heat_template_version: 2013-05-23
description: AutoScaling Simple
parameters:
  image:
    type: string
    description: Image used for servers
    default: ubuntu-14.04
  flavor:
    type: string
    description: flavor used by the web servers
    default: m1.small
  public_net_id:
    type: string
    description: network on which the instances
    default: private
  key_name:
    type: string
    description: Name of an existing key pair to use for the template
    default: demo


resources:
  auto_scale_group:
    type: OS::Heat::AutoScalingGroup
    properties:
      min_size: 1
      max_size: 3
      resource:
        type: OS::Nova::Server
        properties:
          name: test_server
          flavor: {get_param: flavor}
          image: {get_param: image}
          key_name: {get_param: key_name}
          metadata: {"metering.stack": {get_param: "OS::stack_id"}}
          networks:
            - network: { get_param: public_net_id }

  server_scaleup_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: auto_scale_group}
      cooldown: 60
      scaling_adjustment: 1
  server_scaledown_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: auto_scale_group}
      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: [server_scaleup_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 minute
      meter_name: cpu_util
      statistic: avg
      period: 60
      evaluation_periods: 1
      threshold: 15
      alarm_actions:
        - {get_attr: [server_scaledown_policy, alarm_url]}
      matching_metadata: {'metadata.user_metadata.stack': {get_param: "OS::stack_id"}}
      comparison_operator: lt

outputs:
  scale_up_url:
    description: >
      This URL is the webhook to scale up the group.  You can invoke
      the scale-up operation by doing an HTTP POST to this URL; no
      body nor extra headers are needed.
    value: {get_attr: [server_scaleup_policy, alarm_url]}
  scale_dn_url:
    description: >
      This URL is the webhook to scale down the group.  You can invoke
      the scale-down operation by doing an HTTP POST to this URL; no
      body nor extra headers are needed.
    value: {get_attr: [server_scaledown_policy, alarm_url]}