log4js-appender-cloudwatch

log4js appender - AWS CloudWatch

This module provides a custom appender for log4js that sends logs to AWS CloudWatch using the AWS v3 SDK.

Installation

npm registry

npm install log4js-appender-cloudwatch

Configuration

Roles

Required

logs:PutLogEvents

To enable the appender to create a group and log stream in AWS, adition roleare required.

logs:PutLogEvents
logs:CreateLogGroup
logs:CreateLogStream
logs:DescribeLogStreams
logs:DescribeLogGroups

Reqired for testing.

To run tests, create .env with AWS access and secret keys.

logs:PutLogEvents
logs:GetLogEvents

{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Action": [
				"logs:PutLogEvents",
				"logs:GetLogEvents"
			],
			"Effect": "Allow",
			"Resource": "*"
		}
	]
}

TypeScript

If you're using TypeScript, importing this library as a side effect will automatically merge the log4js interface Appenders. This merging enables autocomplete for the appenders configuration, providing convenient access to its properties.

import "log4js-appender-cloudwatch";

Example

import log4js from "log4js";

import "log4js-appender-cloudwatch";

log4js.configure({
	appenders: {
		cloudwatch: {
			type: "log4js-appender-cloudwatch",
			accessKeyId: "<secret>",
			secretAccessKey: "<secret>",
			region: "<config>",
			logGroupName: "<config>",
			logStreamName: "<config>",
			batchSize: 10,
			bufferTimeout: 1000, // in ms
		},
	},
	categories: {
		default: {
			level: "debug",
			appenders: [
				"cloudwatch",
			],
		},
	},
});

const log = log4js.getLogger();
// ...

Options

type

Required
Type: log4js-appender-cloudwatch

Type of appender that's loaded from node_modules.

batchSize

Required
Type: number

Maximum number of log events to include in a single batch when sending. Once the batch size is reached, it will be sent to CloudWatch.

bufferTimeout

Required
Type: number

Maximum time (in milliseconds) to wait before sending a batch of logs, regardless of the batch size. If the timeout is reached before the batch size is met, the logs will be sent.

logGroupName (aws)

Required
Type: string

The name of the log group in AWS CloudWatch Logs where your logs are stored.

logStreamName (aws)

Required
Type: string

The name of the log stream within the specified log group where your logs are stored.

region (aws)

Required
Type: string

The AWS region where your log group and log stream are located.

accessKeyId (aws)

Required
Type: string

Your AWS access key ID for authentication.

secretAccessKey (aws)

Required
Type: string

Your AWS secret access key for authentication.

Testing

To test this library during development, you'll need to provide your AWS credentials. These credentials should be stored securely in a .env file located at the root of your project directory.

# .env
accessKeyId="<key>"
secretAccessKey="<key>"

Then, you're ready to run tests:

npm test