Openstack orchestration

Colection of Openstack resources that work together as three-tier application is called a stack. Stack uses openstack resources like instances, networks, volumes and objects, and other elements. The application runs on a stack.

Stack can be set-up via CLI or Horizon GUI which will send API request to various Openstack services (Keystone, Nova, Neutron, Cinder, Swift, Glance …).

Heat is the Openstack orchestration service that sends these API requests automatically. Stack description is taken by heat and interpreted to API requests. Heat accepts AWS Cloudformation templates written in JSON, but heat has it’s own native format called Heat Orchestration Template (HOT) based on YAML.

Create simple stack with heat orchestration template:
heat_template_version: newton

resources:
   myserver:
      type: OS::Nova::Server
      properties:
         config_drive: true
         key_name: 'erol-keypair'
         image: 'cirros-image'
         flavor: 1
         networks:
           - network: 'private_network'
Validate
openstack orchestration template validate --template simple-stack.yaml
If everything is ok, there will be no errors shown:
Description: No description
Parameters: {}
Create stack:
openstack stack create -t simple-stack.yaml simple-stack
+---------------------+--------------------------------------+
| Field               | Value                                |
+---------------------+--------------------------------------+
| id                  | c0e028fd-6d10-4bd5-b3a0-5b0509ded846 |
| stack_name          | simple-stack                         |
| description         | No description                       |
| creation_time       | 2020-04-30T13:06:57Z                 |
| updated_time        | None                                 |
| stack_status        | CREATE_IN_PROGRESS                   |
| stack_status_reason | Stack CREATE started                 |
+---------------------+--------------------------------------+
List stacks to check if it has finished creating:
openstack stack list
+--------------------------------------+--------------+-----------------+----------------------+--------------+
| ID                                   | Stack Name   | Stack Status    | Creation Time        | Updated Time |
+--------------------------------------+--------------+-----------------+----------------------+--------------+
| c0e028fd-6d10-4bd5-b3a0-5b0509ded846 | simple-stack | CREATE_COMPLETE | 2020-04-30T13:06:57Z | None         |
+--------------------------------------+--------------+-----------------+----------------------+--------------+
List all resources belonging to the stack:
openstack stack resource list simple-stack
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| resource_name | physical_resource_id                 | resource_type    | resource_status | updated_time         |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| myserver      | d6d86e6d-d904-4f90-90af-8efebf45aea2 | OS::Nova::Server | CREATE_COMPLETE | 2020-04-30T13:06:57Z |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
Change server name in simple-stack.yaml:
myserver;
to:
server
Update the stack:
openstack stack update -t simple-stack.yaml.1 simple-stack*
* Changing the resource name of the server will delete old instance and create new instance with new resource_name.
+---------------------+--------------------------------------+
| Field               | Value                                |
+---------------------+--------------------------------------+
| id                  | c0e028fd-6d10-4bd5-b3a0-5b0509ded846 |
| stack_name          | simple-stack                         |
| description         | No description                       |
| creation_time       | 2020-04-30T13:06:57Z                 |
| updated_time        | 2020-04-30T13:14:59Z                 |
| stack_status        | UPDATE_IN_PROGRESS                   |
| stack_status_reason | Stack UPDATE started                 |
+---------------------+--------------------------------------+
Check if stack was updated successfuly:
openstack stack list
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
| ID                                   | Stack Name   | Stack Status    | Creation Time        | Updated Time         |
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
| c0e028fd-6d10-4bd5-b3a0-5b0509ded846 | simple-stack | UPDATE_COMPLETE | 2020-04-30T13:06:57Z | 2020-04-30T13:14:59Z |
+--------------------------------------+--------------+-----------------+----------------------+----------------------+

Check if resource list was updated:
openstack stack resource list simple-stack
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| resource_name | physical_resource_id                 | resource_type    | resource_status | updated_time         |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| server        | 62d20902-ee6c-40a0-bdc6-e38ed81fdf7c | OS::Nova::Server | CREATE_COMPLETE | 2020-04-30T13:14:59Z |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
Change network in simple-stack.yaml.1:
network: 'private_network'
to:
network: 'external_network'
openstack stack update -t simple-stack.yaml.2 simple-stack
+---------------------+--------------------------------------+
| Field               | Value                                |
+---------------------+--------------------------------------+
| id                  | c0e028fd-6d10-4bd5-b3a0-5b0509ded846 |
| stack_name          | simple-stack                         |
| description         | No description                       |
| creation_time       | 2020-04-30T13:06:57Z                 |
| updated_time        | 2020-04-30T13:39:28Z                 |
| stack_status        | UPDATE_IN_PROGRESS                   |
| stack_status_reason | Stack UPDATE started                 |
+---------------------+--------------------------------------+
openstack stack resource list simple-stack
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| resource_name | physical_resource_id                 | resource_type    | resource_status | updated_time         |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| server        | 62d20902-ee6c-40a0-bdc6-e38ed81fdf7c | OS::Nova::Server | UPDATE_COMPLETE | 2020-04-30T13:39:31Z |
+---------------+--------------------------------------+------------------+-----------------+----------------------+

Retrieve all parameter functions supported by Openstack version:

openstack orchestration template version list
+--------------------------------------+------+
| version                              | type |
+--------------------------------------+------+
| AWSTemplateFormatVersion.2010-09-09  | cfn  |
| HeatTemplateFormatVersion.2012-12-12 | cfn  |
| heat_template_version.2013-05-23     | hot  |
| heat_template_version.2014-10-16     | hot  |
| heat_template_version.2015-04-30     | hot  |
| heat_template_version.2015-10-15     | hot  |
| heat_template_version.2016-04-08     | hot  |
| heat_template_version.2016-10-14     | hot  |
+--------------------------------------+------+
openstack orchestration template function list heat_template_version.2016-10-14
+-----------------+-------------------------------------------------------------------------+
| functions       | description                                                             |
+-----------------+-------------------------------------------------------------------------+
| list_join       | A function for joining one or more lists of strings.                    |
| if              | A function to return corresponding value based on condition evaluation. |
| yaql            | A function for executing a yaql expression.                             |
| digest          | A function for performing digest operations.                            |
| get_attr        | A function for resolving resource attributes.                           |
| repeat          | A function for iterating over a list of items.                          |
| resource_facade | A function for retrieving data in a parent provider template.           |
| map_replace     | A function for performing substitutions on maps.                        |
| str_replace     | A function for performing string substitutions.                         |
| get_resource    | A function for resolving resource references.                           |
| map_merge       | A function for merging maps.                                            |
| str_split       | A function for splitting delimited strings into a list.                 |
| get_param       | A function for resolving parameter references.                          |
| get_file        | A function for including a file inline.                                 |
+-----------------+-------------------------------------------------------------------------+

Parameters can be provided via command line with
--parameter imgname=cirros-image keyname=erol-keypair
Or combine several parameters under one option:
--parameter "imgname=cirros-image; keyname=erol-keypair"

If you have a lot of parameters it is probably better to put them in a file again in YAML format, with single parameters key and parameter key value pairs under that key. For example create myparameters.yaml file with following contents:

parameters:
   keyname: erol-keypair
   imgname: cirros-image

You can now use –enviroment option to include the parameter keypairs from your file to the heat orchestration template.

Contents of parameters-stack.yaml:

heat_template_version: newton

parameters:
  keyname:
    type: string
    default: erol-keypair
    description: .....
  imgname:
    type: string

resources:
   server:
      type: OS::Nova::Server
      properties:
         config_drive: true
         key_name: { get_param: keyname }
         image: { get_param: imgname }
         flavor: 1
         networks:
           - network: 'private_network'

You can create your new stack with new template and parameters file:

openstack stack create myfirststack --template parameters-stack.yaml -e myparameters.yaml
+---------------------+--------------------------------------+
| Field               | Value                                |
+---------------------+--------------------------------------+
| id                  | ccc6b0a3-f690-479b-87fd-d36b1077f53c |
| stack_name          | myfirststack                         |
| description         | No description                       |
| creation_time       | 2020-04-30T14:08:58Z                 |
| updated_time        | None                                 |
| stack_status        | CREATE_IN_PROGRESS                   |
| stack_status_reason | Stack CREATE started                 |
+---------------------+--------------------------------------+
[root@packstack ~(keystone_admin)]# openstack stack list
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
| ID                                   | Stack Name   | Stack Status    | Creation Time        | Updated Time         |
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
| ccc6b0a3-f690-479b-87fd-d36b1077f53c | myfirststack | CREATE_COMPLETE | 2020-04-30T14:08:58Z | None                 |
| c0e028fd-6d10-4bd5-b3a0-5b0509ded846 | simple-stack | UPDATE_COMPLETE | 2020-04-30T13:06:57Z | 2020-04-30T13:39:28Z |
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
openstack stack resource list myfirststack
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| resource_name | physical_resource_id                 | resource_type    | resource_status | updated_time         |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| server        | e7378fa5-ed43-48eb-b00e-17952d4aad97 | OS::Nova::Server | CREATE_COMPLETE | 2020-04-30T14:08:59Z |
+---------------+--------------------------------------+------------------+-----------------+----------------------+

Create a modified version of your HOT file called linking-stack.yaml:

heat_template_version: newton

parameters:
  keyname:
    type: string
    default: erol-keypair
    description: .....
  imgname:
    type: string

resources:
   fip:
     type: OS::Nova::FloatingIP
     properties:
       pool: external_network
   fip_assoc:
     type: OS::Nova::FloatingIPAssociation
     properties:
       server_id: { get_resource: server }
       floating_ip: { get_resource: fip }

   server:
      type: OS::Nova::Server
      properties:
         config_drive: true
         key_name: { get_param: keyname }
         image: { get_param: imgname }
         flavor: 1
         networks:
           - network: 'private_network'
outputs:
   fip_address:
      description: Floating IP address value
      value:
         get_attr: [ fip, ip ]

Create a modified version of your HOT file called linking-stack.yaml:

openstack stack create linkstack --template linking-stack.yaml -e myparameters.yaml
+---------------------+--------------------------------------+
| Field               | Value                                |
+---------------------+--------------------------------------+
| id                  | eb146b58-a00e-4d5c-897f-243d6c55c4ea |
| stack_name          | linkstack                            |
| description         | No description                       |
| creation_time       | 2020-04-30T14:22:51Z                 |
| updated_time        | None                                 |
| stack_status        | CREATE_IN_PROGRESS                   |
| stack_status_reason | Stack CREATE started                 |
+---------------------+--------------------------------------+
openstack stack list
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
| ID                                   | Stack Name   | Stack Status    | Creation Time        | Updated Time         |
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
| eb146b58-a00e-4d5c-897f-243d6c55c4ea | linkstack    | CREATE_COMPLETE | 2020-04-30T14:22:51Z | None                 |
| ccc6b0a3-f690-479b-87fd-d36b1077f53c | myfirststack | CREATE_COMPLETE | 2020-04-30T14:08:58Z | None                 |
| c0e028fd-6d10-4bd5-b3a0-5b0509ded846 | simple-stack | UPDATE_COMPLETE | 2020-04-30T13:06:57Z | 2020-04-30T13:39:28Z |
+--------------------------------------+--------------+-----------------+----------------------+----------------------+
openstack stack event list linkstack
2020-04-30 14:22:52Z [linkstack]: CREATE_IN_PROGRESS  Stack CREATE started
2020-04-30 14:22:54Z [linkstack.fip]: CREATE_IN_PROGRESS  state changed
2020-04-30 14:22:58Z [linkstack.link-server]: CREATE_IN_PROGRESS  state changed
2020-04-30 14:22:59Z [linkstack.fip]: CREATE_COMPLETE  state changed
2020-04-30 14:23:19Z [linkstack.link-server]: CREATE_COMPLETE  state changed
2020-04-30 14:23:24Z [linkstack.fip_assoc]: CREATE_IN_PROGRESS  state changed
2020-04-30 14:23:36Z [linkstack.fip_assoc]: CREATE_COMPLETE  state changed
2020-04-30 14:23:37Z [linkstack]: CREATE_COMPLETE  Stack CREATE completed successfully
openstack stack show linkstack
+-----------------------+----------------------------------------------------------------------------------------------------------------------------+
| Field                 | Value                                                                                                                      |
+-----------------------+----------------------------------------------------------------------------------------------------------------------------+
| id                    | eb146b58-a00e-4d5c-897f-243d6c55c4ea                                                                                       |
| stack_name            | linkstack                                                                                                                  |
| description           | No description                                                                                                             |
| creation_time         | 2020-04-30T14:22:51Z                                                                                                       |
| updated_time          | None                                                                                                                       |
| stack_status          | CREATE_COMPLETE                                                                                                            |
| stack_status_reason   | Stack CREATE completed successfully                                                                                        |
| parameters            | OS::project_id: 7f64b208cc8b4a5988317789af7f827f                                                                           |
|                       | OS::stack_id: eb146b58-a00e-4d5c-897f-243d6c55c4ea                                                                         |
|                       | OS::stack_name: linkstack                                                                                                  |
|                       | imgname: cirros-image                                                                                                      |
|                       | keyname: erol-keypair                                                                                                      |
|                       |                                                                                                                            |
| outputs               | - description: Floating IP address value                                                                                   |
|                       |   output_key: fip_address                                                                                                  |
|                       |   output_value: 172.30.152.22                                                                                              |
|                       |                                                                                                                            |
| links                 | - href: http://172.30.152.4:8004/v1/7f64b208cc8b4a5988317789af7f827f/stacks/linkstack/eb146b58-a00e-4d5c-897f-243d6c55c4ea |
|                       |   rel: self                                                                                                                |
|                       |                                                                                                                            |
| parent                | None                                                                                                                       |
| disable_rollback      | True                                                                                                                       |
| deletion_time         | None                                                                                                                       |
| stack_user_project_id | 0d97b86e82234c028d9c5f785aeeb3c9                                                                                           |
| capabilities          | []                                                                                                                         |
| notification_topics   | []                                                                                                                         |
| stack_owner           | None                                                                                                                       |
| timeout_mins          | None                                                                                                                       |
| tags                  | null                                                                                                                       |
|                       | ...                                                                                                                        |
|                       |                                                                                                                            |
+-----------------------+----------------------------------------------------------------------------------------------------------------------------+
openstack stack output list linkstack
+-------------+---------------------------+
| output_key  | description               |
+-------------+---------------------------+
| fip_address | Floating IP address value |
+-------------+---------------------------+
openstack stack output show linkstack fip_address
+--------------+---------------------------+
| Field        | Value                     |
+--------------+---------------------------+
| description  | Floating IP address value |
| output_key   | fip_address               |
| output_value | 172.30.152.22             |
+--------------+---------------------------+
openstack stack resource list linkstack
+---------------+--------------------------------------+---------------------------------+-----------------+----------------------+
| resource_name | physical_resource_id                 | resource_type                   | resource_status | updated_time         |
+---------------+--------------------------------------+---------------------------------+-----------------+----------------------+
| fip           | 732de760-891d-4684-9853-874527c8dfdf | OS::Nova::FloatingIP            | CREATE_COMPLETE | 2020-04-30T14:22:53Z |
| fip_assoc     | 4                                    | OS::Nova::FloatingIPAssociation | CREATE_COMPLETE | 2020-04-30T14:22:53Z |
| link-server   | 4174ee39-6dce-4683-8d7c-8e9a00dc9907 | OS::Nova::Server                | CREATE_COMPLETE | 2020-04-30T14:22:53Z |
+---------------+--------------------------------------+---------------------------------+-----------------+----------------------+

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.