Cfn

gistfile1.txt

Parameters:
  InstanceCount:
      Description: Number of EC2 instances (must be between 1 and 3).
      Type: Number
      Default: 1
      MinValue: 1
      MaxValue: 3
      ConstraintDescription: Must be a number between 1 and 3.
      Description: launch EC2 instances.
  InstanceType:
      Description: Launch EC2 instances.
      Type: String
      Default: t2.micro
      AllowedValues: [ t2.micro ]

Conditions:
  Launch1: !Equals [1, 1]
  Launch2: !Not [!Equals [1, !Ref InstanceCount]]
  Launch3: !Or
  - !Not [!Equals [1, !Ref InstanceCount]]
  - !Not [!Equals [2, !Ref InstanceCount]]

Resources:
  Instance1:
      Condition: Launch1
      Type: AWS::EC2::Instance
      Properties:
        InstanceType: !Ref InstanceType
        AvailabilityZone: us-east-1a
        ImageId: ami-a4c7edb2

  Instance2:
      Condition: Launch2
      Type: AWS::EC2::Instance
      Properties:
        InstanceType: !Ref InstanceType
        AvailabilityZone: us-east-1a
        ImageId: ami-a4c7edb2

  Instance3:
      Condition: Launch3
      Type: AWS::EC2::Instance
      Properties:
        InstanceType: !Ref InstanceType
        AvailabilityZone: us-east-1a
        ImageId: ami-a4c7edb2