aws-ec2-scheduler-central.yml

AWSTemplateFormatVersion: 2010-09-09
Description: 'AWS EC2 Scheduler: Central'

Parameters:
  IntervalMinutes:
    Type: Number
    Description: Enter interval time (in minutes)
    MinValue: 1
    MaxValue: 1440
    Default: 60
    ConstraintDescription: must be between 1 and 1,440.

  ForceSchedule:
    Type: String
    Description: Select whether to enforce the tagging
    AllowedValues:
      - "true"
      - "false"
    Default: false
    ConstraintDescription: must be a valid selection.

  ForceStop:
    Type: String
    Description: Select whether to enforce the tagging
    AllowedValues:
      - "true"
      - "false"
    Default: false
    ConstraintDescription: must be a valid selection.

  SmartStop:
    Type: String
    Description: Select whether to enforce the tagging
    AllowedValues:
      - "true"
      - "false"
    Default: false
    ConstraintDescription: must be a valid selection.

  S3Bucket:
    Type: String
    Description: S3 bucket (in the same AWS Region) containing the Lambda code file
    ConstraintDescription: must be non-empty.

  S3Key:
    Type: String
    Description: S3 key of the Lambda code file
    ConstraintDescription: must be non-empty.

Conditions:
  Singular: !Equals [!Ref IntervalMinutes, 1]
      
Resources:
  EC2Scheduler:
    Type: AWS::Events::Rule
    Properties:
      Name: !Ref 'AWS::StackName'
      Description: !Join ['', [Rule that triggers every, ' ', !Ref IntervalMinutes, ' ', !If [Singular, minute, minutes]]]
      ScheduleExpression: !Join ['', [rate(, !Ref IntervalMinutes, ' ', !If [Singular, minute, minutes], )]]
      Targets:
        - Id: start-stop-ec2-instances
          Arn: !GetAtt StartStopEC2Instances.Arn
          Input: !Join ['', ['{ "IntervalMinutes" : ', !Ref IntervalMinutes, ', "ForceSchedule" : ', !Ref ForceSchedule, 
                        ', "ForceStop" : ', !Ref ForceStop, ', "SmartStop" : ', !Ref SmartStop, ' }']]

  StartStopEC2Instances:
    Type: AWS::Lambda::Function
    Properties:
      Runtime: python3.8
      Role: !GetAtt LambdaEC2StartStopInstances.Arn
      FunctionName: start-stop-ec2-instances
      Handler: lambda_function.lambda_handler
      Timeout: 900
      Code:
        S3Bucket: !Ref S3Bucket
        S3Key: !Ref S3Key  

  StartStopEC2InstancesPermission:
    Type: AWS::Lambda::Permission
    Properties:
      FunctionName: !GetAtt StartStopEC2Instances.Arn
      Action: 'lambda:InvokeFunction'
      Principal: events.amazonaws.com
      SourceArn: !GetAtt EC2Scheduler.Arn
  
  LambdaEC2StartStopInstances:
    Type: AWS::IAM::Role
    Properties:
      RoleName: lambda-ec2-start-stop-instances
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: sts:AssumeRole
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

  AutoscalingDescribeUpdateGroup:
    Type: AWS::IAM::Policy
    Properties:
      PolicyName: autoscaling-describe-update-group
      Roles:
        - !Ref LambdaEC2StartStopInstances
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - autoscaling:DescribeAutoScalingGroups
              - autoscaling:UpdateAutoScalingGroup
            Resource: '*'

  EC2StartStopInstances:
    Type: AWS::IAM::Policy
    Properties:
      PolicyName: ec2-start-stop-instances
      Roles:
        - !Ref LambdaEC2StartStopInstances
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action: 
              - ec2:StartInstances
              - ec2:StopInstances
              - ec2:DescribeInstances
              - ec2:DescribeTags
              - ec2:DescribeRegions
            Resource: '*'