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Chapter 5. Orchestration

The director uses Heat Orchestration Templates (HOT) as a template format for its Overcloud deployment plan. Templates in HOT format are mostly expressed in YAML format. The purpose of a template is to define and create a stack, which is a collection of resources that heat creates, and the configuration of the resources. Resources are objects in OpenStack and can include compute resources, network configuration, security groups, scaling rules, and custom resources.

This chapter provides some basics for understanding the HOT syntax so that you can create your own template files.

5.1. Learning Heat Template Basics

5.1.1. Understanding Heat Templates

The structure of a Heat template has three main sections:

Parameters
These are settings passed to heat, which provides a way to customize a stack, and any default values for parameters without passed values. These are defined in the parameters section of a template.
Resources
These are the specific objects to create and configure as part of a stack. OpenStack contains a set of core resources that span across all components. These are defined in the resources section of a template.
Output
These are values passed from heat after the stack’s creation. You can access these values either through the heat API or client tools. These are defined in the output section of a template.

Here is an example of a basic heat template:

heat_template_version: 2013-05-23

description: > A very basic Heat template.

parameters:
  key_name:
    type: string
    default: lars
    description: Name of an existing key pair to use for the instance
  flavor:
    type: string
    description: Instance type for the instance to be created
    default: m1.small
  image:
    type: string
    default: cirros
    description: ID or name of the image to use for the instance

resources:
  my_instance:
    type: OS::Nova::Server
    properties:
      name: My Cirros Instance
      image: { get_param: image }
      flavor: { get_param: flavor }
      key_name: { get_param: key_name }

output:
  instance_name:
    description: Get the instance's name
    value: { get_attr: [ my_instance, name ] }

This template uses the resource type type: OS::Nova::Server to create an instance called my_instance with a particular flavor, image, and key. The stack can return the value of instance_name, which is called My Cirros Instance.

Important

A Heat template also requires the heat_template_version parameter, which defines the syntax version to use and the functions available. For more information, see the Official Heat Documentation.

5.1.2. Understanding Environment Files

An environment file is a special type of template that provides customization for your Heat templates. This includes three key parts:

Resource Registry
This section defines custom resource names, linked to other heat templates. This essentially provides a method to create custom resources that do not exist within the core resource collection. These are defined in the resource_registry section of an environment file.
Parameters
These are common settings you apply to the top-level template’s parameters. For example, if you have a template that deploys nested stacks, such as resource registry mappings, the parameters only apply to the top-level template and not templates for the nested resources. Parameters are defined in the parameters section of an environment file.
Parameter Defaults
These parameters modify the default values for parameters in all templates. For example, if you have a Heat template that deploys nested stacks, such as resource registry mappings,the parameter defaults apply to all templates. In other words, the top-level template and those defining all nested resources. The parameter defaults are defined in the parameter_defaults section of an environment file.
Important

It is recommended to use parameter_defaults instead of parameters When creating custom environment files for your Overcloud. This is so the parameters apply to all stack templates for the Overcloud.

An example of a basic environment file:

resource_registry:
  OS::Nova::Server::MyServer: myserver.yaml

parameter_defaults:
  NetworkName: my_network

parameters:
  MyIP: 192.168.0.1

For example, this environment file (my_env.yaml) might be included when creating a stack from a certain Heat template (my_template.yaml). The my_env.yaml files creates a new resource type called OS::Nova::Server::MyServer. The myserver.yaml file is a Heat template file that provides an implementation for this resource type that overrides any built-in ones. You can include the OS::Nova::Server::MyServer resource in your my_template.yaml file.

The MyIP applies a parameter only to the main Heat template that deploys along with this environment file. In this example, it only applies to the parameters in my_template.yaml.

The NetworkName applies to both the main Heat template (in this example, my_template.yaml) and the templates associated with resources included the main template, such as the OS::Nova::Server::MyServer resource and its myserver.yaml template in this example.

5.2. Obtaining the Default Director Templates

The director uses an advanced Heat template collection used to create an Overcloud. This collection is available from the openstack group on Github in the openstack-tripleo-heat-templates repository. To obtain a clone of this template collection, run the following command:

$ git clone https://github.com/openstack/tripleo-heat-templates.git
Note

The Red Hat-specific version of this template collection is available from the openstack-tripleo-heat-template package, which installs the collection to /usr/share/openstack-tripleo-heat-templates.

There are many heat templates and environment files in this collection. However, the main files and directories to note in this template collection are:

overcloud.j2.yaml
This is the main template file used to create the Overcloud environment. This file uses Jinja2 syntax to iterate over certain sections in the template to create custom roles. The Jinja2 formatting is rendered into YAML during the overcloud deployment process.
overcloud-resource-registry-puppet.j2.yaml
This is the main environment file used to create the Overcloud environment. It provides a set of configurations for Puppet modules stored on the Overcloud image. After the director writes the Overcloud image to each node, Heat starts the Puppet configuration for each node using the resources registered in this environment file. This file uses Jinja2 syntax to iterate over certain sections in the template to create custom roles. The Jinja2 formatting is rendered into YAML during the overcloud deployment process.
roles_data.yaml
A file that defines the roles in an overcloud and maps services to each role.
capabilities-map.yaml
A mapping of environment files for an overcloud plan. Use this file to describe and enable environment files through the director’s web UI. Custom environment files detected in an overcloud plan but not listed in the capabilities-map.yaml are listed in the Other subtab of 2 Specify Deployment Configuration > Overall Settings on the web UI.
environments
Contains additional Heat environment files that you can use with your Overcloud creation. These environment files enable extra functions for your resulting OpenStack environment. For example, the directory contains an environment file for enabling Cinder NetApp backend storage (cinder-netapp-config.yaml).
network
A set of Heat templates to help create isolated networks and ports.
puppet
Templates mostly driven by configuration with puppet. The aforementioned overcloud-resource-registry-puppet.j2.yaml environment file uses the files in this directory to drive the application of the Puppet configuration on each node.
puppet/services
A directory containing heat templates for all services in the composable service architecture.
extraconfig
Templates used to enable extra functionality. For example, the extraconfig/pre_deploy/rhel-registration director provides the ability to register your nodes' Red Hat Enterprise Linux operating systems to the Red Hat Content Delivery network or your own Red Hat Satellite server.
firstboot
Provides example first_boot scripts that the director uses when initially creating the nodes.

This provides a general overview of the templates the director uses for orchestrating the Overcloud creation. The next few sections show how to create your own custom templates and environment files that you can add to an Overcloud deployment.

5.3. First Boot: Customizing First Boot Configuration

The director provides a mechanism to perform configuration on all nodes upon the initial creation of the Overcloud. The director achieves this through cloud-init, which you can call using the OS::TripleO::NodeUserData resource type.

In this example, you will update the nameserver with a custom IP address on all nodes. You must first create a basic heat template (/home/stack/templates/nameserver.yaml) that runs a script to append each node’s resolv.conf with a specific nameserver. You can use the OS::TripleO::MultipartMime resource type to send the configuration script.

heat_template_version: 2014-10-16

description: >
  Extra hostname configuration

resources:
  userdata:
    type: OS::Heat::MultipartMime
    properties:
      parts:
      - config: {get_resource: nameserver_config}

  nameserver_config:
    type: OS::Heat::SoftwareConfig
    properties:
      config: |
        #!/bin/bash
        echo "nameserver 192.168.1.1" >> /etc/resolv.conf

outputs:
  OS::stack_id:
    value: {get_resource: userdata}

Next, create an environment file (/home/stack/templates/firstboot.yaml) that registers your heat template as the OS::TripleO::NodeUserData resource type.

resource_registry:
  OS::TripleO::NodeUserData: /home/stack/templates/nameserver.yaml

To add the first boot configuration, add the environment file to the stack along with your other environment files when first creating the Overcloud. For example:

$ openstack overcloud deploy --templates \
    ...
    -e /home/stack/templates/firstboot.yaml \
    ...

The -e applies the environment file to the Overcloud stack.

This adds the configuration to all nodes when they are first created and boot for the first time. Subsequent inclusions of these templates, such as updating the Overcloud stack, does not run these scripts.

Important

You can only register the OS::TripleO::NodeUserData to one heat template. Subsequent usage overrides the heat template to use.

This achieves the following:

  1. OS::TripleO::NodeUserData is a director-based Heat resource used in other templates in the collection and applies first boot configuration to all nodes. This resource passes data for use in cloud-init. The default NodeUserData refers to a Heat template that produces a blank value (firstboot/userdata_default.yaml). In our case, our firstboot.yaml environment file replaces this default with a reference to our own nameserver.yaml file.
  2. nameserver_config defines our Bash script to run on first boot. The OS::Heat::SoftwareConfig resource defines it as a piece of configuration to apply.
  3. userdata converts the configuration from nameserver_config into a multi-part MIME message using the OS::Heat::MultipartMime resource.
  4. The outputs provides an output parameter OS::stack_id which takes the MIME message from userdata and provides it to the the Heat template/resource calling it.

As a result, each node runs the following Bash script on its first boot:

#!/bin/bash
echo "nameserver 192.168.1.1" >> /etc/resolve.conf

This example shows how Heat template pass and modfy configuration from one resource to another. It also shows how to use environment files to register new Heat resources or modify existing ones.

5.4. Pre-Configuration: Customizing Specific Overcloud Roles

Important

Previous versions of this document used the OS::TripleO::Tasks::*PreConfig resources to provide pre-configuration hooks on a per role basis. The director’s Heat template collection requires dedicated use of these hooks, which means you should not use them for custom use. Instead, use the OS::TripleO::*ExtraConfigPre hooks outlined below.

The Overcloud uses Puppet for the core configuration of OpenStack components. The director provides a set of hooks to provide custom configuration for specific node roles after the first boot completes and before the core configuration begins. These hooks include:

OS::TripleO::ControllerExtraConfigPre
Additional configuration applied to Controller nodes before the core Puppet configuration.
OS::TripleO::ComputeExtraConfigPre
Additional configuration applied to Compute nodes before the core Puppet configuration.
OS::TripleO::CephStorageExtraConfigPre
Additional configuration applied to Ceph Storage nodes before the core Puppet configuration.
OS::TripleO::ObjectStorageExtraConfigPre
Additional configuration applied to Object Storage nodes before the core Puppet configuration.
OS::TripleO::BlockStorageExtraConfigPre
Additional configuration applied to Block Storage nodes before the core Puppet configuration.
OS::TripleO::[ROLE]ExtraConfigPre
Additional configuration applied to custom nodes before the core Puppet configuration. Replace [ROLE] with the composable role name.

In this example, you first create a basic heat template (/home/stack/templates/nameserver.yaml) that runs a script to write to a node’s resolv.conf with a variable nameserver.

heat_template_version: 2014-10-16

description: >
  Extra hostname configuration

  parameters:
    server:
      type: json
    nameserver_ip:
      type: string
    DeployIdentifier:
      type: string

resources:
  CustomExtraConfigPre:
    type: OS::Heat::SoftwareConfig
    properties:
      group: script
      config:
        str_replace:
          template: |
            #!/bin/sh
            echo "nameserver _NAMESERVER_IP_" > /etc/resolv.conf
          params:
            _NAMESERVER_IP_: {get_param: nameserver_ip}

  CustomExtraDeploymentPre:
    type: OS::Heat::SoftwareDeployment
    properties:
      server: {get_param: server}
      config: {get_resource: CustomExtraConfigPre}
      actions: ['CREATE','UPDATE']
      input_values:
        deploy_identifier: {get_param: DeployIdentifier}

outputs:
  deploy_stdout:
    description: Deployment reference, used to trigger pre-deploy on changes
    value: {get_attr: [CustomExtraDeploymentPre, deploy_stdout]}

In this example, the resources section contains the following:

CustomExtraConfigPre
This defines a software configuration. In this example, we define a Bash script and Heat replaces _NAMESERVER_IP_ with the value stored in the nameserver_ip parameter.
CustomExtraDeploymentPre

This executes a software configuration, which is the software configuration from the CustomExtraConfigPre resource. Note the following:

  • The config parameter makes a reference to the CustomExtraConfigPre resource so Heat knows what configuration to apply.
  • The server parameter retrieves a map of the Overcloud nodes. This parameter is provided by the parent template and is mandatory in templates for this hook.
  • The actions parameter defines when to apply the configuration. In this case, we only apply the configuration when the Overcloud is created. Possible actions include CREATE, UPDATE, DELETE, SUSPEND, and RESUME.
  • input_values contains a parameter called deploy_identifier, which stores the DeployIdentifier from the parent template. This parameter provides a timestamp to the resource for each deployment update. This ensures the resource reapplies on subsequent overcloud updates.

Next, create an environment file (/home/stack/templates/pre_config.yaml) that registers your heat template to the role-based resource type. For example, to apply only to Controller nodes, use the ControllerExtraConfigPre hook:

resource_registry:
  OS::TripleO::ControllerExtraConfigPre: /home/stack/templates/nameserver.yaml

parameter_defaults:
  nameserver_ip: 192.168.1.1

To apply the configuration, add the environment file to the stack along with your other environment files when creating or updating the Overcloud. For example:

$ openstack overcloud deploy --templates \
    ...
    -e /home/stack/templates/pre_config.yaml \
    ...

This applies the configuration to all Controller nodes before the core configuration begins on either the initial Overcloud creation or subsequent updates.

Important

You can only register each resource to only one Heat template per hook. Subsequent usage overrides the Heat template to use.

This achieves the following:

  1. OS::TripleO::ControllerExtraConfigPre is a director-based Heat resource used in the configuration templates in the Heat template collection. This resource passes configuration to each Controller node. The default ControllerExtraConfigPre refers to a Heat template that produces a blank value (puppet/extraconfig/pre_deploy/default.yaml). In our case, our pre_config.yaml environment file replaces this default with a reference to our own nameserver.yaml file.
  2. The environment file also passes the nameserver_ip as a parameter_default value for our environment. This is a parameter that stores the IP address of our nameserver. The nameserver.yaml Heat template then accepts this parameter as defined in the parameters section.
  3. The template defines CustomExtraConfigPre as a configuration resource through OS::Heat::SoftwareConfig. Note the group: script property. The group defines the software configuration tool to use, which are available through a set of hooks for Heat. In this case, the script hook runs an executable script that you define in the SoftwareConfig resource as the config property.
  4. The script itself appends /etc/resolve.conf with the nameserver IP address. Note the str_replace attribute, which allows you to replace variables in the template section with parameters in the params section. In this case, we set the NAMESERVER_IP to the nameserver IP address, which substitutes the same variable in the script. This results in the following script:

    #!/bin/sh
    echo "nameserver 192.168.1.1" >> /etc/resolve.conf

This example shows how to create a Heat template that defines a configuration and deploys it using the OS::Heat::SoftwareConfig and OS::Heat::SoftwareDeployments before the core configuration. It also shows how to define parameters in your environment file and pass them to templates in the configuration.

5.5. Pre-Configuration: Customizing All Overcloud Roles

The Overcloud uses Puppet for the core configuration of OpenStack components. The director provides a hook to configure all node types after the first boot completes and before the core configuration begins:

OS::TripleO::NodeExtraConfig
Additional configuration applied to all nodes roles before the core Puppet configuration.

In this example, you first create a basic heat template (/home/stack/templates/nameserver.yaml) that runs a script to append each node’s resolv.conf with a variable nameserver.

heat_template_version: 2014-10-16

description: >
  Extra hostname configuration

parameters:
  server:
    type: string
  nameserver_ip:
    type: string
  DeployIdentifier:
    type: string

resources:
  CustomExtraConfigPre:
    type: OS::Heat::SoftwareConfig
    properties:
      group: script
      config:
        str_replace:
          template: |
            #!/bin/sh
            echo "nameserver _NAMESERVER_IP_" >> /etc/resolv.conf
          params:
            _NAMESERVER_IP_: {get_param: nameserver_ip}

  CustomExtraDeploymentPre:
    type: OS::Heat::SoftwareDeployment
    properties:
      server: {get_param: server}
      config: {get_resource: CustomExtraConfigPre}
      actions: ['CREATE','UPDATE']
      input_values:
        deploy_identifier: {get_param: DeployIdentifier}

outputs:
  deploy_stdout:
    description: Deployment reference, used to trigger pre-deploy on changes
    value: {get_attr: [CustomExtraDeploymentPre, deploy_stdout]}

In this example, the resources section contains the following:

CustomExtraConfigPre
This defines a software configuration. In this example, we define a Bash script and Heat replaces _NAMESERVER_IP_ with the value stored in the nameserver_ip parameter.
CustomExtraDeploymentPre

This executes a software configuration, which is the software configuration from the CustomExtraConfigPre resource. Note the following:

  • The config parameter makes a reference to the CustomExtraConfigPre resource so Heat knows what configuration to apply.
  • The server parameter retrieves a map of the Overcloud nodes. This parameter is provided by the parent template and is mandatory in templates for this hook.
  • The actions parameter defines when to apply the configuration. In this case, we only apply the configuration when the Overcloud is created. Possible actions include CREATE, UPDATE, DELETE, SUSPEND, and RESUME.
  • The input_values parameter contains a sub-parameter called deploy_identifier, which stores the DeployIdentifier from the parent template. This parameter provides a timestamp to the resource for each deployment update. This ensures the resource reapplies on subsequent overcloud updates.

Next, create an environment file (/home/stack/templates/pre_config.yaml) that registers your heat template as the OS::TripleO::NodeExtraConfig resource type.

resource_registry:
  OS::TripleO::NodeExtraConfig: /home/stack/templates/nameserver.yaml

parameter_defaults:
  nameserver_ip: 192.168.1.1

To apply the configuration, add the environment file to the stack along with your other environment files when creating or updating the Overcloud. For example:

$ openstack overcloud deploy --templates \
    ...
    -e /home/stack/templates/pre_config.yaml \
    ...

This applies the configuration to all nodes before the core configuration begins on either the initial Overcloud creation or subsequent updates.

Important

You can only register the OS::TripleO::NodeExtraConfig to only one Heat template. Subsequent usage overrides the Heat template to use.

This achieves the following:

  1. OS::TripleO::NodeExtraConfig is a director-based Heat resource used in the configuration templates in the Heat template collection. This resource passes configuration to each node. The default NodeExtraConfig refers to a Heat template that produces a blank value (puppet/extraconfig/pre_deploy/default.yaml). In our case, our pre_config.yaml environment file replaces this default with a reference to our own nameserver.yaml file.
  2. The environment file also passes the nameserver_ip as a parameter_default value for our environment. This is a parameter that stores the IP address of our nameserver. The nameserver.yaml Heat template then accepts this parameter as defined in the parameters section.
  3. The template defines CustomExtraConfigPre as a configuration resource through OS::Heat::SoftwareConfig. Note the group: script property. The group defines the software configuration tool to use, which are available through a set of hooks for Heat. In this case, the script hook runs an executable script that you define in the SoftwareConfig resource as the config property.
  4. The script itself appends /etc/resolve.conf with the nameserver IP address. Note the str_replace attribute, which allows you to replace variables in the template section with parameters in the params section. In this case, we set the NAMESERVER_IP to the nameserver IP address, which substitutes the same variable in the script. This results in the following script:

    #!/bin/sh
    echo "nameserver 192.168.1.1" >> /etc/resolve.conf

This example shows how to create a Heat template that defines a configuration and deploys it using the OS::Heat::SoftwareConfig and OS::Heat::SoftwareDeployments before the core configuration. It also shows how to define parameters in your environment file and pass them to templates in the configuration.

5.6. Post-Configuration: Customizing All Overcloud Roles

Important

Previous versions of this document used the OS::TripleO::Tasks::*PostConfig resources to provide post-configuration hooks on a per role basis. The director’s Heat template collection requires dedicated use of these hooks, which means you should not use them for custom use. Instead, use the OS::TripleO::NodeExtraConfigPost hook outlined below.

A situation might occur where you have completed the creation of your Overcloud but want to add additional configuration to all roles, either on initial creation or on a subsequent update of the Overcloud. In this case, you use the following post-configuration hook:

OS::TripleO::NodeExtraConfigPost
Additional configuration applied to all nodes roles after the core Puppet configuration.

In this example, you first create a basic heat template (/home/stack/templates/nameserver.yaml) that runs a script to append each node’s resolv.conf with a variable nameserver.

heat_template_version: 2014-10-16

description: >
  Extra hostname configuration

parameters:
  servers:
    type: json
  nameserver_ip:
    type: string
  DeployIdentifier:
    type: string

resources:
  CustomExtraConfig:
    type: OS::Heat::SoftwareConfig
    properties:
      group: script
      config:
        str_replace:
          template: |
            #!/bin/sh
            echo "nameserver _NAMESERVER_IP_" >> /etc/resolv.conf
          params:
            _NAMESERVER_IP_: {get_param: nameserver_ip}

  CustomExtraDeployments:
    type: OS::Heat::SoftwareDeploymentGroup
    properties:
      servers:  {get_param: servers}
      config: {get_resource: CustomExtraConfig}
      actions: ['CREATE','UPDATE']
      input_values:
        deploy_identifier: {get_param: DeployIdentifier}

In this example, the resources section contains the following:

CustomExtraConfig
This defines a software configuration. In this example, we define a Bash script and Heat replaces _NAMESERVER_IP_ with the value stored in the nameserver_ip parameter.
CustomExtraDeployments

This executes a software configuration, which is the software configuration from the CustomExtraConfig resource. Note the following:

  • The config parameter makes a reference to the CustomExtraConfig resource so Heat knows what configuration to apply.
  • The servers parameter retrieves a map of the Overcloud nodes. This parameter is provided by the parent template and is mandatory in templates for this hook.
  • The actions parameter defines when to apply the configuration. In this case, we only apply the configuration when the Overcloud is created. Possible actions include CREATE, UPDATE, DELETE, SUSPEND, and RESUME.
  • input_values contains a parameter called deploy_identifier, which stores the DeployIdentifier from the parent template. This parameter provides a timestamp to the resource for each deployment update. This ensures the resource reapplies on subsequent overcloud updates.

Next, create an environment file (/home/stack/templates/post_config.yaml) that registers your heat template as the OS::TripleO::NodeExtraConfigPost: resource type.

resource_registry:
  OS::TripleO::NodeExtraConfigPost: /home/stack/templates/nameserver.yaml

parameter_defaults:
  nameserver_ip: 192.168.1.1

To apply the configuration, add the environment file to the stack along with your other environment files when creating or updating the Overcloud. For example:

$ openstack overcloud deploy --templates \
    ...
    -e /home/stack/templates/post_config.yaml \
    ...

This applies the configuration to all nodes after the core configuration completes on either initial Overcloud creation or subsequent updates.

Important

You can only register the OS::TripleO::NodeExtraConfigPost to only one Heat template. Subsequent usage overrides the Heat template to use.

This achieves the following:

  1. OS::TripleO::NodeExtraConfigPost is a director-based Heat resource used in the post-configuration templates in the collection. This resource passes configuration to each node type through the *-post.yaml templates. The default NodeExtraConfigPost refers to a Heat template that produces a blank value (extraconfig/post_deploy/default.yaml). In our case, our post_config.yaml environment file replaces this default with a reference to our own nameserver.yaml file.
  2. The environment file also passes the nameserver_ip as a parameter_default value for our environment. This is a parameter that stores the IP address of our nameserver. The nameserver.yaml Heat template then accepts this parameter as defined in the parameters section.
  3. The template defines CustomExtraConfig as a configuration resource through OS::Heat::SoftwareConfig. Note the group: script property. The group defines the software configuration tool to use, which are available through a set of hooks for Heat. In this case, the script hook runs an executable script that your define in the SoftwareConfig resource as the config property.
  4. The script itself appends /etc/resolve.conf with the nameserver IP address. Note the str_replace attribute, which allows you to replace variables in the template section with parameters in the params section. In this case, we set the NAMESERVER_IP to the nameserver IP address, which substitutes the same variable in the script. This results in the following script:

    #!/bin/sh
    echo "nameserver 192.168.1.1" >> /etc/resolve.conf

This example shows how to create a Heat template that defines a configuration and deploys it using the OS::Heat::SoftwareConfig and OS::Heat::SoftwareDeployments. It also shows how to define parameters in your environment file and pass them to templates in the configuration.

5.7. Puppet: Applying Custom Configuration to an Overcloud

Previously, we discussed adding configuration for a new backend to OpenStack Puppet modules. This section show how the director executes the application of new configuration.

Heat templates provide a hook allowing you to apply Puppet configuration with a OS::Heat::SoftwareConfig resource. The process is similar to how we include and execute Bash scripts. However, instead of the group: script hook, we use the group: puppet hook.

For example, you might have a Puppet manifest (example-puppet-manifest.pp) that enables an NFS Cinder backend using the official Cinder Puppet Module:

cinder::backend::nfs { 'mynfsserver':
  nfs_servers          => ['192.168.1.200:/storage'],
}

This Puppet configuration creates a new resource using the cinder::backend::nfs defined type. To apply this resource through Heat, create a basic Heat template (puppet-config.yaml) that runs our Puppet manifest:

heat_template_version: 2014-10-16

parameters:
  servers:
    type: json

resources:
  ExtraPuppetConfig:
    type: OS::Heat::SoftwareConfig
    properties:
      group: puppet
      config:
        get_file: example-puppet-manifest.pp
      options:
        enable_hiera: True
        enable_facter: False

  ExtraPuppetDeployment:
    type: OS::Heat::SoftwareDeployments
    properties:
      config: {get_resource: ExtraPuppetConfig}
      servers: {get_param: servers}
      actions: ['CREATE','UPDATE']

Next, create an environment file (puppet_config.yaml) that registers our Heat template as the OS::TripleO::NodeExtraConfigPost resource type.

resource_registry:
  OS::TripleO::NodeExtraConfigPost: puppet_config.yaml

This example is similar to using SoftwareConfig and SoftwareDeployments from the script hook example in the previous section. However, there are some differences in this example:

  1. We set group: puppet so that we execute the puppet hook.
  2. The config attribute uses the get_file attribute to refer to a Puppet manifest that contains our additional configuration.
  3. The options attribute contains some options specific to Puppet configurations:

    • The enable_hiera option enables the Puppet configuration to use Hiera data.
    • The enable_facter option enables the Puppet configuration to use system facts from the facter command.

This example shows how to include a Puppet manifest as part of the software configuration for the Overcloud. This provides a way to apply certain configuration classes from existing Puppet modules on the Overcloud images, which helps you customize your Overcloud to use certain software and hardware.

5.8. Puppet: Customizing Hieradata for Roles

The Heat template collection contains a set of parameters to pass extra configuration to certain node types. These parameters save the configuration as hieradata for the node’s Puppet configuration. These parameters are:

ControllerExtraConfig
Configuration to add to all Controller nodes.
NovaComputeExtraConfig
Configuration to add to all Compute nodes.
BlockStorageExtraConfig
Configuration to add to all Block Storage nodes.
ObjectStorageExtraConfig
Configuration to add to all Object Storage nodes
CephStorageExtraConfig
Configuration to add to all Ceph Storage nodes
[ROLE]ExtraConfig
Configuration to add to a composable role. Replace [ROLE] with the composable role name.
ExtraConfig
Configuration to add to all nodes.

To add extra configuration to the post-deployment configuration process, create an environment file that contains these parameters in the parameter_defaults section. For example, to increase the reserved memory for Compute hosts to 1024 MB and set the VNC keymap to Japanese:

parameter_defaults:
  NovaComputeExtraConfig:
    nova::compute::reserved_host_memory: 1024
    nova::compute::vnc_keymap: ja

Include this environment file when running openstack overcloud deploy.

Important

You can only define each parameter once. Subsequent usage overrides previous values.

5.9. Adding Environment Files to an Overcloud Deployment

After developing a set of environment files relevant to your custom configuration, include these files in your Overcloud deployment. This means running the openstack overcloud deploy command with the -e option, followed by the environment file. You can specify the -e option as many times as necessary for your customization. For example:

$ openstack overcloud deploy --templates -e network-configuration.yaml -e storage-configuration.yaml -e first-boot.yaml
Important

Environment files are stacked in consecutive order. This means that each subsequent file stacks upon both the main Heat template collection and all previous environment files. This provides a way to override resource definitions. For example, if all environment files in an Overcloud deployment define the NodeExtraConfigPost resource, then Heat uses NodeExtraConfigPost defined in the last environment file. As a result, the order of the environment files is important. Make sure to order your environment files so they are processed and stacked correctly.

Warning

Any environment files added to the Overcloud using the -e option become part of your Overcloud’s stack definition. The director requires these environment files for any post-deployment or re-deployment functions. Failure to include these files can result in damage to your Overcloud.