOO.logger.createMessage('ready').send()
}

init().then(exit);
```

And in `bar.js`:

```js
const ORION = require('@betit/orion-node-sdk');
const BAR = new ORION.Service('bar');

const REQ = new ORION.Request('/foo/get');

async function main() {
  const res = await BAR.call(REQ);
  // do stuff
}

main().then(exit);
```

Also, subscriptions can now be looped forever using: 

```js
const ORION = require('@betit/orion-node-sdk');
const BAR = new ORION.Service('bar');

async function processEvents() {
  const producer = BAR.onAsync("event");

  while (true) {
    const event = await producer.consume();
  }
}

...
```

## Health checks

Support for health checking is present if the services are running with the environment variable `WATCHDOG=true`. Also, 
a [watchdog](https://github.com/GiG/orion-watchdog) must be running in the same environment as the service.

You can write a network health check as:

```ts
const ping = require('ping');
const host = '1.1.1.1';

async function checkNetwork(): Promise<[string, OrionError | undefined]> {
  const isAlive = await ping.promise.probe(host);
  
  if (!isAlive) {
    return [`Can't connect to ${host}`, new OrionError('CRIT')];
  } else {
    return ['', undefined];
  }
}

const healthCheck = {
  checkIsWorking: checkNetwork,
  name: 'have_I_external_net',
  timeout: 1000,
};

const SERVICE = new Service('service_name');
SERVICE.registerHealthCheck(envDependency);
```

## Tracer

The zipkin tracer is disabled by default and you can enable it using the `TRACER_ENABLED` env. variable with possible values of `1` or `true`

# Documentation

Auto-generated documentation is located [here](https://gig.github.io/orion-node-sdk/).

## Tests

  To run the test suite, first install the dependencies, then run `npm test`:

```bash
$ npm install
$ npm test
```

## License

[MIT](https://github.com/GiG/orion-node-sdk/blob/master/LICENSE)

[npm-image]: https://badge.fury.io/js/%40betit%2Forion-node-sdk.svg
[npm-url]: https://www.npmjs.com/package/@betit/orion-node-sdk
[travis-image]: https://travis-ci.org/GiG/orion-node-sdk.svg?branch=master
[travis-url]: https://travis-ci.org/GiG/orion-node-sdk
[coveralls-image]: https://coveralls.io/repos/github/GiG/orion-node-sdk/badge.svg
[coveralls-url]: https://coveralls.io/github/GiG/orion-node-sdk