simple_step_function.yaml

# simple_stack.yaml
# AWS Cloudformation example for data pipeline
AWSTemplateFormatVersion: '2010-09-09'
Description: An example template for a Step Functions state machine.
Resources:
  LambdaExecutionRole:
    Type: "AWS::IAM::Role"
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: "sts:AssumeRole"

  MyLambdaFunction:
    Type: "AWS::Lambda::Function"
    Properties:
      Handler: "index.handler"
      Role: !GetAtt [ LambdaExecutionRole, Arn ]
      Code:
        ZipFile: |
          exports.handler = (event, context, callback) => {
              callback(null, "Hello World!");
          };
      Runtime: "nodejs12.x"
      Timeout: "25"

  StatesExecutionRole:
    Type: "AWS::IAM::Role"
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: "Allow"
            Principal:
              Service:
                - !Sub states.${AWS::Region}.amazonaws.com
            Action: "sts:AssumeRole"
      Path: "/"
      Policies:
        - PolicyName: StatesExecutionPolicy
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
              - Effect: Allow
                Action:
                  - "lambda:InvokeFunction"
                Resource: "*"

  MyStateMachine:
    Type: AWS::StepFunctions::StateMachine
    Properties:
      StateMachineName: HelloWorld-StateMachine
      DefinitionString:
        !Sub
          - |-
            {
              "Comment": "A Hello World example using an AWS Lambda function",
              "StartAt": "HelloWorld",
              "States": {
                "HelloWorld": {
                  "Type": "Task",
                  "Resource": "${lambdaArn}",
                  "End": true
                }
              }
            }
          - {lambdaArn: !GetAtt [ MyLambdaFunction, Arn ]}
      RoleArn: !GetAtt [ StatesExecutionRole, Arn ]
      Tags:
        -
          Key: "keyname1"
          Value: "value1"
        -
          Key: "keyname2"
          Value: "value2"