npm package: @openaddresses/cfn-config
Description: Quickly configure and start AWS CloudFormation stacks
Author: Mapbox
Latest version: 8.0.1

Quickly configure and start AWS CloudFormation stacks.

![cfn-config](https://cloud.githubusercontent.com/assets/515424/17630129/c42d7e52-6072-11e6-8029-0a7aa3952193.gif)

## Features

- CLI tool provides prompting for easy stack configuration and verification of intended changes to your stack.
- Save parameter values in a specified S3 bucket for easy reuse and sharing privately.
- Deploy templates written as either JSON or JavaScript files. JavaScript files must either export JSON directly, or export a function that asynchronously provides JSON.
- JavaScript library functions provide access to high-level routines (e.g. create, update, delete) as well as low-level utilities you can use to build your own deployment workflows.
- Optional KMS encryption of sensitive parameter values.

## Prerequisites

To use cfn-config, you will need to have two (or more) S3 buckets ready:

- config bucket: this is a bucket where cfn-config will save stack configurations (parameter values) that can be reused.

- template buckets: cfn-config will upload your template file to a bucket each time you perform a `create` or `update` action. There must be a bucket in any region to which you intend to deploy CloudFormation stacks. The suggested default bucket names are:

  ```
  cfn-config-templates-{account id}-{region}
  ```

  If you create buckets matching this pattern in each region you wish to use, then you do not need to specify the `--template-bucket` option when using cfn-config's CLI tool.

## CLI Installation

cfn-config includes a CLI tool for working with CloudFormation stacks. Install globally with `npm` to use the CLI commands:

```
$ npm install -g @mapbox/cfn-config
```

## JavaScript Installation

Include cfn-config into your project to incorporate/extend its functionality. Add to your project's package.json by running the following from your project's directory:

```
$ npm install --save @openaddresses/cfn-config
```

Then, in your scripts:

```js
import CFNConfig, { Commands } from '@openaddresses/cfn-config';
```

## JavaScript Usage

High-level prompting routines to create, update, and delete stacks are provided, as well as to fetch detailed information about a stack or to save an existing stack's configuration to S3.

First, create a client and commands object:

```js
import CFNConfig, { Commands } from '@openaddresses/cfn-config';

const client = {
    region: 'us-east-1',
    credentials: {
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY
    }
};

const options = {
    name: 'my-stack', // the base name of the stack
    region: 'us-east-1', // the region where the stack resides
    templatePath: '~/my-stack/cfn.template.json', // the template file
    configBucket: 'my-cfn-configurations', // bucket for configuration files
    templateBucket: 'cfn-config-templates-123456789012-us-east-1' // bucket for templates
    tags: [{ // Tags applied to all sub-resources within a stack
        Key: 'developer',
        Value: 'ingalls'
    }]
};

const commands = new Commands(client, options);
const cfn = new CFNConfig(client, options);
```

Then, perform the desired operation:

```js
// Create a stack called `my-stack-testing`
try {
    await commands.create('testing', '~/my-stack/cfn.template.json');
    console.log('Create succeeded');
} catch (err) {
    console.error(`Create failed: ${err.message}`);
}

// Update the stack with a different version of the template
try {
    await commands.update('testing', '~/my-stack/cfn.template-v2.json');
    console.log('Update succeeded');
} catch (err) {
    console.error(`Update failed: ${err.message}`);
}

// Save the stack's configuration to S3
try {
    await commands.save('testing');
    console.log('Saved configuration');
} catch (err) {
    console.error(`Failed to save configuration: ${err.message}`);
}

// Get information about the stack
try {
    await commands.info('testing');
    console.log(JSON.stringify(info, null, 2));
} catch (err) {
    console.error(`Failed to read stack info: ${err.message}`);
}

// Delete the stack
try {
    await commands.delete('testing');
    console.log('Delete succeeded');
} catch (err) {
    console.error(`Delete failed: ${err.message}`);
}
```

For low-level functions, see documentation in the code for now. More legible docs are to come.