s2-aws-simple

aws-simple

A Node.js interface for AWS that allows easy configuration and deployment of simple web apps.

Introduction

aws-simple allows you to easily create and deploy an API Gateway with a custom domain and optional alias record, host static web resources via S3, and provision public backend APIs via Lambda. In addition, a local DEV server can be started to emulate the resulting AWS infrastructure.

Getting Started

Install dependencies

npm install aws-simple aws-cdk@next --save-dev

Create a config file

To use the aws-simple CLI you have to create a top-level config file named aws-simple.config.js which exports an object compatible to the App interface.

For example, a config file with the following content describes a simple app consisting of a single static HTML file:

exports.default = {
  appName: 'my-app',
  routes: (port) => ({
    '/': {kind: 'file', filename: 'dist/index.html'},
  }),
};

Note: The routes function optionally gets a port argument. It is set when the function is called in the context of the aws-simple start [options] CLI command. This gives the opportunity to create different routes for either AWS or the local DEV environment.

Link: As a real-world example, you can find the aws-simple configuration for one of my open source applications here.

Create an AWS IAM user

You need to create an AWS IAM user with programmatic access and the following attached policy:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "apigateway:*",
        "cloudformation:*",
        "iam:*",
        "lambda:*",
        "route53:*",
        "s3:*"
      ],
      "Resource": "*"
    }
  ]
}

Optional: Create an AWS profile

You can install the aws CLI, e.g. with:

brew install awscli

You can then set up the AWS profile using the credentials from the AWS IAM user you just created:

aws configure

AWS Access Key ID [None]: ********************
AWS Secret Access Key [None]: ****************************************
Default region name [None]: eu-central-1
Default output format [None]: json

If a profile other than the default profile is to be set up, the aws CLI can be called with the --profile CLI option, e.g.:

aws configure --profile my-profile

As an alternative to using the aws CLI, you can create the following files manually:

cat ~/.aws/credentials

[default]
aws_access_key_id = ********************
aws_secret_access_key = ****************************************

cat ~/.aws/config

[default]
output = json
region = eu-central-1

Set the AWS profile

The following two environment variables AWS_PROFILE and AWS_DEFAULT_PROFILE are evaluated in the specified order. If neither of the two environment variables is set, the default profile is used.

The following is an example of setting a specific profile:

AWS_PROFILE=my-profile npx aws-simple list

Set the AWS credentials

The following two environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY are evaluated. If these are not set, an attempt is made to read the credentials from the AWS shared credentials file using the AWS profile. The default location of the file (~/.aws/credentials) can be overwritten by setting the environment variable AWS_SHARED_CREDENTIALS_FILE.

Set the AWS region

The following two environment variables AWS_REGION and AWS_DEFAULT_REGION are evaluated in the specified order. If neither of the two environment variables is set, an attempt is made to read the region from the AWS config file using the AWS profile. The default location of the file (~/.aws/config) can be overwritten by setting the environment variable AWS_CONFIG_FILE.

Bootstrap the AWS environment

Before you can use the AWS CDK you must bootstrap your AWS environment to create the infrastructure that the AWS CDK CLI needs to deploy your app:

npx cdk bootstrap --app 'npx aws-simple create'

Start a local DEV server

npx aws-simple start

Note: When changing the aws-simple config file, the DEV server must be restarted. If a bundler such as Parcel or Webpack is used, its watcher must be started in addition to the DEV server.

Deploy a stack to AWS

Create and deploy a stack using the CDK:

npx cdk deploy --app 'npx aws-simple create'

The name of the deployed stack consists of the app name (e.g. my-app) in combination with the app version (e.g. latest) such as aws-simple--my-app--latest.

Caution: Re-deploying an already deployed stack (so a stack with the same name) will remove all tags set with aws-simple tag [options].

Upload files to S3:

npx aws-simple upload

Example package.json scripts:

{
  "scripts": {
    "deploy": "cdk deploy --app 'npx aws-simple create'",
    "postdeploy": "aws-simple upload"
  }
}

Note: In a CI pipeline the deploy script should be called with the additional argument --require-approval never, e.g. npm run deploy -- --require-approval never.

Configuration

Use TypeScript for auto-completion support

TypeScript 2.3 and later support type-checking in *.js files by adding a // @ts-check comment to them:

// @ts-check

/**
 * @type {import('aws-simple').App}
 */
exports.default = {
  appName: 'my-app',
  routes: () => ({
    /* ... */
  }),
};

Configure a custom domain

In order to use a custom domain, a public certificate and a public hosted zone must be created manually. You can then configure a custom domain as follows:

const appVersion = process.env.APP_VERSION;

exports.default = {
  appName: 'my-app',
  appVersion,
  customDomain: {
    certificateArn:
      'arn:aws:acm:eu-central-1:************:certificate/********-****-****-****-************',
    hostedZoneId: '**************',
    hostedZoneName: 'example.com',
    aliasRecordName: appVersion ? appVersion : undefined,
  },
  routes: () => ({
    /* ... */
  }),
};

Note: Different app versions allow multiple stacks of the same app to be deployed simultaneously. In this case the optional aliasRecordName property is used to give each stack its own URL, e.g. example.com or beta.example.com (APP_VERSION=beta).

Configure a Lambda function

You can configure a Lambda function that can be accessed via GET request under the /hello path as follows:

exports.default = {
  appName: 'my-app',
  routes: () => ({
    '/hello': {kind: 'function', filename: 'dist/hello.js'},
  }),
};

The contents of file dist/hello.js could look like this:

async function handler() {
  return {
    statusCode: 200,
    headers: {'Content-Type': 'application/json'},
    body: JSON.stringify('Hello, World!'),
  };
}

exports.handler = handler;

Note: If external modules are to be referenced in the Lambda function, it must be bundled with a bundler such as Webpack (in this case you have to set the target to node: {target: 'node'}) to create a single self-contained file.

Configure an S3 file

You can configure an S3 file that can be accessed via GET request under the / path as follows:

exports.default = {
  appName: 'my-app',
  routes: () => ({
    '/': {kind: 'file', filename: 'dist/index.html'},
  }),
};

Configure an S3 folder

You can configure an S3 folder that can be accessed via GET request under the /assets/* path as follows:

exports.default = {
  appName: 'my-app',
  routes: () => ({
    '/assets': {kind: 'folder', dirname: 'dist/assets'},
  }),
};

Note: All files contained in the folder specified under the dirname property are loaded into the S3 bucket associated with the stack using the aws-simple upload [options] command.

Important: Nested folders are ignored! Thus a separate route must be created for each nested folder.

Enable binary support

You can specify media types (e.g. image/png, application/octet-stream, etc.) to be treated as binary as follows:

exports.default = {
  appName: 'my-app',
  routes: () => ({
    '/images': {
      kind: 'folder',
      dirname: 'dist/images',
      binaryMediaTypes: ['image/gif', 'image/jpeg', 'image/png'],
    },
  }),
};

Important: Folders may only contain either binary or non-binary files.

Enable CORS

To enable CORS for a route, you can set its enableCors property to true:

exports.default = {
  appName: 'my-app',
  routes: () => ({
    '/': {kind: 'file', filename: 'dist/index.html', enableCors: true},
    '/assets': {kind: 'folder', dirname: 'dist/assets', enableCors: true},
    '/hello': {kind: 'function', filename: 'dist/hello.js', enableCors: true},
  }),
};

Additionally, Lambda functions must explicitly set any required CORS headers like Access-Control-Allow-Origin on their response:

async function handler() {
  return {
    statusCode: 200,
    headers: {
      'Content-Type': 'application/json',
      'Access-Control-Allow-Origin': '*',
    },
    body: JSON.stringify('Hello, World!'),
  };
}

exports.handler = handler;

Caution: During a transition period, the old configuration format continues to be used under the hood. This means that CORS cannot be activated by route. As soon as a route has activated CORS, this applies to all routes!

Enable basic authentication

To enable basic authentication for a route, you can set its enableAuthentication property to true:

exports.default = {
  appName: 'my-app',
  authentication: {
    username: process.env.USERNAME,
    password: process.env.PASSWORD,
  },
  routes: () => ({
    '/': {
      kind: 'file',
      filename: 'dist/index.html',
      enableAuthentication: true,
    },
    '/assets': {
      kind: 'folder',
      dirname: 'dist/assets',
      enableAuthentication: true,
    },
    '/hello': {
      kind: 'function',
      filename: 'dist/hello.js',
      enableAuthentication: true,
    },
  }),
};

Note: Basic authentication is not simulated by the local DEV server.

Configure a single-page application (SPA)

It can be useful to deliver the same single-page application under different paths. Instead of specifying multiple routes, you can set the catchAll property of a file or function route to true:

exports.default = {
  appName: 'my-app',
  routes: (port) => ({
    '/': {kind: 'file', filename: 'dist/index.html', catchAll: true},
    '/assets': {kind: 'folder', dirname: 'dist/assets'},
    '/hello': {kind: 'function', filename: 'dist/hello.js'},
  }),
};

Troubleshooting

Some changes to an existing stack require a redeployment of the API Gateway. So if changes to a stack do not work, the aws-simple redeploy command might help.

CLI Usage

Usage: aws-simple <command> [options]

Commands:
  aws-simple create [options]       Create a stack using the CDK
  aws-simple upload [options]       Upload files to S3
  aws-simple start [options]        Start a local DEV server
  aws-simple list [options]         List all deployed stacks
  aws-simple tag [options]          Tag a deployed stack
  aws-simple clean-up [options]     Clean up old deployed stacks
  aws-simple redeploy [options]     Redeploy the API Gateway
  aws-simple flush-cache [options]  Flush the cache of the API Gateway

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]

A Node.js interface for AWS that allows easy configuration and deployment of
simple web apps.

Create a stack using the CDK

aws-simple create [options]

Create a stack using the CDK

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]

Examples:
  npx aws-simple create
  npx cdk deploy --app 'npx aws-simple create'

Upload files to S3

aws-simple upload [options]

Upload files to S3

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]

Examples:
  npx aws-simple upload

Start a local DEV server

aws-simple start [options]

Start a local DEV server

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]
      --port     The port to listen on if available, otherwise listen on a
                 random port                            [number] [default: 3000]
      --cache    Enable caching of successful caching-enabled Lambda function
                 results per request URL              [boolean] [default: false]
      --verbose  Enable logging of successful Lambda function results
                                                      [boolean] [default: false]

Examples:
  npx aws-simple start
  npx aws-simple start --port 3001 --cache --verbose

List all deployed stacks

aws-simple list [options]

List all deployed stacks

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]

Examples:
  npx aws-simple list

Tag a deployed stack

aws-simple tag [options]

Tag a deployed stack

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]
      --add      The tags to add                           [array] [default: []]
      --remove   The tags to remove                        [array] [default: []]
      --yes      The confirmation message will automatically be answered with
                 yes                                  [boolean] [default: false]

Examples:
  npx aws-simple tag --add latest release --remove prerelease
  npx aws-simple tag --add prerelease --yes

Clean up old deployed stacks

aws-simple clean-up [options]

Clean up old deployed stacks

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]
      --min-age  The minimum age (in days) of a stack for deletion
                                                          [number] [default: 30]
      --exclude  Tags that exclude a stack from deletion   [array] [default: []]
      --yes      The confirmation message will automatically be answered with
                 yes                                  [boolean] [default: false]

Examples:
  npx aws-simple clean-up
  npx aws-simple clean-up --min-age 14 --exclude release prerelease --yes

Redeploy the API Gateway

aws-simple redeploy [options]

Redeploy the API Gateway

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]

Examples:
  npx aws-simple redeploy

Flush the cache of the API Gateway

aws-simple flush-cache [options]

Flush the cache of the API Gateway

Options:
      --version  Show version number                                   [boolean]
  -h, --help     Show help                                             [boolean]

Examples:
  npx aws-simple flush-cache

Development

If you want to develop locally on this project, please make sure you have installed the latest 16.x version of Node.js and the latest 7.x version of npm. Please run the following commands in the order given to get started:

npm install
npm run setup
npm run ci

Note: This project uses onecmd. The configuration files are created using onecmd with the npm run setup command and hidden in VS Code.

---

Copyright 2019-2021 Clemens Akens. All rights reserved. MIT license.