040-budgets-budgets.yml

AWSTemplateFormatVersion: '2010-09-09'

Parameters:
  budgetName:
    Type: String
  emailAddress:
    Type: String
    Default: ''
  budgetAmount:
    Type: Number
    Default: 50

Conditions:
  hasSubscription: !Not [ !Equals [ '', !Ref emailAddress ] ]

Resources:

  NotificationTopic:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName: Budgets Notification
      TopicName: !Sub '${budgetName}-topic'

  EmailSubscription:
    Type: AWS::SNS::Subscription
    Condition: hasSubscription
    Properties:
      Endpoint: !Ref emailAddress
      Protocol: email
      TopicArn: !Ref NotificationTopic

  NotificationTopicPolicy:
    Type: AWS::SNS::TopicPolicy
    Properties:
      Topics:
        - !Ref NotificationTopic
      PolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Sid: AllowBudgetsPublish
            Effect: Allow
            Principal:
              Service: budgets.amazonaws.com
            Action: sns:Publish
            Resource: !Ref NotificationTopic

  # note that changing some attributes on Budget resources will result in an error.
  # this unfortunately is a cloudformation error described here: https://github.com/aws-cloudformation/aws-cloudformation-coverage-roadmap/issues/365
  # workaround is to delete the budget resource and then re-add it.
  Budget:
    Type: AWS::Budgets::Budget
    Properties:
      Budget:
        BudgetName: !Ref budgetName
        BudgetLimit:
          Amount: !Ref budgetAmount
          Unit: USD
        TimeUnit: MONTHLY
        BudgetType: COST
        CostTypes:
          IncludeSupport: false
      NotificationsWithSubscribers:
        - Notification:
            NotificationType: ACTUAL
            ComparisonOperator: GREATER_THAN
            Threshold: 80
            ThresholdType: PERCENTAGE
          Subscribers:
            - SubscriptionType: SNS
              Address: !Ref NotificationTopic
        - Notification:
            NotificationType: FORECASTED
            ComparisonOperator: GREATER_THAN
            Threshold: 100
            ThresholdType: PERCENTAGE
          Subscribers:
            - SubscriptionType: SNS
              Address: !Ref NotificationTopic
        - Notification:
            NotificationType: ACTUAL
            ComparisonOperator: GREATER_THAN
            Threshold: 100
            ThresholdType: PERCENTAGE
          Subscribers:
            - SubscriptionType: SNS
              Address: !Ref NotificationTopic