template.prod.yaml

AWSTemplateFormatVersion: "2010-09-09"
Description: >-
  shopify-bot

Transform:
  - AWS::Serverless-2016-10-31

Globals:
  Function:
    Environment:
      Variables:
        Region: 'us-east-1'
    Runtime: nodejs18.x
    MemorySize: 128 # MB
    Timeout: 6 # optional, in seconds, default is 6

Resources:

  ConfigFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: lambdas/config
      Handler: index.handler
      Architectures:
        - x86_64
      Description: Stores Shopify sites and Discord webhook parameters (excluding the secure API key - that is stored in Secrets Manager)
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref ConfigTable
      Environment:
        Variables:
          # The ConfigTable stores the list of Shopify sites that the ShopifySyncFunction will check
          CONFIG_TABLE: !Ref ConfigTable
      Events:
        Api:
          Type: Api
          Properties:
            Path: /config
            Method: POST

  ShopifySyncFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: lambdas/shopifySync
      Handler: index.handler
      Timeout: 15
      Architectures:
        - x86_64
      Description: Scans Shopify sites and writes updates to a DynamoDB table
      Policies:
        # Give Create/Read/Update/Delete Permissions to the InventoryTable
        - DynamoDBCrudPolicy:
            TableName: !Ref InventoryTable
        - DynamoDBCrudPolicy:
            TableName: !Ref ConfigTable
      Environment:
        Variables:
          # The ConfigTable stores the list of Shopify sites that the ShopifySyncFunction will check
          CONFIG_TABLE: !Ref ConfigTable
          # The InventoryTable stores the product/stock items that were retrieved from the sites
          INVENTORY_TABLE: !Ref InventoryTable
      Events:
        Api:
          Type: Api
          Properties:
            Path: /sync
            Method: POST
        Schedule:
          Type: Schedule
          Properties:
            Schedule: rate(5 minutes)
            Name: ShopifySyncSchedule
            Description: Schedules the ShopifySyncFunction to run every 5 minutes
            Enabled: true
            RetryPolicy:
              MaximumEventAgeInSeconds: 86400
              MaximumRetryAttempts: 185

  QueuePublisherFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: lambdas/queuePublisher
      Handler: index.handler
      Architectures:
        - x86_64
      Policies:
        - Statement:
            # Adds the necessary permissions for the Lambda function to write to the SQS queue
            - Effect: Allow
              Action:
                - sqs:SendMessage
              Resource: !GetAtt InventoryUpdateQueue.Arn
      Description: |2
        Receives DynamoDB event streams from the InventoryTable and decides whether a Discord message should be sent. If
        so, then craft notify the SNS Topic. DiscordNotifierFunction subscribes and sends messages from the queue.
      Environment:
        Variables:
          QUEUE_URL: !Ref InventoryUpdateQueue
      Events:
        StreamEvent:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt InventoryTable.StreamArn
            StartingPosition: TRIM_HORIZON
            BatchSize: 1
            Enabled: true

  DiscordNotifierFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: lambdas/discordNotifier
      Handler: index.handler
      Architectures:
        - x86_64
      Description: Sends a Discord notification when a product is available
      Policies:
        - AWSSecretsManagerGetSecretValuePolicy:
            # Grants read access to Secrets Manager; used to retrieve Discord API key
            SecretArn: !Ref DiscordApiKey
      Environment:
        Variables:
          DISCORD_SECRET_ARN: !Ref DiscordApiKey
          QUEUE_URL: !Ref InventoryUpdateQueue
      Events:
        Api:
          Type: Api
          Properties:
            Path: /
            Method: POST
        SQSEvent:
          Type: SQS
          Properties:
            Queue: !GetAtt InventoryUpdateQueue.Arn

  InventoryUpdateQueue:
    Type: AWS::SQS::Queue
    Properties:
      FifoQueue: true
      QueueName: InventoryUpdateQueue.fifo
      ContentBasedDeduplication: true

  ConfigTable:
    Type: AWS::DynamoDB::Table
    Properties:
      AttributeDefinitions:
        - AttributeName: name
          AttributeType: S
      KeySchema:
        - AttributeName: name
          KeyType: HASH
      StreamSpecification:
        StreamViewType: NEW_AND_OLD_IMAGES
      ProvisionedThroughput:
        ReadCapacityUnits: 2
        WriteCapacityUnits: 2

  InventoryTable:
    Type: AWS::DynamoDB::Table
    Properties:
      AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
      KeySchema:
        - AttributeName: id
          KeyType: HASH
      StreamSpecification:
        StreamViewType: NEW_AND_OLD_IMAGES
      ProvisionedThroughput:
        ReadCapacityUnits: 9
        WriteCapacityUnits: 9

  DiscordApiKey:
    Type: AWS::SecretsManager::Secret
    Properties:
      Description: 'This is the sensitive hash value that comes after "api/hooks/" in the Discord API key'
      Name: DiscordApiKey
      SecretString: '{"discord-api-key":"this-is-not-a-valid-key-please-replace"}'

Outputs:
  WebEndpoint:
    Description: "API Gateway endpoint URL for Prod stage"
    Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/"