@debugr/elastic-handler

Elastic Log Handler for Debugr

This LogHandler adds logging to Elastic via SDK.

Installation

npm install --save @debugr/elastic-handler

Usage

import { Logger, LogLevel } from '@debugr/core';
import { ElasticLogHandler } from '@debugr/elastic-handler';

const globalContext = {
  applicationName: 'example',
};

const logger = new Logger(globalContext, [
  new ElasticLogHandler({
    index: 'example-app-logs',
  }),
]);

logger.setContextProperty('jobName', 'elasticTest');

logger.info('Application started.');
// should send a new entry to the `example-app-logs` index with the following content:
// {
//   level: 30,
//   message: 'Application started.',
//   ts: '2022-09-04T12:13:14Z',
//   context: {
//     applicationName: 'example',
//     jobName: 'elasticTest',
//   },
// }

Options

The ElasticLogHandler constructor accepts a required options object as the first argument. An instance of the Client class from the @elastic/elasticsearch SDK can be passed as the second argument; if it is not provided, the constructor will attempt to create it using the provided options object. So when calling the constructor with just a single argument, the options object is a union of the log handler options defined here and the Elastic Client options. See the @elastic/elasticsearch package documentations for the available Client options. The available log handler options are as follows:

Option	Type	Default	Description
index	string, (entry: LogEntry) => string	(required)	The Elastic index to which entries will be sent. You can specify a callback to route each entry to a different index based e.g. on level.
threshold	LogLevel, number	LogLevel.TRACE	The lowest level of entries which will be logged. Any entries below this level will be ignored.
bodyMapper	(entry: LogEntry) => Record<string, any>	(see description)	A callback transforming a LogEntry into the data object to be sent to Elastic. The default mapper will leave most of the entry data as-is, except the globalContext and taskContext objects which will be merged into a single context object, and the data object which will be serialized into JSON.
errorCallback	(error: Error) => void	(see description)	A callback which will be called when sending an entry to Elastic fails. The default callback will simply log the error into the console.
errorMsThreshold	number	(none)	Minimum time since last call to errorCallback before calling it again.