Cloudformation Templates

Recover-EC2-CW-Alarm.yaml

# CW Alarm Template
#
# Author: Chris Sereno
# Description: This template creates or adds CW alarms to EC2 Instances and will restart and recover instances.
# There are requirements to instance recovery. See https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-recover.html
# This is a personal test template and is NOT a vetted or approved template. Use at your own risk.
#
---
AWSTemplateFormatVersion: '2010-09-09'
Description: 'CloudWatch Alarms to recover EC2 Template'

Parameters:
  InstanceId:
    Type: AWS::EC2::Instance::Id
    Description: Instance ID of your EC2
    ConstraintDescription: Instance Id of an existing EC2

  #Status check alarm
  StatusCheckFailed:
    Type: String
    Default: 'No'
    Description: 'This check verifies that your instance is reachable'
    AllowedValues:
      - 'Yes'
      - 'No'
  SCAlarmName:
    Description: Name of the Alarm
    Type: String
    Default: "EC2 Status Check Failed"
  SCAlarmDescription:
    Description: Description of the Alarm
    Type: String
    Default: "An EC2 Status Check Failed"
  SCAlarmPeriod:
    Description: The length of a period (in seconds)
    Type: Number
    Default: 60
  SCAlarmEvalPeriods:
    Description: The number of specified periods to evaluate
    Type: Number
    Default: 2
  SCAlarmThreshold:
    Description: The number of failures that have to occur
    Type: Number
    Default: 1

  #System status check alarm
  StatusCheckSystemFailed:
    Type: String
    Default: 'No'
    Description: "This check verifies that your instance's operating system is accepting traffic."
    AllowedValues:
      - 'Yes'
      - 'No'
  SCSAlarmName:
    Description: Name of the alarm
    Type: String
    Default: "EC2 System Status Check Failed"
  SCSAlarmDescription:
    Description: "Description of the Alarm"
    Type: String
    Default: "An EC2 System Status Check Failed"
  SCSAlarmPeriod:
    Description: The length of a period (in seconds)
    Type: Number
    Default: 60
  SCSAlarmEvalPeriods:
    Description: The number of specified periods to evaluate
    Type: Number
    Default: 2
  SCSAlarmThreshold:
    Description: The number of failures that have to occur
    Type: Number
    Default: 1

  #High CPU alarm
  HighCPU:
    Type: String
    Default: 'No'
    Description: "This will alarm if the CPU is above the given threshold."
    AllowedValues:
      - 'Yes'
      - 'No'
  HighCPUAlarmPeriod:
    Description: The length of a period (in seconds)
    Type: Number
    Default: 300
  HighCPUAlarmEvalPeriods:
    Description: The number of specified periods to evaluate
    Type: Number
    Default: 2
  HighCPUAlarmThreshold:
    Description: The number of failures that have to occur
    Type: Number
    Default: 90

  #High memory alarm
  HighMemory:
    Type: String
    Default: 'No'
    Description: "This will alarm if the CPU is above the given threshold."
    AllowedValues:
      - 'Yes'
      - 'No'
  HighMemAlarmPeriod:
    Description: The length of a period (in seconds)
    Type: Number
    Default: 300
  HighMemAlarmEvalPeriods:
    Description: The number of specified periods to evaluate
    Type: Number
    Default: 2
  HighMemAlarmThreshold:
    Description: The number of failures that have to occur
    Type: Number
    Default: 90

  #Alarm Actions
  AlarmAction:
    Description: This allows you take an action such as send an email or text alert. (Must be in ARN format)
    Type: String

Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
    -
      Label:
        default: "Instance ID"
      Parameters:
          - InstanceId
    -
      Label:
        default: "Status Check Failed Alarm"
      Parameters:
        - StatusCheckFailed
        - SCAlarmName
        - SCAlarmDescription
        - SCAlarmPeriod
        - SCAlarmEvalPeriods
        - SCAlarmThreshold
    -
      Label:
        default: "Status Check Failed System Alarm"
      Parameters:
        - StatusCheckSystemFailed
        - SCSAlarmName
        - SCSAlarmDescription
        - SCSAlarmPeriod
        - SCSAlarmEvalPeriods
        - SCSAlarmThreshold
    -
      Label:
        default: "High CPU Alarm"
      Parameters:
        - HighCPU
        - HighCPUAlarmPeriod
        - HighCPUAlarmEvalPeriods
        - HighCPUAlarmThreshold
    -
      Label:
        default: "High Memory Alarm"
      Parameters:
        - HighMemory
        - HighMemAlarmPeriod
        - HighMemAlarmEvalPeriods
        - HighMemAlarmThreshold
    -
      Label:
        default: "Alarm Actions"
      Parameters:
        - AlarmAction

    ParameterLabels:
      StatusCheckFailed:
        default: "Create Status Check Failed Alarm?"
      StatusCheckSystemFailed:
        default: "Create System Status Check Failed Alarm?"
      HighCPU:
        default: "Create High CPU Alarm?"

Conditions:
    # These conditions determine which OS Resource to create
    StatusAlarm: !Equals [!Ref StatusCheckFailed, 'Yes']
    SystemStatusAlarm: !Equals [!Ref StatusCheckSystemFailed, 'Yes']
    HighCPUAlarm: !Equals [!Ref HighCPU, 'Yes']
    HighMemAlarm: !Equals [!Ref HighMemory, 'Yes']

Resources:
  StatusCheckFailedAlarm:
    Type: AWS::CloudWatch::Alarm
    Condition: StatusAlarm
    Properties:
      AlarmActions:
      - {"Fn::Join" : ["", ["arn:aws:automate:", { "Ref" : "AWS::Region" }, ":ec2:reboot" ]]}
      - Ref: "AlarmAction"
      AlarmDescription: !Ref SCAlarmDescription
      AlarmName: !Join [ "-", [!Ref SCAlarmName, !Ref InstanceId] ]
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: InstanceId
          Value:
            Ref: "InstanceId"
      EvaluationPeriods: '2'
      MetricName: StatusCheckFailed
      Namespace: AWS/EC2
      Period: '60'
      Statistic: Maximum
      Threshold: '1'
      TreatMissingData: missing
      Unit: Count
      
  StatusCheckSystemFailedAlarm:
    Type: AWS::CloudWatch::Alarm
    Condition: SystemStatusAlarm
    Properties:
      AlarmActions:
      - {"Fn::Join" : ["", ["arn:aws:automate:", { "Ref" : "AWS::Region" }, ":ec2:recover" ]]}
      - Ref: "AlarmAction"
      AlarmDescription: !Ref SCSAlarmDescription
      AlarmName: !Ref SCSAlarmName
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: InstanceId
          Value:
            Ref: "InstanceId"
      EvaluationPeriods: '2'
      MetricName: StatusCheckFailed_System
      Namespace: AWS/EC2
      Period: '60'
      Statistic: Maximum
      Threshold: '1'
      TreatMissingData: missing
      Unit: Count
      
  HighCPUAlarm:
    Type: AWS::CloudWatch::Alarm
    Condition: HighCPUAlarm
    Properties:
      AlarmActions:
        - Ref: "AlarmAction"
      AlarmDescription: "High CPU alert on instance"
      AlarmName: "High CPU alert on instance"
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: InstanceId
          Value:
            Ref: "InstanceId"
      EvaluationPeriods: '2'
      MetricName: CPUUtilization
      Namespace: AWS/EC2
      Period: '300'
      Statistic: Maximum
      Threshold: '90'
      TreatMissingData: missing
      Unit: Count
  
  # For memory alarms install the Cloudwatch agent on the EC2
  # https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Install-CloudWatch-Agent.html
  HighMemAlarm:
    Type: AWS::CloudWatch::Alarm
    Condition: HighMemAlarm
    Properties:
      AlarmActions:
        - Ref: "AlarmAction"
      AlarmDescription: "High memory alert on instance"
      AlarmName: "High memory alert on instance"
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: InstanceId
          Value:
            Ref: "InstanceId"
      EvaluationPeriods: '2'
      MetricName: mem_used_percent
      Namespace: AWS/EC2
      Period: '300'
      Statistic: Maximum
      Threshold: '90'
      TreatMissingData: missing
      Unit: Count