Introduction

AWS Step Functions is a serverless workflow service that enables you to coordinate multiple AWS services into serverless workflows. Step Functions makes it easy to coordinate the components of distributed applications and microservices using visual workflows. With Step Functions, you can design and run workflows that stitch together services such as AWS Lambda and Amazon ECS into feature-rich applications.

In this lesson, we will learn how to use input and output with AWS Step Functions. We will cover the basics of input and output, how to use them in Step Functions, and how to use them to build a simple application.

What is Input and Output?

Input and output are two of the most fundamental concepts in computing. Input is the data that is sent to a program or system, and output is the data that is produced by the program or system. In the context of AWS Step Functions, input and output are used to pass data between different steps in a workflow.

How to Use Input and Output with AWS Step Functions

Using input and output with AWS Step Functions is relatively straightforward. In Step Functions, input and output are represented as JSON objects. Input is passed to a step as a JSON object, and output is returned from a step as a JSON object.

Passing Input to a Step

When passing input to a step, the input must be in the form of a JSON object. The JSON object must contain the key-value pairs that will be used as input for the step. For example, if you are passing input to an AWS Lambda function, the JSON object must contain the parameters that will be used by the Lambda function.

Returning Output from a Step

When returning output from a step, the output must also be in the form of a JSON object. The JSON object must contain the key-value pairs that will be used as output from the step. For example, if you are returning output from an AWS Lambda function, the JSON object must contain the results that will be returned by the Lambda function.

Building an Application with Input and Output

Now that we have a basic understanding of how to use input and output with AWS Step Functions, let’s look at how we can use them to build a simple application.

Step 1: Create an AWS Lambda Function

The first step in building our application is to create an AWS Lambda function. This Lambda function will be used to process the input and return the output.

Step 2: Create an AWS Step Function

The next step is to create an AWS Step Function. This Step Function will be used to coordinate the different steps in our application.

Step 3: Pass Input to the Step Function

The third step is to pass input to the Step Function. This input will be in the form of a JSON object, and it will contain the parameters that will be used by the Lambda function.

Step 4: Process the Input

The fourth step is to process the input. This is done by passing the input to the Lambda function, which will then process the input and return the output.

Step 5: Return the Output

The fifth step is to return the output. This is done by returning the output from the Lambda function as a JSON object.

Conclusion

In this lesson, we learned how to use input and output with AWS Step Functions. We covered the basics of input and output, how to use them in Step Functions, and how to use them to build a simple application. By using input and output with Step Functions, we can easily coordinate the components of distributed applications and microservices into feature-rich applications.