Metrics

A package for creating metrics in Firehose

Installation

npm install @janiscommerce/metrics

Configuration

ENV variables

JANIS_SERVICE_NAME (required): The Role Session Name to assume role in order to put records in Firehose. METRIC_ROLE_ARN (required): The ARN to assume role in order to put records in Firehose.

API

add(clientCode, metricName, metricData)

Parameters: clientCode [String], metricName [String], metricData [Object] or [Object array] Puts the recieved metric or metrics into the janis-trace-firehose

Metric structure

The metricData [Object] parameter have the following structure:

• metricData [Object|Array]: This property is a JSON that includes all the technical data about your metric.

Metric example

{
	deliveryDate: '2022-06-03T10:00:00.000Z',
	orderId: '629e578fd32fd43cd1e41944',
	salesChannelId: '629e5797f63b83029b4df49f',
	status: 'pending'
}

on(event, callback)

Parameters: event [String], callback [Function] Calls a callback when the specified event is emitted.

Errors

The errors are informed with a MetricError. This object has a code that can be useful for a correct error handling. The codes are the following:

Code	Description
1	Invalid metric
2	Firehose Error
3	Unknown stage name

• In case of error while sending your metrics to Firehose, this package will emit an event called create-error, you can handle it using the on() method.

Usage

const Metric = require('@janiscommerce/metrics');

// Single metric send
await Metric.add('some-client', 'order-fulfillment-status', {
	warehouseName: "Example Warehouse name",
	salesChannelId: "d555345345345as67a342a",
	salesChannelName: "Example Sales Channel name"
});

// Multiple metrics send
await Metric.add('some-client', 'order-fulfillment-status', [
	{
		warehouseName: "Example Warehouse name",
		salesChannelId: "629d269fbd8f5f5da8185ba3",
		salesChannelName: "Example Sales Channel name"
	},
	{
		warehouseName: "Other Example Warehouse name",
		salesChannelId: "629d26a36c3c06aefe297df2",
		salesChannelName: "Other Example Sales Channel name"
	}
]);

// Metric creation error handling
Metric.on('create-error', (metric, err) => {
	console.error(`An error occurred while creating the metric ${err.message}`);
});

### Serverless configuration

Returns an array with the hooks needed for Metric's serverless configuration according to [Serverless Helper](https://www.npmjs.com/package/sls-helper-plugin-janis). In `path/to/root/serverless.js` add:

```js
'use strict';

const { helper } = require('sls-helper'); // eslint-disable-line
const functions = require('./serverless/functions.json');
const Metric = require('@janiscommerce/metrics');

module.exports = helper({
	hooks: [
		// other hooks
        ...functions,
        ...Metric.serverlessConfiguration
	]
});