How to create and deploy a basic Heat template

Overview

This articles provides a basic Heat Orchestration template that creates a Heat stack.

This template will create the following and connect them up:

• A network

• A static IP

• A router

• An instance

• A floating IP

• A volume

The Heat template

Note

The template must be in yaml format and be saved with the .yaml file extension. You should also make sure that you use the correct indentation.

heat_template_version: 2016-10-14

parameters:
  flavor:
    type: string
    description: I am using the smallest flavor available because i'll be spinning up a cirros instance. You can use an environment file to override the defaults.
    default: t1.tiny
    constraints:
      - custom_constraint: nova.flavor
  image:
    type: string
    description: This uses a cirros image but you can create an environment file to change the default values.
    default: cirros
    constraints:
      - custom_constraint: glance.image
  heat_volume_size:
    type: number
    label: Volume Size (GB)
    description: External Volume Size in GB
    default: 1

resources:
  heat_volume:
    type: OS::Cinder::Volume
    properties:
      size: { get_param: heat_volume_size }
  heat_volume_attachement:
    type: OS::Cinder::VolumeAttachment
    properties:
      volume_id: { get_resource: heat_volume }
      instance_uuid: { get_resource: heat_server }
  heat_network:
    type: OS::Neutron::Net
    properties:
      admin_state_up: true
      name: heat_network
  heat_network_subnet:
    type: OS::Neutron::Subnet
    properties:
      network: { get_resource: heat_network }
      cidr: "10.1.1.0/24"
      dns_nameservers: ["8.8.8.8"]
      gateway_ip: "10.1.1.1"
      ip_version: 4
  heat_router:
    type: OS::Neutron::Router
    properties:
      external_gateway_info: { network: internet }
      name: heat_router
  heat_router_interface:
    type: OS::Neutron::RouterInterface
    properties:
      router_id: { get_resource: heat_router }
      subnet: { get_resource: heat_network_subnet }
  heat_server_port:
    type: OS::Neutron::Port
    properties:
      network: { get_resource: heat_network }
      fixed_ips:
        - subnet_id: { get_resource: heat_network_subnet }
  heat_server:
    type: OS::Nova::Server
    properties:
      name: heat_server
      flavor: { get_param: flavor }
      image: { get_param: image }
      networks:
        - port: { get_resource: heat_server_port}
  heat_server_public_ip:
    type: OS::Neutron::FloatingIP
    properties:
      floating_network: "internet"
  heat_server_ip_assoc:
    type: OS::Neutron::FloatingIPAssociation
    properties:
      floatingip_id: { get_resource: heat_server_public_ip }
      port_id: { get_resource: heat_server_port }

outputs:
  heat_server_public_ip:
    description: IP Address of the deployed heat_server instance
    value: { get_attr: [ heat_server_public_ip, floating_ip_address ]}   

Deploying the stack

Note

You must source your RC file before you run the commands below.

Create a stack by running the following command in the OpenStack CLI:

openstack stack create -t  <template name> <stack name>

For example, for the template above, run:

$ openstack stack create -t basic-stack.yaml basic-stack

This command will return the following:

+---------------------+--------------------------------------+
| Field               | Value                                |
+---------------------+--------------------------------------+
| id                  | 6be269ec-d22f-4cf0-bf04-df71cc6dcf75 |
| stack_name          | basic-stack                          |
| description         | No description                       |
| creation_time       | 2019-02-12T15:58:20Z                 |
| updated_time        | None                                 |
| stack_status        | CREATE_IN_PROGRESS                   |
| stack_status_reason | Stack CREATE started                 |
+---------------------+--------------------------------------+

Next steps

This article demonstrated how to create a basic Heat template. You should now be able to create your own templates.

If you want to create template from your existing environment, you can use a tool like Flame that converts an existing environment into a Heat template. For more information, see https://github.com/openstack/flame

The following document provides more options for configuring and creating Heat templates when using UKCloud for OpenStack:

Heat Orchestration Template (HOT) specification

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