template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  sutd-trivia-bot

# More info about Globals: https://github.com/awslabs/serverless-application-model/blob/master/docs/globals.rst
Parameters:
  BotToken:
    Type: String
    Description: Telegram API bot token

Globals:
  Function:
    Timeout: 15
    Runtime: python3.8
    Environment:
      Variables:
        TABLE_NAME: !Ref GameTable
        LOCK_TABLE_NAME: !Ref LockTable
        BOT_TOKEN: !Ref BotToken
    Layers:
      - !Ref CommonLayer
    EventInvokeConfig:
      MaximumRetryAttempts: 0

Resources:
  CommonLayer:
    Type: AWS::Serverless::LayerVersion
    Properties:
      ContentUri: common
      CompatibleRuntimes:
        - python3.8
    Metadata:
      BuildMethod: python3.8
  LockTable:
    Type: AWS::DynamoDB::Table
    Properties:
      KeySchema:
        - AttributeName: "lock_key"
          KeyType: "HASH"
        - AttributeName: "sort_key"
          KeyType: "RANGE"
      AttributeDefinitions:
        - AttributeName: "lock_key"
          AttributeType: "S"
        - AttributeName: "sort_key"
          AttributeType: "S"
      BillingMode: PAY_PER_REQUEST
      TimeToLiveSpecification:
        AttributeName: expiry_time
        Enabled: true
  GameTable:
    Type: AWS::DynamoDB::Table
    Properties:
      KeySchema:
        - AttributeName: "pk"
          KeyType: "HASH"
        - AttributeName: "sk"
          KeyType: "RANGE"
      AttributeDefinitions:
        - AttributeName: "pk"
          AttributeType: "S"
        - AttributeName: "sk"
          AttributeType: "S"
        - AttributeName: "score"
          AttributeType: "N"
        - AttributeName: "gsi_current_active_question"
          AttributeType: "S"
        - AttributeName: "gsi_callback_question_id"
          AttributeType: "S"
      GlobalSecondaryIndexes:
        - IndexName: ScoreBoard
          KeySchema:
            - AttributeName: "pk"
              KeyType: "HASH"
            - AttributeName: "score"
              KeyType: "RANGE"
          Projection:
            ProjectionType: ALL
        - IndexName: CurrentActiveQuestion
          KeySchema:
            - AttributeName: "pk"
              KeyType: "HASH"
            - AttributeName: "gsi_current_active_question"
              KeyType: "RANGE"
          Projection:
            ProjectionType: ALL
        - IndexName: CallbacksByQuestionId
          KeySchema:
            - AttributeName: "pk"
              KeyType: "HASH"
            - AttributeName: "gsi_callback_question_id"
              KeyType: "RANGE"
          Projection:
            ProjectionType: ALL
      BillingMode: PAY_PER_REQUEST
  TelegramBotFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: bot
      Handler: lambda_entry.lambda_handler
      Events:
        JoinSession:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /
            Method: post
            RestApiId: !Ref TelegramWebhookAPI
      Environment:
        Variables:
          TABLE_NAME: !Ref GameTable
          LOCK_TABLE_NAME: !Ref LockTable
          START_GAME_STATE_MACHINE_ARN: !Ref QuizFlowStateMachine
      EventInvokeConfig:
        MaximumRetryAttempts: 0
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref LockTable
        - DynamoDBCrudPolicy:
            TableName: !Ref GameTable
        - Statement:
            - Effect: Allow
              Action:
                - 'states:StopExecution'
                - 'states:StartExecution'
              Resource:
                - !Sub "arn:${AWS::Partition}:states:${AWS::Region}:${AWS::AccountId}:stateMachine:*"
                - !Sub
                  - "arn:${Partition}:states:${Region}:${Account}:execution:${StateMachineName}:*"
                  - Partition: !Ref AWS::Partition
                    Region: !Ref AWS::Region
                    Account: !Ref AWS::AccountId
                    StateMachineName: !GetAtt QuizFlowStateMachine.Name
                - !Sub
                  - "arn:${Partition}:states:${Region}:${Account}:execution:${StateMachineName}:*"
                  - Partition: !Ref AWS::Partition
                    Region: !Ref AWS::Region
                    Account: !Ref AWS::AccountId
                    StateMachineName: !GetAtt QuestionFlowStateMachine.Name
  TelegramWebhookAPI:
    Type: AWS::Serverless::Api
    Properties:
      Name: !Sub "${AWS::StackName}-TelegramWebhookAPI"
      StageName: prod
      EndpointConfiguration:
        Type: REGIONAL

  ### Question Flow Section
  QuestionFlowSendQuestionFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: quizzer/question_flow/send_question
      Handler: send.lambda_handler
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref GameTable
        - DynamoDBCrudPolicy:
            TableName: !Ref LockTable
  QuestionFlowFailQuestionFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: quizzer/question_flow/fail_question
      Handler: fail.lambda_handler
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref GameTable
        - DynamoDBCrudPolicy:
            TableName: !Ref LockTable
  QuestionFlowStateMachine:
    Type: AWS::Serverless::StateMachine
    Properties:
      DefinitionUri: quizzer/question_flow/statemachine.asl.json
      DefinitionSubstitutions:
        SendQuestionFunctionArn: !GetAtt QuestionFlowSendQuestionFunction.Arn
        FailQuestionFunctionArn: !GetAtt QuestionFlowFailQuestionFunction.Arn
      Policies:
        - LambdaInvokePolicy:
            FunctionName: !Ref QuestionFlowSendQuestionFunction
        - LambdaInvokePolicy:
            FunctionName: !Ref QuestionFlowFailQuestionFunction

  ### Parent Quiz Flow Section
  QuizFlowSampleQuestionsFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: quizzer/quiz_flow/sample_questions
      Handler: sample.lambda_handler
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref GameTable
        - DynamoDBCrudPolicy:
            TableName: !Ref LockTable
  QuizFlowChooseQuestionFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: quizzer/quiz_flow/choose_question
      Handler: choose.lambda_handler
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref GameTable
        - DynamoDBCrudPolicy:
            TableName: !Ref LockTable
  QuizFlowEndQuizFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: quizzer/quiz_flow/end_quiz
      Handler: end.lambda_handler
      Environment:
        Variables:
          START_GAME_STATE_MACHINE_ARN: "To replace later"
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref GameTable
        - DynamoDBCrudPolicy:
            TableName: !Ref LockTable
  QuizFlowIntermissionFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: quizzer/quiz_flow/intermission
      Handler: intermission.lambda_handler
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref GameTable
        - DynamoDBCrudPolicy:
            TableName: !Ref LockTable
  QuizFlowStateMachine:
    Type: AWS::Serverless::StateMachine
    Properties:
      DefinitionUri: quizzer/quiz_flow/statemachine.asl.json
      DefinitionSubstitutions:
        SampleQuestionsFunctionArn: !GetAtt QuizFlowSampleQuestionsFunction.Arn
        ChooseQuestionFunctionArn: !GetAtt QuizFlowChooseQuestionFunction.Arn
        EndQuizFunctionArn: !GetAtt QuizFlowEndQuizFunction.Arn
        IntermissionFunctionArn: !GetAtt QuizFlowIntermissionFunction.Arn
        QuestionFlowStateMachineArn: !Ref QuestionFlowStateMachine
      Policies:
        - LambdaInvokePolicy:
            FunctionName: !Ref QuizFlowSampleQuestionsFunction
        - LambdaInvokePolicy:
            FunctionName: !Ref QuizFlowChooseQuestionFunction
        - LambdaInvokePolicy:
            FunctionName: !Ref QuizFlowIntermissionFunction
        - LambdaInvokePolicy:
            FunctionName: !Ref QuizFlowEndQuizFunction
        - StepFunctionsExecutionPolicy:
            StateMachineName: !Sub
              - "${QuestionFlowStateMachineName}"
              - QuestionFlowStateMachineName: !GetAtt QuestionFlowStateMachine.Name
        - Statement:
          - Effect: Allow
            Action:
              - states:DescribeExecution
              - states:StopExecution
            Resource:
              - "*"
          - Effect: Allow
            Action:
              - events:PutTargets
              - events:PutRule
              - events:DescribeRule
            Resource:
            - !Sub arn:${AWS::Partition}:events:${AWS::Region}:${AWS::AccountId}:rule/StepFunctionsGetEventsForStepFunctionsExecutionRule
Outputs:
  TelegramWebhookURL:
    Description: Set the bot's API webhook to this location
    Value: !Sub "https://${TelegramWebhookAPI}.execute-api.${AWS::Region}.amazonaws.com/prod"
  GameTableName:
    Value: !Ref GameTable
  LockTableName:
    Value: !Ref LockTable