AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
   SAM Template for Resilient Cloudformation custom resource deployment

# More info about Globals: https://github.com/awslabs/serverless-application-model/blob/master/docs/globals.rst
Globals:
  Function:
    Timeout: 3
Parameters:
  InstanceType:
    Description: EC2 instance type
    Type: String
    Default: t2.micro
    AllowedValues:
      - t2.micro
      - t2.small
      - t2.medium
      - m1.small
      - m1.large
      - m1.medium
      - m1.xlarge
    ConstraintDescription: Must be a valid EC2 instance type.

Mappings:
  AWSInstanceType2Arch:
    t2.micro:
      "Arch" : "HVM64"
    t2.small:
      "Arch" : "HVM64"
    t2.medium:
      "Arch" : "HVM64"
    m1.small:
      "Arch" : "PV64"
    m1.medium:
      "Arch" : "PV64"
    m1.large:
      "Arch": "PV64"
    m1.xlarge:
      "Arch" : "PV64"

Resources:
  AMIInfoFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: amilookup/
      Handler: app.lambda_handler
      Runtime: python3.8
      Timeout: 300
      EventInvokeConfig:
          MaximumEventAgeInSeconds: 60
          MaximumRetryAttempts: 2
          DestinationConfig:
            OnFailure:
              Type: SQS
              Destination: !GetAtt RetryQueue.Arn
      Policies:
        - AMIDescribePolicy: {}
  AMIInfo:
    Type: Custom::AMIInfo
    DependsOn: RetryFunction
    Properties:
      ServiceToken: !GetAtt AMIInfoFunction.Arn
      Region: !Ref "AWS::Region"
      Architecture:
        Fn::FindInMap:
          - AWSInstanceType2Arch
          - !Ref InstanceType
          - Arch

  TestInstance:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: !Ref InstanceType
      ImageId: !GetAtt AMIInfo.Id

  RetryFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: retry/
      Handler: app.lambda_handler
      Runtime: python3.8
      Timeout: 60
      Events:
        MySQSEvent:
          Type: SQS
          Properties:
            Queue: !GetAtt RetryQueue.Arn
            BatchSize: 1
      Policies:
        - LambdaInvokePolicy:
            FunctionName: !Ref AMIInfoFunction

  RetryQueue:
    Type: AWS::SQS::Queue
    Properties:
      VisibilityTimeout: 60
      DelaySeconds: 60
      MessageRetentionPeriod: 600


Outputs:
  # ServerlessRestApi is an implicit API created out of Events key under Serverless::Function
  # Find out more about other implicit resources you can reference within SAM
  # https://github.com/awslabs/serverless-application-model/blob/master/docs/internals/generated_resources.rst#api
  AMIInfoFunction:
    Description: "Ami lookup Lambda Function ARN"
    Value: !GetAtt AMIInfoFunction.Arn
  AMIInfoFunctionIamRole:
    Description: "Implicit IAM Role created for Ami lookup function"
    Value: !GetAtt AMIInfoFunctionRole.Arn