fastify-aws-powertools

Introduction

Implementation of a Fastify plugin of AWS Lambda Powertools for Typescript to take advantage of Logger, Metrics, and Tracer services for AWS Lambda. Inspired by Middy middleware created by AWS Lambda Powertools team.

Getting Started

Install the dependency:

npm i fastify-aws-powertools

Add peer dependencies (if there are not installed yet):

npm i fastify @fastify/aws-lambda

Configure the plugin:

import fastifyAwsPowertool from 'fastify-aws-powertools';
import type { FastifyAwsPowertoolsOptions } from 'fastify-aws-powertools';
import type { FastifyASyncPlugin } from 'fastify';

export const plugin: FastifyASyncPlugin = async (fastify) => {
  const options: FastifyAwsPowertoolsOptions = {
    loggerOptions: {
      logEvent: true,
      clearState: true,
    },
    metricsOptions: {
      captureColdStartMetric: true,
    },
    tracerOptions: {
      captureResponse: true,
    },
  };
  fastify.register(fastifyAwsPowertool, options);
};

Also, available each plugin separately:

import { fastifyAwsPowertoolsLogger } from 'fastify-aws-powertools';
import type { FastifyAwsPowertoolsOptions } from 'fastify-aws-powertools';
import type { FastifyASyncPlugin } from 'fastify';

export const plugin: FastifyASyncPlugin = async (fastify) => {
  const options: FastifyAwsPowertoolsOptions = {
    loggerOptions: {
      logEvent: true,
      clearState: true,
    }
  };
  fastify.register(fastifyAwsPowertoolsLogger, options);
};

Dependencies

Install and configure @fastify/aws-lambda to use this plugin. See @fastify/aws-lambda.

Options

Logger, Metrics, and Tracer instances will be automatically provided if either (logger|metrics|tracer) or (logger|metrics|tracer)InstanceOptions are provided.

Logger Plugin

Property	Description	Default
logger	Logger instance, otherwise provide loggerInstanceOptions	undefined
loggerOptions	{logEvent?: boolean; resetKeys?: boolean;}	undefined
loggerInstanceOptions	See ConstructorOptions	undefined

Metrics Plugin

Property	Description	Default
metrics	Metrics instance, otherwise provide metricsInstanceOptions	undefined
metricsOptions	{throwOnEmptyMetrics?: boolean; defaultDimensions?: Record<[key: string]: string>; captureColdStartMetric?: boolean;}	undefined
metricsInstanceOptions	See MetricsOptions	undefined

Tracer Plugin

Property	Description	Default
tracer	Tracer instance, otherwise provide tracerInstanceOptions	undefined
tracerOptions	{captureResponse?: boolean;}	undefined
tracerInstanceOptions	See TracerOptions	undefined

PowerTools Plugin

Use fastifyAwsPowertoolsPlugin if you want to use all the plugins.

Example

Simple example using all the plugins:

// index.ts
import fastify from 'fastify';
import awsLambdaFastify from '@fastify/aws-lambda';
import { MetricUnits } from '@aws-lambda-powertools/metrics';
import fastifyAwsPowertool, {
  type FastifyAwsPowertoolsOptions,
} from 'fastify-aws-powertools';

const server = fastify({
  logger: false,
});

server.register(fastifyAwsPowertool);

server.get('/', async (request, reply) => {
  request.tracer.putAnnotation('successfulBooking', true);
  request.logger.info('This is a log with an extra variable', {
    foo: 'bar',
  });
  request.metrics.addMetric('successfulBooking', MetricUnits.Count, 1);
  request.metrics.addMetadata(
    'bookingId',
    '7051cd10-6283-11ec-90d6-0242ac120003',
  );
  request.metrics.publishStoredMetrics();

  return 'Hello world!';
});

const proxy = awsLambdaFastify(server);

export const handler = async (event: any, context: any) =>
  proxy(event, context);

Additional examples can be found in the examples folder.

import fastifyAwsPowertoolsPlugin, { type FastifyAwsPowertoolsOptions, Logger as FastifyLogger } from 'fastify-aws-powertools';
import { Logger } from '@aws-lambda-powertools/logger';
import { Metrics } from '@aws-lambda-powertools/metrics';
import { Tracer } from '@aws-lambda-powertools/tracer';
import { Fastify, type FastifyASyncPlugin } from 'fastify';


const serviceName = 'my-service';

const logger = new Logger({
    serviceName,
  });

const metrics = new Metrics({
  serviceName,
  namespace: serviceName,
});

const tracer = new Tracer({
  serviceName,
  captureHTTPsRequests: true,
});

tracer.provider.setLogger(logger);

export const myPlugin: FastifyASyncPlugin = async (fastify) => {

  const options: FastifyAwsPowertoolsOptions = {
    logger,
    metrics,
    tracer,
    loggerOptions: {
      logEvent: true,
      clearState: true,
    },
    metricsOptions: {
      captureColdStartMetric: true,
    },
    tracerOptions: {
      captureResponse: true,
    },
  };
  fastify.register(fastifyAwsPowertoolsPlugin, options);
};

const logger = new FastifyLogger({
  serviceName
});

const app = Fastify({ logger });