Closed2023/12/03にクローズ5

【AWS】StepFunctionsを試す

なに

フローを視覚的に管理できるツール。
複数のAWSサービス間でのタスクの自動化や連携を簡単に設計、実行、管理することができる

ユースケース

エラー処理が便利そう

以下が初心者に優しそうなので参考にさせていただく

メモ

ステートマシン①

{
    "Comment": "Sample AWS Step functions flow",
    "StartAt": "TaskSampleCall",
    "States": {
        "TaskSampleCall": {
            "Comment": "SampleCallの呼び出し",
            "Type": "Task",
            "Resource": "arn:aws:lambda:ap-northeast-1:(AWSユーザーID):function:SampleCall",
            "InputPath": "$",
            "ResultPath": "$.SampleCallResult",
            "OutputPath": "$",
            "End": true
        }
    }
}

type：ステートマシンによって実行される単一の作業単位を表す。Taskの場合LambdaだったりAWSサービスを実行可能
- https://docs.aws.amazon.com/ja_jp/step-functions/latest/dg/supported-services-awssdk.html#supported-services-awssdk-list
InputPath：タスクに渡す入力データのJSONパスを指定。"$"は全ての入力データをそのままタスクに渡すことを意味する。
- OutputPathも同様の考え

飽きた...

すぐに戻ってこれるようにterraformコードに起こした
副産物のLambdaモジュールは複数Lambdaを立ち上げることが出来て便利

Lambdaモジュール

階層

階層

├── lambda_function
│   ├── lambda1
│   │   └── lambda1.py
│   ├── lambda2
│   │   └── lambda2.py
│   └── lambda3
│       └── lambda3.py
├── lambda.tf
└── variables.tf

lambda.tf

lambda.tf

data "archive_file" "lambda" {
  type        = "zip"
  source_dir  = "${path.module}/lambda_function/${var.lambda_env}"
  output_path = "${path.module}/${var.lambda_env}.zip"
}

resource "aws_lambda_function" "lambda" {
  function_name    = var.lambda_env
  handler          = "${var.lambda_env}.lambda_handler"
  runtime          = "python3.11"
  filename         = data.archive_file.lambda.output_path
  source_code_hash = filebase64sha256(data.archive_file.lambda.output_path)
  role = aws_iam_role.lambda.arn
}

resource "aws_iam_role" "lambda" {
  name = "${var.lambda_env}-role"
  assume_role_policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": "sts:AssumeRole",
      "Principal": {
        "Service": "lambda.amazonaws.com"
      },
      "Effect": "Allow",
      "Sid": ""
    }
  ]
}
EOF
}

resource "aws_iam_policy" "lambda" {
  name =  "${var.lambda_env}-policy"
  description = "IAM policy for the ${var.lambda_env}"

  policy = jsonencode({
    Version   = "2012-10-17"
    Statement = [
      {
        Effect   = "Allow"
        Action   = [
          "logs:CreateLogGroup",
          "logs:CreateLogStream",
          "logs:PutLogEvents"
        ]
        Resource = [
          aws_cloudwatch_log_group.lambda.arn,
          "${aws_cloudwatch_log_group.lambda.arn}:*"
        ]
      }
    ]
  })
}

resource "aws_iam_role_policy_attachment" "lambda" {
  role       = aws_iam_role.lambda.name
  policy_arn = aws_iam_policy.lambda.arn
}

resource "aws_cloudwatch_log_group" "lambda" {
  name = "/aws/lambda/${aws_lambda_function.lambda.function_name}"
  retention_in_days = 1
}

main.tf

module "test-multi-lambda" {
  for_each = toset(["lambda1", "lambda2", "lambda3"])
  source = "./modules/test-multi-lambda"
  env = var.env
  lambda_env = each.key
}

step functions

stepfunctions

main.tf

### IAM周り
resource "aws_iam_role" "step_functions" {
  name = "StepFunctionsLambdaExecRole"

  assume_role_policy = jsonencode({
    Version = "2012-10-17",
    Statement = [
      {
        Action = "sts:AssumeRole",
        Effect = "Allow",
        Principal = {
          Service = "states.amazonaws.com"
        }
      },
    ]
  })
}

resource "aws_iam_role_policy" "step_functions" {
  name = "StepFunctionsLambdaPolicy"
  role = aws_iam_role.step_functions.id

  policy = jsonencode({
    Version = "2012-10-17",
    Statement = [
      {
        Action = [
          "lambda:InvokeFunction"
        ],
        Effect = "Allow",
        Resource = [
            "*"
        ]
      },
    ]
  })
}

### state machine
resource "aws_sfn_state_machine" "step_functions" {
  name     = "SampleCalculationFlow"
  role_arn = aws_iam_role.step_functions.arn

  definition = <<EOF
{
    "Comment": "Sample Calculation flow",
    "StartAt": "TaskInitialSetting",
    "States": {
        "TaskInitialSetting": {
            "Comment": "初期の値を設定します",
            "Type": "Task",
            "Resource": "arn:aws:lambda:ap-northeast-1:${local.account_id}:function:lambda1",
            "InputPath": "$",
            "ResultPath": "$.SettingResult",
            "OutputPath": "$",
            "Next": "TaskAddition"
        },
        "TaskAddition": {
            "Comment": "足し算をおこないます",
            "Type": "Task",
            "Resource": "arn:aws:lambda:ap-northeast-1:${local.account_id}:function:lambda2",
            "InputPath": "$",
            "ResultPath": "$.AdditionResult",
            "OutputPath": "$",
            "Next": "TaskMultiply"
        },
        "TaskMultiply": {
            "Comment": "掛け算をおこないます",
            "Type": "Task",
            "Resource": "arn:aws:lambda:ap-northeast-1:${local.account_id}:function:lambda3",
            "InputPath": "$",
            "ResultPath": "$.MultiplyResult",
            "OutputPath": "$",
            "End": true
        }
    }
}
EOF
}

このスクラップは2023/12/03にクローズされました