README.md

@aws-sdk/client-cloudformation

Description

AWS SDK for JavaScript CloudFormation Client for Node.js, Browser and React Native.

AWS CloudFormation

AWS CloudFormation allows you to create and manage AWS infrastructure deployments predictably and repeatedly. You can use AWS CloudFormation to leverage AWS products, such as Amazon Elastic Compute Cloud, Amazon Elastic Block Store, Amazon Simple Notification Service, Elastic Load Balancing, and Auto Scaling to build highly-reliable, highly scalable, cost-effective applications without creating or configuring the underlying AWS infrastructure.

With AWS CloudFormation, you declare all of your resources and dependencies in a template file. The template defines a collection of resources as a single unit called a stack. AWS CloudFormation creates and deletes all member resources of the stack together and manages all dependencies between the resources for you.

For more information about AWS CloudFormation, see the AWS CloudFormation Product Page.

Amazon CloudFormation makes use of other AWS products. If you need additional technical information about a specific AWS product, you can find the product's technical documentation at docs.aws.amazon.com.

Installing

To install the this package, simply type add or install @aws-sdk/client-cloudformation using your favorite package manager:

• npm install @aws-sdk/client-cloudformation
• yarn add @aws-sdk/client-cloudformation
• pnpm add @aws-sdk/client-cloudformation

Getting Started

Import

The AWS SDK is modulized by clients and commands. To send a request, you only need to import the CloudFormationClient and the commands you need, for example CancelUpdateStackCommand:

// ES5 example
const { CloudFormationClient, CancelUpdateStackCommand } = require("@aws-sdk/client-cloudformation");

// ES6+ example
import { CloudFormationClient, CancelUpdateStackCommand } from "@aws-sdk/client-cloudformation";

Usage

To send a request, you:

• Initiate client with configuration (e.g. credentials, region).
• Initiate command with input parameters.
• Call send operation on client with command object as input.
• If you are using a custom http handler, you may call destroy() to close open connections.

// a client can be shared by different commands.
const client = new CloudFormationClient({ region: "REGION" });

const params = {
  /** input parameters */
};
const command = new CancelUpdateStackCommand(params);

Async/await

We recommend using await operator to wait for the promise returned by send operation as follows:

// async/await.
try {
  const data = await client.send(command);
  // process data.
} catch (error) {
  // error handling.
} finally {
  // finally.
}

Async-await is clean, concise, intuitive, easy to debug and has better error handling as compared to using Promise chains or callbacks.

Promises

You can also use Promise chaining to execute send operation.

client.send(command).then(
  (data) => {
    // process data.
  },
  (error) => {
    // error handling.
  }
);

Promises can also be called using .catch() and .finally() as follows:

client
  .send(command)
  .then((data) => {
    // process data.
  })
  .catch((error) => {
    // error handling.
  })
  .finally(() => {
    // finally.
  });

Callbacks

We do not recommend using callbacks because of callback hell, but they are supported by the send operation.

// callbacks.
client.send(command, (err, data) => {
  // proccess err and data.
});

v2 compatible style

The client can also send requests using v2 compatible style. However, it results in a bigger bundle size and may be dropped in next major version. More details in the blog post on modular packages in AWS SDK for JavaScript

import * as AWS from "@aws-sdk/client-cloudformation";
const client = new AWS.CloudFormation({ region: "REGION" });

// async/await.
try {
  const data = await client.cancelUpdateStack(params);
  // process data.
} catch (error) {
  // error handling.
}

// Promises.
client
  .cancelUpdateStack(params)
  .then((data) => {
    // process data.
  })
  .catch((error) => {
    // error handling.
  });

// callbacks.
client.cancelUpdateStack(params, (err, data) => {
  // proccess err and data.
});

Troubleshooting

When the service returns an exception, the error will include the exception information, as well as response metadata (e.g. request id).

try {
  const data = await client.send(command);
  // process data.
} catch (error) {
  const { requestId, cfId, extendedRequestId } = error.$metadata;
  console.log({ requestId, cfId, extendedRequestId });
  /**
   * The keys within exceptions are also parsed.
   * You can access them by specifying exception names:
   * if (error.name === 'SomeServiceException') {
   *     const value = error.specialKeyInException;
   * }
   */
}

Getting Help

Please use these community resources for getting help. We use the GitHub issues for tracking bugs and feature requests, but have limited bandwidth to address them.

• Visit Developer Guide or API Reference.
• Check out the blog posts tagged with aws-sdk-js on AWS Developer Blog.
• Ask a question on StackOverflow and tag it with aws-sdk-js.
• Join the AWS JavaScript community on gitter.
• If it turns out that you may have found a bug, please open an issue.

To test your universal JavaScript code in Node.js, browser and react-native environments, visit our code samples repo.

Contributing

This client code is generated automatically. Any modifications will be overwritten the next time the @aws-sdk/client-cloudformation package is updated. To contribute to client you can check our generate clients scripts.

License

This SDK is distributed under the Apache License, Version 2.0, see LICENSE for more information.