@mattwyskiel/bootstrap-microservice v0.3.0

Microservice Bootstrapper

A few simple utils that are generally used by all my AWS-based Microservices.

Installation

NPM

npm install --save-dev @mattwyskiel/bootstrap-microservice

Yarn

yarn add --dev @mattwyskiel/bootstrap-microservice

Usage

npx bootstrap-microservice [options] [command] / yarn bootstrap-microservice [options] [command]

CLI to add opinionated common boilerplate to SST-generated TypeScript microservices

Options:
  -V, --version          output the version number
  -h, --help             display help for command

Commands:
  boilerplate [options]
  codeformat [options]
  help [command]         display help for command

Commands

boilerplate

bootstrap-microservice boilerplate [options]

Options:
  -d, --dir <directory>     directory to output folder "lib/" of boilerplate code files in (relative to current working
                            directory) (default: "./")
  -p --project <directory>  root project directory which contains package.json file (default: "./")
  -h, --help                display help for command

This tool adds the following functionality to the libs/ directory

Logger

This library exposes a pre-configured winston logger with the following settings:

1. When deployed, outputs logs as JSON, including the timestamp, with a default minimum log level of info (can be set using the LOG_LEVEL environment variable)
2. When running locally (process.env.IS_LOCAL), outputs to the console with the following custom format:

${level.toUpperCase()} - ${message}
${detailIfExists}

For example:

INFO - Incoming Request
{
  "body": {
    "foo": "bar"
  },
  "headers: {
    "x-foo": "bar"
  }
}

And the formatter has logic such that if there is only one field in the details object, then it will just print that.

For example, if the above request details only had the body, the log could come across like the following:

INFO - Request Body
{
  "foo": "bar"
}

Usage

import { logger } from '@mattwyskiel/microservice-boilerplate';

logger.info('This is a log!');

Request Monitoring

This library implements a middy middleware that does the following:

1. Adds the AWS Request ID to the logs for grouping and searchability.
2. If the code is deployed, logs the API Gateway proxy requests and responses.
3. Intercepts all errors and normalizes them for consistent

Usage

import { requestMonitoring } from '@mattwyskiel/microservice-boilerplate';
import middy from '@middy/core';

// define handler

export default middy(handler).use(requestMonitoring());

Amazon API Gateway Helper Types

This library defines some helper types that enable a strongly-typed API Gateway request body.

import { APIGatewayProxyEventV2, APIGatewayProxyResultV2, Handler } from 'aws-lambda';
import { FromSchema } from 'json-schema-to-ts';

export type APIGatewayJSONBodyEvent<S> = Omit<APIGatewayProxyEventV2, 'body'> & {
  body: FromSchema<S>;
};

export type APIGatewayJSONBodyEventHandler<S> = Handler<
  APIGatewayJSONBodyEvent<S>,
  APIGatewayProxyResultV2
>;

The library also exposes a helper function that can send a 'success' JSON response:

import { json } from '@mattwyskiel/microservice-boilerplate';
import { APIGatewayProxyHandlerV2 } from 'aws-lambda';

export const handler: APIGatewayProxyHandlerV2 = event => {
  return json({
    message: `Hello, World! Your request was received at ${event.requestContext.time}.`,
  });
};

codeformat

Usage: bootstrap-microservice codeformat [options]

Options:
  -p --project <directory>  root project directory which contains package.json file (default: "./")
  -h, --help                display help for command

This tool installs eslint and prettier and provides default configs for both, for use in TypeScript projects.