serverless.yml

service: kinesis-autoscaler

custom:
  scaleUpTopicName: ${self:service}-scale-up-${self:provider.stage}
  scaleDownTopicName: ${self:service}-scale-down-${self:provider.stage}
  autoscalerLogsTableName: ${self:service}-logs-${self:provider.stage}

provider:
  name: aws
  runtime: python3.9
  region: ${opt:region, 'us-east-1'}
  stage: ${opt:stage, 'dev'}
  memorySize: 1024
  timeout: 30
  environment:
    STAGE: ${self:provider.stage}

  iamRoleStatements:
    - Effect: Allow
      Action:
        - kinesis:UpdateShardCount
        - kinesis:DescribeStreamSummary
      Resource: '*'
    - Effect: Allow
      Action:
        - cloudwatch:DescribeAlarms
        - cloudwatch:PutMetricAlarm
        - cloudwatch:SetAlarmState
        - cloudwatch:GetMetricData
      Resource: '*'
    - Effect: Allow
      Action:
        - dynamodb:PutItem
        - dynamodb:DescribeTable
      Resource:
        - Fn::GetAtt:
            - AutoscalerLogsTable
            - Arn

functions:
  scale-up:
    description: 'Scales up Kinesis data stream'
    handler: handler.scale_up
    events:
      - sns:
          arn:
            Ref: ScaleUpTopic
          topicName: ${self:custom.scaleUpTopicName}

  scale-down:
    description: 'Scales down Kinesis data stream'
    handler: handler.scale_down
    events:
      - sns:
          arn:
            Ref: ScaleDownTopic
          topicName: ${self:custom.scaleDownTopicName}

resources:
  Resources:
    ScaleUpTopic:
      Type: AWS::SNS::Topic
      Properties:
        DisplayName: ${self:custom.scaleUpTopicName}
        TopicName: ${self:custom.scaleUpTopicName}

    ScaleDownTopic:
      Type: AWS::SNS::Topic
      Properties:
        DisplayName: ${self:custom.scaleDownTopicName}
        TopicName: ${self:custom.scaleDownTopicName}

    AutoscalerLogsTable:
      Type: AWS::DynamoDB::Table
      Properties:
        TableName: ${self:custom.autoscalerLogsTableName}
        BillingMode: PAY_PER_REQUEST
        AttributeDefinitions:
          - AttributeName: stream_name
            AttributeType: S
          - AttributeName: scaling_datetime
            AttributeType: S
        KeySchema:
          - AttributeName: stream_name
            KeyType: HASH
          - AttributeName: scaling_datetime
            KeyType: RANGE
        TimeToLiveSpecification:
          AttributeName: expiration_datetime
          Enabled: true

  Outputs:
    ScaleUpTopicArn:
      Value:
        Ref: ScaleUpTopic
      Export:
        Name: ScaleUpTopicArn-${self:provider.stage}

    ScaleDownTopicArn:
      Value:
        Ref: ScaleDownTopic
      Export:
        Name: ScaleDownTopicArn-${self:provider.stage}

plugins:
  - serverless-python-requirements