serverless.yml

service: lawos-serverless

provider:
  name: aws
  runtime: nodejs4.3
  region: eu-west-1
  stage: dev
  memorySize: 128
  timeout: 20
  iamRoleStatements:
  - Effect: "Allow"
    Action:
      - "lambda:InvokeFunction"
    Resource:
      - "*"
  - Effect: Allow
    Action:
      - sqs:DeleteMessage
      - sqs:ReceiveMessage
    Resource: arn:aws:sqs:*:*:${self:custom.sqs}

custom:
  stage: ${opt:stage, self:provider.stage}
  sns: ${self:custom.stage}-lawos-serverless-trigger
  sqs: ${self:custom.stage}-lawos-serverless-backlog

package:
  exclude:
    - node_modules/**

functions:
  task:
    handler: functions/task.handler
    name: ${self:custom.stage}-lawos-serverless-task

  worker:
    handler: functions/worker.handler
    name: ${self:custom.stage}-lawos-serverless-worker
    environment:
      sqs: ${self:custom.sqs}
      lambda: ${self:custom.stage}-lawos-serverless-task
    events:
      - schedule: rate(1 minute)
      - sns: ${self:custom.sns}

resources:
  Resources:
    BacklogQueue:
      Type: AWS::SQS::Queue
      Properties:
        QueueName: ${self:custom.sqs}
        MessageRetentionPeriod: '1209600'
        VisibilityTimeout: '60'
        RedrivePolicy:
          deadLetterTargetArn:
            Fn::GetAtt:
            - DeadLetterQueue
            - Arn
          maxReceiveCount: '10'

    DeadLetterQueue:
      Type: AWS::SQS::Queue
      Properties:
        QueueName: ${self:custom.sqs}-dead-letter-queue
        MessageRetentionPeriod: '1209600'

    QueueDepthAlarmOver100:
      Type: AWS::CloudWatch::Alarm
      Properties:
        AlarmDescription: Alarm if queue depth grows beyond 100 messages
        Namespace: AWS/SQS
        MetricName: NumberOfMessagesVisible
        Dimensions:
        - Name: QueueName
          Value: ${self:custom.sqs}
        Statistic: Sum
        Period: '60'
        EvaluationPeriods: '1'
        Threshold: '100'
        ComparisonOperator: GreaterThanOrEqualToThreshold
        AlarmActions:
        - { "Fn::Join" : ["", ["arn:aws:sns:${self:provider.region}:", { "Ref" : "AWS::AccountId" }, ":${self:custom.sns}" ] ]  }