heat_template_version: 2013-05-23

parameters:
  KeyName:
    type: string
  InstanceType:
    type: string
  ImageId:
    type: string
  SecurityGroup:
    type: string
  Subnet:
    type: string

resources:
  my_asg:
    type: OS::Heat::AutoScalingGroup
    properties:
      resource:
        type: OS::Nova::Server
        properties:
          metadata: {"metering.stack": {get_param: "OS::stack_id"}}
          key_name: { get_param: KeyName }
          image: { get_param: ImageId }
          flavor: { get_param: InstanceType }
          security_groups:
          - get_param: SecurityGroup
          networks:
          - network: {get_param: Subnet}
      min_size: 1
      max_size: 2

  scale_up_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: my_asg}
      cooldown: 60
      scaling_adjustment: 1

  scale_down_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: my_asg}
      cooldown: 60
      scaling_adjustment: '-1'

  cpu_alarm_high:
    type: OS::Ceilometer::Alarm
    properties:
      description: Scale-up if the average CPU > 50% for 1 minute
      meter_name: cpu_util
      statistic: avg
      period: 60
      evaluation_periods: 1
      threshold: 50
      alarm_actions:
        - {get_attr: [scale_up_policy, alarm_url]}
      matching_metadata: {'metadata.user_metadata.stack': {get_param: "OS::stack_id"}}
      comparison_operator: gt

  cpu_alarm_low:
    type: OS::Ceilometer::Alarm
    properties:
      description: Scale-down if the average CPU < 15% for 1 minutes
      meter_name: cpu_util
      statistic: avg
      period: 60
      evaluation_periods: 1
      threshold: 15
      alarm_actions:
        - {get_attr: [scale_down_policy, alarm_url]}
      matching_metadata: {'metadata.user_metadata.stack': {get_param: "OS::stack_id"}}
      comparison_operator: lt