instance_group.yaml

# http://docs.openstack.org/developer/heat/template_guide/hot_spec.html#heat-template-version
heat_template_version: 2014-10-16


description: >
  A template that will create 1 -3 instances of a server, dependent on user choice.


parameters:

  key_name:
    description: The name of an existing Nectar KeyPair (enables SSH access to the instances)
    type: string

  instance_type:
    description: The NeCTAR flavor the webserver is to run on
    type: string
    default: m1.small
    constraints:
      - allowed_values: [ m1.small, m1.medium, m1.large, m1.xlarge ]
        description: Value must be one of m1.small, m1.medium, m1.large or m1.xlarge.

  image_id:
    type: string
    description: ID of the image to use for the instance to be created
    default: fc48b5bb-e67d-4e39-b9ba-b6725c8b0c88

  # We will limit the maximum number of instances to 2. Just because.
  instance_count:
    type: number
    default: 2
    constraints:
      - range: { min: 1, max: 3 }
        description: "The number of instances to create"


resources:

  server_config:
    # http://docs.openstack.org/hot-reference/content/AWS__AutoScaling__LaunchConfiguration.html
    type: "AWS::AutoScaling::LaunchConfiguration"
    properties:
      ImageId: { get_param: image_id }
      InstanceType: { get_param: instance_type }
      KeyName: { get_param: key_name }
      UserData: >
        #!/bin/bash -v

  server_group:
    # http://docs.openstack.org/hot-reference/content/OS__Heat__InstanceGroup.html
    type: "OS::Heat::InstanceGroup"
    properties:
      LaunchConfigurationName: { get_resource: server_config}
      Size: { get_param: instance_count }
      AvailabilityZones: [ although, required, this, is, ignored ]
      # We will add some metadata to each instance created.
      Tags:
        -
          Key: "First"
          Value: "Verity"