Assigning a Floating IP Address to Each Instance of an Autoscaling Group in OpenStack Heat

asg_of_server_with_floating.yaml

heat_template_version: 2013-05-23

description: >
  This template creates an AutoScalingGroup based on the stack
  defined in the file `server_with_floating.yaml`.

parameters:
  key_name:
    type: string
    description: Name of an existing key pair to use for the instances
    constraints:
      - custom_constraint: nova.keypair
        description: Must name a public key (pair) known to Nova
  flavor:
    type: string
    description: Flavor for the instances to be created
    default: m1.small
    constraints:
      - custom_constraint: nova.flavor
        description: Must be a flavor known to Nova
  image:
    type: string
    description: >
      Name or ID of the image to use for the instances.
      You can get the default from
    constraints:
      - custom_constraint: glance.image
        description: Must identify an image known to Glance
  network:
    type: string
    description: The network for the VM
    constraints:
      - {custom_constraint: neutron.network}
  public_net:
    type: string
    description: >
      ID of public network for which floating IP addresses will be allocated
    constraints:
      - {custom_constraint: neutron.network}

resources:
  asg:
    type: OS::Heat::AutoScalingGroup
    properties:
      resource:
        type: server_with_floating.yaml
        properties:
            key_name: { get_param: key_name }
            image: { get_param: image }
            flavor: { get_param: flavor }
            network: { get_param: network }
            public_net: { get_param: public_net}
      min_size: 1
      desired_capacity: 3
      max_size: 20

  scale_up_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: asg}
      cooldown: 1
      scaling_adjustment: 3

  scale_dn_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: asg}
      cooldown: 1
      scaling_adjustment: '-1'

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: [scale_up_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: [scale_dn_policy, alarm_url]}

create-stack.sh

#!/bin/bash

openstack stack create my-test-stack --template asg_of_server_with_floating.yaml -e environment.yaml

environment.yaml

parameters:
  key_name: admin
  flavor: m1.small
  image: Ubuntu 14.04 (trusty)
  network: 1234567-...................
  public_net: 1234567-...................

server_with_floating.yaml

heat_template_version: 2013-05-23

description: >
  Creates a server and assigns a floating IP.

parameters:
  key_name:
    type: string
    description: Name of an existing key pair to use for the instances
    constraints:
      - custom_constraint: nova.keypair
        description: Must name a public key (pair) known to Nova
  flavor:
    type: string
    description: Flavor for the instances to be created
    default: m1.small
    constraints:
      - custom_constraint: nova.flavor
        description: Must be a flavor known to Nova
  image:
    type: string
    description: >
      Name or ID of the image to use for the instances.
      You can get the default from
    constraints:
      - custom_constraint: glance.image
        description: Must identify an image known to Glance
  network:
    type: string
    description: The network for the VM
    constraints:
      - {custom_constraint: neutron.network}
  public_net:
    type: string
    description: >
      ID of public network for which floating IP addresses will be allocated
    constraints:
      - {custom_constraint: neutron.network}


resources:
  server1:
    type: OS::Nova::Server
    properties:
      name: Server with Floating IP
      image: { get_param: image }
      flavor: { get_param: flavor }
      key_name: { get_param: key_name }
      networks:
        - port: { get_resource: server1_port }

  server1_port:
    type: OS::Neutron::Port
    properties:
      network_id: { get_param: network }
      security_groups: [{ get_resource: server_security_group }]

  server1_floating_ip:
    type: OS::Neutron::FloatingIP
    properties:
      floating_network_id: { get_param: public_net }
      port_id: { get_resource: server1_port }

  server_security_group:
    type: OS::Neutron::SecurityGroup
    properties:
      description: Add security group rules for server
      name: security-group
      rules:
        - remote_ip_prefix: 0.0.0.0/0
          protocol: tcp
          port_range_min: 22
          port_range_max: 22
        - remote_ip_prefix: 0.0.0.0/0
          protocol: icmp

outputs:
  server1_private_ip:
    description: IP address of server1 in private network
    value: { get_attr: [ server1, first_address ] }
  server1_public_ip:
    description: Floating IP address of server1 in public network
    value: { get_attr: [ server1_floating_ip, floating_ip_address ] }