Introducing the new AWS Step Functions Workflows Collection
Today, the AWS Serverless Developer Advocate team introduces the Step Functions Workflows Collection, a fresh experience that makes it easier to discover, deploy, and share Step Functions workflows.
Builders create Step Functions workflows to orchestrate multiple services into business-critical applications with minimal code. Customers were looking for opinionated templates that implement best practices for building serverless applications with Step Functions.
This blog post explains what Step Functions workflows are and what challenges they help solve. It shows how to use the new Step Functions workflows collection to find simple “building blocks”, reusable patterns, and example applications to help build your serverless applications with Step Functions.
Large serverless applications often comprise multiple decoupled resources. These are sometimes challenging to observe and discover errors. Step Functions is a low-code visual workflow service that helps solve this challenge. It provides instant visual understanding of an application, the services it integrates with, and any errors that might occur during execution.
Step Functions workflows comprise a sequence of steps where the output of one step passes on as input to the next. Step Functions can integrate with over 220 AWS services by using an AWS SDK integration task. This allows users to call AWS SDK actions directly without the need to write additional code.
Getting started with the Step Functions workflows collection
Explore the Step Functions workflows collection to discover new workflows. The collection has three levels of workflows:
- Fundamental: A simple, reusable building block.
- Pattern: A common reusable component of an application.
- Application: A complete serverless application or microservice.
Workflows are also categorized by multiple use-cases, including data processing, SaaS integration, and security automation. Once you find a workflow that want to use in your application:
- Choose View to go to the workflow details page.
- Choose Template from the workflow details page to view the infrastructure as code (IaC) deployment template. Here, you can see how to configure resources with AWS best practices.
The workflows collection currently supports deployable workflow templates defined with AWS Serverless Applications Model (AWS SAM) or the AWS Cloud Development Kit (AWS CDK)Structure of an AWS SAM template
AWS SAM is an open-source framework for building serverless applications. It provides shorthand syntax that makes it easier to build and deploy serverless applications. With only a few lines, you can define each resource using YAML or JSON.An AWS SAM template can have serverless-specific resources or standard AWS CloudFormation resources. When you run sam deploy, sam transforms serverless resources into CloudFormation syntax.
Structure of an AWS CDK template
The AWS CDK provides another way to define your application resources using common programming languages. The CDK is an open source framework that you can use to model your applications. As with AWS SAM, when you run ‘npx cdk deploy –app ‘ts-node .’ , the CDK transforms the template into AWS CloudFormation syntax and creates the specified resources for you.
- Choose Workflow Definition to see the Amazon States Language definition (ASL). That defines the workflow.
ASL is a JSON-based, structured language for authoring Step Functions workflows. It enables developers to filter and manipulate data at various stages of a workflow state’s execution using paths. A path is a string beginning with $ that lets you identify and filter subsets of JSON text. Learning how to apply these filters helps to build efficient workflows with minimal state transitions.The more advanced workflows in the collection show how to use intrinsic functions to manipulate payload data. Intrinsic functions are ASL constructs that help build and convert payloads without creating additional task state transitions. Use intrinsic functions in Task states within the ResultSelector field, or in a Pass state in either the Parameters or ResultSelector field. The Step Functions documentation shows examples of how to:
- Construct strings from interpolated values.
- Convert a JSON object to a string.
- Convert arguments to an array.Use the workflow definition to see how to configure each workflow state. This is helpful to understand how to define task types you are unfamiliar with and how to apply intrinsic functions to help reduce state transitions.
Use the data flow simulator to model and refine your input and output path processing.
- Follow the Download and Deployment commands to deploy the workflow into your AWS account. Use the Additional resources to read more about the workflow.
- Once you have deployed the workflow into your AWS account, continue building in the AWS Management Console with Workflow studio or locally by editing the downloaded files.
Continue building with Workflow Studio
To edit the workflow in Workflow Studio, select the workflow from the Step Functions console and choose Edit > Workflow Studio.
From here, you can drag-and-drop flow and Task states onto the canvas, then configure states and data transformations using built-in forms. Workflow Studio composes your workflow definition in real time. If you are new to Step Functions, Workflow Studio provides an easy way to continue building your first workflow that delivers business value.Continue building in your local IDE
For developers who prefer to build locally, the AWS Toolkit for VS Code enables you to define, visualize, and create your Step Functions workflows without leaving the VS Code. The toolkit also provides code snippets for seven different ASL state types and additional service integrations to speed up workflow development. To continue building locally with VS Code:
- Download the AWS Toolkit for VS Code
- Open the statemachine.asl.json definition file, and choose Render graph to visual the workflow as you build.
Contributing to the Step Functions Workflows collection
Anyone can contribute a workflow to the Step Functions workflows collection. GitHub can host new workflow files in the AWS workflows-collection repository, or in a pre-existing repository of your own.
To submit a workflow:
- Choose Submit a workflow from the navigation section.
- Fill out the GitHub issue template.
- Clone the repository, and duplicate and rename the example _workflow_model directory.
- Add the associated workflow template files, ASL, and workflow image.
- Add the required meta information to `example-workflow.json`
- Make a Pull Request to the repository with the new workflow files.
Additional guidance can be found in the repository’s PUBLISHING.md file.
Today, the AWS Serverless Developer Advocate team is launching a new Serverless Land experience called “The Step Functions workflows collection”. This helps builders search, deploy, and contribute example Step Functions workflows.
The workflows collection simplifies the Step Functions getting started experience, and also shows more advanced users how to apply best practices to their workflows. These examples consist of fundamental building blocks for workflows, common application patterns implemented as workflows, and end to end applications.
All Step Functions builders are invited to contribute to the collection. This is done by submitting a pull request to the Step Functions Workflows Collection GitHub repository. Each submission is reviewed by the Serverless Developer advocate for quality and relevancy before publishing.
You can now learn to use Step Functions with a new workshop called the AWS Step Functions Workshop. This self-paced tutorial teaches you how to use the primary features of Step Functions through a series of interactive modules.
For more information on building applications with Step Functions visit Serverlessland.com.