serverless.yml

service: sls-sm-21

plugins:
  - serverless-step-functions

frameworkVersion: '2'

provider:
  name: aws
  runtime: nodejs14.x
  lambdaHashingVersion: 20201221
  stage: dev
  region: eu-central-1
  environment:
    BITCOIN_LEDGER: { "Ref": "BitcoinLedger" }
    PENDING_TRANSACTIONS_TABLE: { "Ref": "PendingTransactionsTable" }
  iamRoleStatements:
    - Effect: Allow
      Action:
        - states:SendTaskSuccess
        - states:StartExecution
      Resource: "*" # Because of circular dependencies
    - Effect: Allow
      Action:
        - dynamodb:PutItem
        - dynamodb:GetItem
        - dynamodb:DeleteItem
      Resource: { "Fn::GetAtt": ["PendingTransactionsTable", "Arn"] }
    - Effect: Allow
      Action:
        - dynamodb:Scan
        - dynamodb:DeleteItem
      Resource: { "Fn::GetAtt": ["BitcoinLedger", "Arn"] }

functions:
  pullLedgerData:
    handler: src/pullLedgerData.handler
    events:
      - schedule: rate(5 minutes)
  createOrder:
    handler: src/createOrder.handler
    environment:
      PROCESS_ORDER_SM: { "Ref": "ProcessOrderStepFunctionsStateMachine" }
    events:
      - http:
          path: order
          method: PUT
  generateAddress:
    handler: src/generateAddress.handler
  waitForBlocks:
    handler: src/waitForBlocks.handler
  shipOrder:
    handler: src/shipOrder.handler

stepFunctions:
  validate: true
  stateMachines:
    processOrder:
      definition:
        StartAt: Generate Bitcoin address QR code
        States:
          Generate Bitcoin address QR code:
            Type: Task
            Resource: arn:aws:states:::lambda:invoke
            OutputPath: "$.Payload"
            Parameters:
              FunctionName: { "Ref": "generateAddress" }
              Payload.$: "$"
            Next: Wait for 10 block confirmations
          Wait for 10 block confirmations:
            Type: Task
            Resource: arn:aws:states:::lambda:invoke.waitForTaskToken
            Parameters:
              FunctionName: { "Ref": "waitForBlocks" }
              Payload:
                input.$: "$"
                taskToken.$: "$$.Task.Token"
            Next: Ship customer's order
          Ship customer's order:
            Type: Task
            Resource: arn:aws:states:::lambda:invoke
            OutputPath: "$.Payload"
            Parameters:
              FunctionName: { "Ref": "shipOrder" }
              Payload.$: "$"
            End: true

resources:
 Resources:
  BitcoinLedger:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: bitcoin-ledger
      AttributeDefinitions:
        - AttributeName: blockHash
          AttributeType: S
      KeySchema:
        - AttributeName: blockHash
          KeyType: HASH
      BillingMode: PAY_PER_REQUEST
  PendingTransactionsTable:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: pending-transactions
      AttributeDefinitions:
        - AttributeName: address
          AttributeType: S
      KeySchema:
        - AttributeName: address
          KeyType: HASH
      BillingMode: PAY_PER_REQUEST