webapp-cloudwatch.yaml

# Note, This template deploys CloudWatch Setup
#
---
AWSTemplateFormatVersion: "2010-09-09"
Description: >
    This template deploys CloudWatch Setup,
    Scale-up if CPU > 80% for 5 minutes
    Scale-down if CPU < 25% for 5 minutes

Parameters: 

  PMWebScalingGroup:
    Description: "A reference to the WebServer AutoScalingGroup"
    Type: "String"

  PMWebServerScaleUpPolicy:
    Description: "A reference to the WebServer ScaleUpPolicy"
    Type: "String"

  PMWebServerScaleDownPolicy:
    Description: "A reference to the WebServer ScaleDownPolicy"
    Type: "String"

  PMAppScalingGroup:
    Description: "A reference to the AppServer AutoScalingGroup"
    Type: "String"

  PMAPPServerScaleUpPolicy:
    Description: "A reference to the AppServer ScaleUpPolicy"
    Type: "String"

  PMAPPServerScaleDownPolicy:
    Description: "A reference to the AppServer ScaleDownPolicy"
    Type: "String"


Resources:

  #  Web Server Alarm High Load
  WebCPUAlarmHigh:
    Type: "AWS::CloudWatch::Alarm"
    Properties:
      AlarmDescription: "Scale-up if CPU > 80% for 5 minutes"
      MetricName: "CPUUtilization"
      Namespace: "AWS/EC2"
      Statistic: "Average"
      Period: '300'
      EvaluationPeriods: '1'
      Threshold: '80'
      AlarmActions:
      - Ref: "PMWebServerScaleUpPolicy"
      Dimensions:
      - Name: "AutoScalingGroupName"
        Value:
          Ref: "PMWebScalingGroup"
      ComparisonOperator: "GreaterThanThreshold"

  # Web Server Alarm Low Load
  WebCPUAlarmLow:
    Type: "AWS::CloudWatch::Alarm"
    Properties:
      AlarmDescription: "Scale-down if CPU < 25% for 5 minutes"
      MetricName: "CPUUtilization"
      Namespace: "AWS/EC2"
      Statistic: "Average"
      Period: '300'
      EvaluationPeriods: '1'
      Threshold: '25'
      AlarmActions:
      - Ref: "PMWebServerScaleDownPolicy"
      Dimensions:
      - Name: "AutoScalingGroupName"
        Value:
          Ref: "PMWebScalingGroup"
      ComparisonOperator: "GreaterThanThreshold"

  #  App Server Alarm High Load
  AppCPUAlarmHigh:
    Type: "AWS::CloudWatch::Alarm"
    Properties:
      AlarmDescription: "Scale-up if CPU > 80% for 5 minutes"
      MetricName: "CPUUtilization"
      Namespace: "AWS/EC2"
      Statistic: "Average"
      Period: '300'
      EvaluationPeriods: '1'
      Threshold: '80'
      AlarmActions:
      - Ref: "PMAPPServerScaleUpPolicy"
      Dimensions:
      - Name: "AutoScalingGroupName"
        Value:
          Ref: "PMAppScalingGroup"
      ComparisonOperator: "GreaterThanThreshold"

  # App Server Alarm Low Load
  AppCPUAlarmLow:
    Type: "AWS::CloudWatch::Alarm"
    Properties:
      AlarmDescription: "Scale-down if CPU < 25% for 5 minutes"
      MetricName: "CPUUtilization"
      Namespace: "AWS/EC2"
      Statistic: "Average"
      Period: '300'
      EvaluationPeriods: '1'
      Threshold: '25'
      AlarmActions:
      - Ref: "PMAPPServerScaleDownPolicy"
      Dimensions:
      - Name: "AutoScalingGroupName"
        Value:
          Ref: "PMAppScalingGroup"
      ComparisonOperator: "GreaterThanThreshold"


Outputs:

  WebTrafficAlarmHigh:
    Description: "CloudWatch Reference Web AlarmHigh"
    Value: !Ref "WebCPUAlarmHigh"

  WebTrafficAlarmLow: 
    Description: "CloudWatch Reference Web AlarmLow"
    Value: !Ref "WebCPUAlarmLow"

  AppTrafficAlarmHigh: 
    Description: "CloudWatch Reference App AlarmHigh"
    Value: !Ref "AppCPUAlarmHigh"

  AppTrafficAlarmLow: 
    Description: "CloudWatch Reference App AlarmLow"
    Value: !Ref "AppCPUAlarmLow"