# AWS Step Functions to execute AWS Lambda Through a Cloudwatch event rule

The Terraform template deploys a AWS Step Function, a AWS Lambda function, a Cloudwatch Event Rule and the minimum IAM resources required to run the application.

This pattern demonstrates the use of Terraform modules and configures a Cloudwatch Event rule to start execution of a AWS Step Function which in turn invokes a AWS Lambda

Learn more about this pattern at Serverless Land Patterns: https://serverlessland.com/patterns/eventbridge-sfn-lambda-terraform.

Important: this application uses various AWS services and there are costs associated with these services after the Free Tier usage - please see the [AWS Pricing page](https://aws.amazon.com/pricing/) for details. You are responsible for any AWS costs incurred. No warranty is implied in this example.

## Requirements

* [Create an AWS account](https://portal.aws.amazon.com/gp/aws/developer/registration/index.html) if you do not already have one and log in. The IAM user that you use must have sufficient permissions to make necessary AWS service calls and manage AWS resources.
* [AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/install-cliv2.html) installed and configured
* [Git Installed](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git)
* [Terraform](https://learn.hashicorp.com/tutorials/terraform/install-cli?in=terraform/aws-get-started) installed

## Deployment Instructions

1. Create a new directory, navigate to that directory in a terminal and clone the GitHub repository:
    ``` 
    git clone https://github.com/aws-samples/serverless-patterns
    ```
1. Change directory to the pattern directory:
    ```
    cd step-function-lambda-terraform
    ```
1. From the command line, initialize terraform to download and installs the providers defined in the configuration:
    ```
    terraform init
    ```
1. From the command line, apply the configuration in the main.tf file:
    ```
    terraform apply
    ```
1. During the prompts:
    * Enter yes
1. Note the outputs from the deployment process. These contain the resource names and/or ARNs which are used for testing.

## How it works

The AWS Cloudwatch rule is configured to start a Step Function execution every 10 minutes. The Step function then invokes a AWS Lambda with the default payload.
The payload, Lambda function definition and the event rule can be modified as per requirement.

## Testing

After deployment, go to the cloudwatch logs to check the event details.
## Cleanup

1. Change directory to the pattern directory:
    ```
    cd step-function-lambda-terraform
    ```
1. Delete all created resources
    ```bash
    terraform apply -destroy
    ```
1. During the prompts:
    * Enter yes
1. Confirm all created resources has been deleted
    ```bash
    terraform show
    ```
    ```
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