marbot-cloudfront.yml

---
# Copyright widdix GmbH
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
AWSTemplateFormatVersion: '2010-09-09'
Description: 'marbot.io: CloudFront monitoring (https://github.com/marbot-io/monitoring-jump-start)'
Metadata:
  'AWS::CloudFormation::Interface':
    ParameterGroups:
    - Label:
        default: 'marbot endpoint'
      Parameters:
      - EndpointId
      - Stage
    - Label:
        default: 'CloudFront'
      Parameters:
      - CloudFrontDistributionId
    - Label:
        default: 'Thresholds'
      Parameters:
      - 5xxErrorRateThreshold
      - LambdaExecutionErrorThreshold
      - LambdaValidationErrorThreshold
      - CacheHitRateThreshold
      - OriginLatenyThreshold
Parameters:
  EndpointId:
    Description: 'Your marbot endpoint ID (to get this value: select a channel where marbot belongs to and send a message like this: "@marbot show me my endpoint id").'
    Type: String
  Stage:
    Description: 'marbot stage (never change this!).'
    Type: String
    Default: v1
    AllowedValues: [v1, dev]
  CloudFrontDistributionId:
    Description: 'The CloudFront distribution ID that you want to monitor.'
    Type: String
  5xxErrorRateThreshold:
    Description: 'The 5xx error rate threshold (set to -1 to disable).'
    Type: Number
    Default: 0.01
    MinValue: -1
  LambdaExecutionErrorThreshold:
    Description: 'The Lambda@Edge execution error count threshold (set to -1 to disable).'
    Type: Number
    Default: -1
    MinValue: -1
  LambdaValidationErrorThreshold:
    Description: 'The Lambda@Edge validation error count threshold (set to -1 to disable).'
    Type: Number
    Default: -1
    MinValue: -1
  CacheHitRateThreshold:
    Description: 'The cache hit rate threshold (set to -1 to disable; requires detailed monitoring).'
    Type: Number
    Default: -1
    MinValue: -1
  OriginLatenyThreshold:
    Description: 'The origin latency threshold in ms using the 99.5 percentile (set to -1 to disable; requires detailed monitoring).'
    Type: Number
    Default: -1
    MinValue: -1
Conditions:
  Has5xxErrorRateThreshold: !Not [!Equals [!Ref 5xxErrorRateThreshold, '-1']]
  HasLambdaExecutionErrorThreshold: !Not [!Equals [!Ref LambdaExecutionErrorThreshold, '-1']]
  HasLambdaValidationErrorThreshold: !Not [!Equals [!Ref LambdaValidationErrorThreshold, '-1']]
  HasCacheHitRateThreshold: !Not [!Equals [!Ref CacheHitRateThreshold, '-1']]
  HasOriginLatenyThreshold: !Not [!Equals [!Ref OriginLatenyThreshold, '-1']]
Resources:
  ##########################################################################
  #                                                                        #
  #                                 TOPIC                                  #
  #                                                                        #
  ##########################################################################
  Topic:
    Type: 'AWS::SNS::Topic'
    Properties: {}
  TopicPolicy:
    Type: 'AWS::SNS::TopicPolicy'
    Properties:
      PolicyDocument:
        Id: Id1
        Version: '2012-10-17'
        Statement:
        - Sid: Sid1
          Effect: Allow
          Principal:
            Service: 'events.amazonaws.com' # Allow EventBridge
          Action: 'sns:Publish'
          Resource: !Ref Topic
        - Sid: Sid2
          Effect: Allow
          Principal:
            AWS: '*' # Allow CloudWatch Alarms
          Action: 'sns:Publish'
          Resource: !Ref Topic
          Condition:
            StringEquals:
              'AWS:SourceOwner': !Ref 'AWS::AccountId'
      Topics:
      - !Ref Topic
  TopicEndpointSubscription:
    DependsOn: TopicPolicy
    Type: 'AWS::SNS::Subscription'
    Properties:
      DeliveryPolicy:
        healthyRetryPolicy:
          minDelayTarget: 1
          maxDelayTarget: 60
          numRetries: 100
          numNoDelayRetries: 0
          backoffFunction: exponential
        throttlePolicy:
          maxReceivesPerSecond: 1
      Endpoint: !Sub 'https://api.marbot.io/${Stage}/endpoint/${EndpointId}'
      Protocol: https
      TopicArn: !Ref Topic
  MonitoringJumpStartEvent:
    DependsOn: TopicEndpointSubscription
    Type: 'AWS::Events::Rule'
    Properties:
      Description: 'Monitoring Jump Start connection. (created by marbot)'
      ScheduleExpression: 'rate(30 days)'
      State: ENABLED
      Targets:
      - Arn: !Ref Topic
        Id: marbot
        Input: !Sub |
          {
            "Type": "monitoring-jump-start-connection",
            "StackTemplate": "marbot-cloudfront",
            "StackVersion": "1.1.1",
            "Partition": "${AWS::Partition}",
            "AccountId": "${AWS::AccountId}",
            "Region": "${AWS::Region}",
            "StackId": "${AWS::StackId}",
            "StackName": "${AWS::StackName}"
          }
  ##########################################################################
  #                                                                        #
  #                                 ALARMS                                 #
  #                                                                        #
  ##########################################################################
  5xxErrorRateTooHighAlarm:
    Condition: Has5xxErrorRateThreshold
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmActions:
      - !Ref Topic
      AlarmDescription: 'CloudFront distribution returns too many 5xx errors.'
      ComparisonOperator: GreaterThanThreshold
      Dimensions:
      - Name: Region
        Value: Global
      - Name: DistributionId
        Value: !Ref CloudFrontDistributionId
      EvaluationPeriods: 1
      MetricName: 5xxErrorRate
      Namespace: 'AWS/CloudFront'
      OKActions:
      - !Ref Topic
      Period: 60
      Statistic: Average
      Threshold: !Ref 5xxErrorRateThreshold
      TreatMissingData: notBreaching
  LambdaExecutionErrorTooHighAlarm:
    Condition: HasLambdaExecutionErrorThreshold
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmActions:
      - !Ref Topic
      AlarmDescription: 'CloudFront distribution failed to execute Lambde@Edge.'
      ComparisonOperator: GreaterThanThreshold
      Dimensions:
      - Name: Region
        Value: Global
      - Name: DistributionId
        Value: !Ref CloudFrontDistributionId
      EvaluationPeriods: 1
      MetricName: LambdaExecutionError
      Namespace: 'AWS/CloudFront'
      OKActions:
      - !Ref Topic
      Period: 60
      Statistic: Sum
      Threshold: !Ref LambdaValidationErrorThreshold
      TreatMissingData: notBreaching
  LambdaValidationErrorTooHighAlarm:
    Condition: HasLambdaValidationErrorThreshold
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmActions:
      - !Ref Topic
      AlarmDescription: 'CloudFront distribution received invalid response from Lambde@Edge.'
      ComparisonOperator: GreaterThanThreshold
      Dimensions:
      - Name: Region
        Value: Global
      - Name: DistributionId
        Value: !Ref CloudFrontDistributionId
      EvaluationPeriods: 1
      MetricName: LambdaValidationError
      Namespace: 'AWS/CloudFront'
      OKActions:
      - !Ref Topic
      Period: 60
      Statistic: Sum
      Threshold: !Ref LambdaValidationErrorThreshold
      TreatMissingData: notBreaching
  CacheHitRateAlarm:
    Condition: HasCacheHitRateThreshold
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmActions:
      - !Ref Topic
      AlarmDescription: 'Cache hit rate on CloudFront distribution too low.'
      ComparisonOperator: LessThanThreshold
      Dimensions:
      - Name: Region
        Value: Global
      - Name: DistributionId
        Value: !Ref CloudFrontDistributionId
      EvaluationPeriods: 1
      MetricName: CacheHitRate
      Namespace: 'AWS/CloudFront'
      OKActions:
      - !Ref Topic
      Period: 900
      Statistic: Average
      Threshold: !Ref CacheHitRateThreshold
      TreatMissingData: notBreaching
  OriginLatencyAlarm:
    Condition: HasOriginLatenyThreshold
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmActions:
      - !Ref Topic
      AlarmDescription: 'Low latency from CloudFront to origin.'
      ComparisonOperator: GreaterThanThreshold
      Dimensions:
      - Name: Region
        Value: Global
      - Name: DistributionId
        Value: !Ref CloudFrontDistributionId
      EvaluationPeriods: 1
      MetricName: OriginLatency
      Namespace: 'AWS/CloudFront'
      OKActions:
      - !Ref Topic
      Period: 900
      ExtendedStatistic: 'p99.5'
      Threshold: !Ref OriginLatenyThreshold
      TreatMissingData: notBreaching
Outputs:
  StackName:
    Description: 'Stack name.'
    Value: !Sub '${AWS::StackName}'
  StackTemplate:
    Description: 'Stack template.'
    Value: 'marbot-cloudfront'
  StackVersion:
    Description: 'Stack version.'
    Value: '1.1.1'