serverless.yml

service: delivery-serverless-aws

provider:
  name: aws
  runtime: nodejs12.x
  region: us-east-1
  environment:
    REGION: ${self:provider.region}
    PENDING_ORDER_QUEUE:
      Ref: PendingOrdersQueue
    PENDING_ORDER_QUEUE_NAME: PendingOrdersQueue
    COMPLETED_ORDER_TABLE: CompletedOrderTable

  iamRoleStatements:
    - Effect: "Allow"
      Action:
        - "sqs:SendMessage"
      Resource: "arn:aws:sqs:${self:provider.region}:*:${self:provider.environment.PENDING_ORDER_QUEUE_NAME}"
    - Effect: "Allow"
      Action:
        - "dynamodb:GetItem"
        - "dynamodb:PutItem"
        - "dynamodb:UpdateItem"
        - "dynamodb:DeleteItem"
      Resource:
        - "arn:aws:dynamodb:${self:provider.region}:*:table/${self:provider.environment.COMPLETED_ORDER_TABLE}"

functions:
  # This function is triggered by a POST http request with the order information.
  makeOrder:
    handler: handler.makeOrder
    events:
      - http:
          method: post
          path: order
          cors: true

  # This function is triggered when 1 element is enqueued in a queue called PendingOrdersQueue.
  prepareOrder:
    handler: handler.prepareOrder
    events:
      - sqs:
          arn:
            Fn::GetAtt:
              - PendingOrdersQueue
              - Arn
          batchSize: 1

  # This function is triggered when 3 elements are inserted in the table CompletedOrdersTable in DynamoDB.
  sendOrder:
    handler: handler.sendOrder
    events:
      - stream:
          type: dynamodb
          batchSize: 3
          startingPosition: LATEST
          arn:
            Fn::GetAtt:
              - CompletedOrdersTable
              - StreamArn

  # This function is triggered by a GET http request with the order ID.
  getOrderStatus:
    handler: handler.getOrderStatus
    events:
      - http:
          method: get
          path: order/{orderId}
          cors: true

resources:
  Resources:
    PendingOrdersQueue:
      Type: "AWS::SQS::Queue"
      Properties:
        QueueName: ${self:provider.environment.PENDING_ORDER_QUEUE_NAME}
    CompletedOrdersTable:
      Type: "AWS::DynamoDB::Table"
      Properties:
        AttributeDefinitions:
        - AttributeName: "orderId"
          AttributeType: "S"
        KeySchema:
        - AttributeName: "orderId"
          KeyType: "HASH"
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1
        TableName: ${self:provider.environment.COMPLETED_ORDER_TABLE}
        StreamSpecification:
          StreamViewType: NEW_IMAGE