Amazon Interactive Video Service が生成するアーカイブから不要な解像度セグメントを自動削除するためのステートマシンを作ってみた

AWSTemplateFormatVersion: "2010-09-09"
Description: "A template for automation to delete unnecessary ivs archive rendition."
Parameters:
  # 作成リソースに付与する接頭語
  Prefix:
    Description: "Prefix of each resource"
    Type: "String"
    Default: "sample"
  # IVS のアーカイブ保存先バケット名
  BucketName:
    Description: "Target Bucket name to delete ivs archive"
    Type: "String"
  # 削除するレンディション
  DeleteRendition:
    Description: "Target Rendition to delete ivs archive"
    Type: "String"
    Default: "160p30"
    AllowedValues:
      - "1080p"
      - "720p30"
      - "480p30"
      - "360p30"
      - "160p30"

Resources:
  # Step Functions StateMachine
  StateMachine:
    Type: "AWS::StepFunctions::StateMachine"
    Properties:
      StateMachineName: !Sub "${Prefix}-delete-ivs-archive-statemachine"
      DefinitionS3Location:
        Bucket: "<Step Functions ステートマシンの定義ファイル保存先 S3 バケット名>"
        Key: "delete-ivs-archive-sample.json"
      DefinitionSubstitutions:
        DeleteRendition: !Ref DeleteRendition
        BucketName: !Ref BucketName
      RoleArn: !GetAtt StateMachineRole.Arn
      Tags:
        - Key: "Name"
          Value: !Sub "${Prefix}-delete-ivs-archive-statemachine"
  ## IAM Role for StateMachie
  StateMachineRole:
    Type: "AWS::IAM::Role"
    Properties:
      RoleName: !Sub "${Prefix}-delete-ivs-archive-statemachine-role"
      Path: "/service-role/"
      AssumeRolePolicyDocument:
        Statement:
          - Effect: "Allow"
            Principal:
              Service:
                - "states.amazonaws.com"
            Action:
              - "sts:AssumeRole"
      ManagedPolicyArns:
        - !Ref DeleteIVSArchivePolicy
  ## IAM Policy for DeleteIVSArchive
  DeleteIVSArchivePolicy:
    Type: "AWS::IAM::ManagedPolicy"
    Properties:
      ManagedPolicyName: !Sub "${Prefix}-delete-ivs-archive-policy"
      Path: "/service-role/"
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: "Allow"
            Action:
              - "s3:ListBucket"
            Resource:
              - !Join
                - ""
                - - "arn:aws:s3:::"
                  - !Ref BucketName
          - Effect: "Allow"
            Action:
              - "s3:DeleteObject"
            Resource:
              - !Join
                - ""
                - - "arn:aws:s3:::"
                  - !Ref BucketName
                  - "/*"
  # EventRule for CreateManagedAccount
  EventRule:
    Type: "AWS::Events::Rule"
    Properties:
      Description: "Catch 'Finish IVS Recording' event"
      EventPattern: |-
        {
          "source": ["aws.ivs"],
          "detail-type": ["IVS Recording State Change"],
          "detail": {
            "recording_status": ["Recording End"]
          }
        }
      Name: !Sub "${Prefix}-catch-FinishIVSRecording"
      State: "ENABLED"
      Targets:
        - Arn: !Ref StateMachine
          Id: !Sub "${Prefix}-delete-ivs-archive-statemachine"
          RoleArn: !GetAtt EventBridgeRole.Arn
  ## IAM Role for EventBridge
  EventBridgeRole:
    Type: "AWS::IAM::Role"
    Properties:
      RoleName: !Sub "${Prefix}-catch-FinishIVSRecording-role"
      Path: "/service-role/"
      AssumeRolePolicyDocument:
        Statement:
          - Effect: "Allow"
            Principal:
              Service:
                - "events.amazonaws.com"
            Action:
              - "sts:AssumeRole"
      ManagedPolicyArns:
        - !Ref InvokeStepFunctionsPolicy
  ## IAM Policy to invoke Step Functions
  InvokeStepFunctionsPolicy:
    Type: "AWS::IAM::ManagedPolicy"
    Properties:
      ManagedPolicyName: !Sub "${Prefix}-invoke-step-functions-from-eventbridge-policy"
      Path: "/service-role/"
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Resource:
              - !Ref StateMachine
            Effect: "Allow"
            Action:
              - "states:StartExecution"

{
    "Comment": "This is your state machine",
    "StartAt": "ListObjectsV2",
    "States": {
        "ListObjectsV2": {
            "Type": "Task",
            "Next": "Map",
            "Parameters": {
                "Bucket": "${BucketName}",
                "Prefix.$": "States.Format('{}/media/hls/${DeleteRendition}', $.recording_s3_key_prefix)",
                "MaxKeys": 100
            },
            "Resource": "arn:aws:states:::aws-sdk:s3:listObjectsV2",
            "InputPath": "$.detail",
            "ResultPath": "$.listresult"
        },
        "Map": {
            "Type": "Map",
            "Iterator": {
                "StartAt": "Pass",
                "States": {
                    "Pass": {
                        "Type": "Pass",
                        "End": true,
                        "Parameters": {
                            "Key.$": "$.Key"
                        }
                    }
                }
            },
            "ItemsPath": "$.listresult.Contents",
            "Next": "DeleteObjects",
            "ResultPath": "$.mapresult"
        },
        "DeleteObjects": {
            "Type": "Task",
            "Parameters": {
                "Bucket": "${BucketName}",
                "Delete": {
                    "Objects.$": "$.mapresult"
                }
            },
            "Resource": "arn:aws:states:::aws-sdk:s3:deleteObjects",
            "ResultPath": "$.deleteresult",
            "Next": "Choice"
        },
        "Choice": {
            "Type": "Choice",
            "Choices": [
                {
                    "Variable": "$.listresult.IsTruncated",
                    "BooleanEquals": true,
                    "Next": "ListObjectsV2"
                }
            ],
            "Default": "Finish"
        },
        "Finish": {
            "Type": "Pass",
            "End": true,
            "InputPath": "$.deleteresult"
        }
    }
}