Chapter 6. Composable services and custom roles

Procedure

1. List the default role templates:

   $ openstack overcloud roles list
   BlockStorage
   CephStorage
   Compute
   ComputeHCI
   ComputeOvsDpdk
   Controller
   ...

2. View the role definition in YAML format with the openstack overcloud roles show command:

   $ openstack overcloud roles show Compute

3. Generate a custom roles_data file. Use the openstack overcloud roles generate command to join multiple predefined roles into a single file. For example, run the following command to generate a roles_data.yaml file that contains the Controller, Compute, and Networker roles:

   $ openstack overcloud roles generate -o ~/roles_data.yaml Controller Compute Networker

   Use the -o option to define the name out of the output file.

   This command creates a custom roles_data file. However, the previous example uses the Controller and Networker roles, which both contain the same networking agents. This means that the networking services scale from the Controller role to the Networker role and the overcloud balances the load for networking services between the Controller and Networker nodes.

   To make this Networker role standalone, you can create your own custom Controller role, as well as any other role that you require. This allows you to generate a roles_data file from your own custom roles.

4. Copy the directory from the core heat template collection to the home directory of the stack user:

   $ cp -r /usr/share/openstack-tripleo-heat-templates/roles ~/.

5. Add or modify the custom role files in this directory. Use the --roles-path option with any of the role sub-commands to use this directory as the source for your custom roles:

   $ openstack overcloud roles generate -o my_roles_data.yaml \
     --roles-path ~/roles \
     Controller Compute Networker

   This command generates a single my_roles_data.yaml file from the individual roles in the ~/roles directory.

Procedure

1. Create a custom copy of the default roles directory:

   $ cp -r /usr/share/openstack-tripleo-heat-templates/roles ~/.

2. Create a new file called ~/roles/Horizon.yaml and create a new Horizon role that contains base and core OpenStack Dashboard services:

   - name: Horizon
     CountDefault: 1
     HostnameFormatDefault: '%stackname%-horizon-%index%'
     ServicesDefault:
       - OS::TripleO::Services::CACerts
       - OS::TripleO::Services::Kernel
       - OS::TripleO::Services::Ntp
       - OS::TripleO::Services::Snmp
       - OS::TripleO::Services::Sshd
       - OS::TripleO::Services::Timezone
       - OS::TripleO::Services::TripleoPackages
       - OS::TripleO::Services::TripleoFirewall
       - OS::TripleO::Services::SensuClient
       - OS::TripleO::Services::FluentdClient
       - OS::TripleO::Services::AuditD
       - OS::TripleO::Services::Collectd
       - OS::TripleO::Services::MySQLClient
       - OS::TripleO::Services::Apache
       - OS::TripleO::Services::Horizon

   • Set the name parameter to the name of the custom role. Custom role names have a maximum length of 47 characters.
   • Set the CountDefault parameter to 1 so that a default overcloud always includes the Horizon node.

3. Optional: If you want to scale the services in an existing overcloud, retain the existing services on the Controller role. If you want to create a new overcloud and you want the OpenStack Dashboard to remain on the standalone role, remove the OpenStack Dashboard components from the Controller role definition:

   - name: Controller
     CountDefault: 1
     ServicesDefault:
       ...
       - OS::TripleO::Services::GnocchiMetricd
       - OS::TripleO::Services::GnocchiStatsd
       - OS::TripleO::Services::HAproxy
       - OS::TripleO::Services::HeatApi
       - OS::TripleO::Services::HeatApiCfn
       - OS::TripleO::Services::HeatApiCloudwatch
       - OS::TripleO::Services::HeatEngine
       # - OS::TripleO::Services::Horizon                # Remove this service
       - OS::TripleO::Services::IronicApi
       - OS::TripleO::Services::IronicConductor
       - OS::TripleO::Services::Iscsid
       - OS::TripleO::Services::Keepalived
       ...

4. Generate the new roles_data-horizon.yaml file using the ~/roles directory as the source:

   $ openstack overcloud roles generate -o roles_data-horizon.yaml \
     --roles-path ~/roles \
     Controller Compute Horizon

5. Define a new flavor for this role so that you can tag specific nodes. For this example, use the following commands to create a horizon flavor:

   1. Create a horizon flavor:

      (undercloud)$ openstack flavor create --id auto --ram 6144 --disk 40 --vcpus 4 horizon

      Note

      These properties are not used for scheduling instances, however, the Compute scheduler does use the disk size to determine the root partition size.

   2. Tag each bare metal node that you want to designate for the Dashboard service (horizon) with a custom resource class:

      (undercloud)$ openstack baremetal node set --resource-class baremetal.HORIZON <NODE>

      Replace <NODE> with the ID of the bare metal node.

   3. Associate the horizon flavor with the custom resource class:

      (undercloud)$ openstack flavor set --property resources:CUSTOM_BAREMETAL_HORIZON=1 horizon

      To determine the name of a custom resource class that corresponds to a resource class of a bare metal node, convert the resource class to uppercase, replace punctuation with an underscore, and prefix the value with CUSTOM_.

      Note

      A flavor can request only one instance of a bare metal resource class.

   4. Set the following flavor properties to prevent the Compute scheduler from using the bare metal flavor properties for scheduling instances:

      (undercloud)$ openstack flavor set --property resources:VCPU=0 --property resources:MEMORY_MB=0 --property resources:DISK_GB=0 horizon

6. Define the Horizon node count and flavor using the following environment file snippet:

   parameter_defaults:
     OvercloudHorizonFlavor: horizon
     HorizonCount: 1

7. Include the new roles_data-horizon.yaml file and environment file in the openstack overcloud deploy command, along with any other environment files relevant to your deployment:

   $ openstack overcloud deploy --templates -r ~/templates/roles_data-horizon.yaml -e ~/templates/node-count-flavor.yaml

   This configuration creates a three-node overcloud that consists of one Controller node, one Compute node, and one Networker node. To view the list of nodes in your overcloud, run the following command:

   $ openstack server list

Procedure

1. Create a custom copy of the default roles directory:

   $ cp -r /usr/share/openstack-tripleo-heat-templates/roles ~/.

2. Edit the ~/roles/Controller.yaml file and modify the service list for the ServicesDefault parameter. Scroll to the OpenStack Orchestration services and remove them:

       - OS::TripleO::Services::GlanceApi
       - OS::TripleO::Services::GlanceRegistry
       - OS::TripleO::Services::HeatApi            # Remove this service
       - OS::TripleO::Services::HeatApiCfn         # Remove this service
       - OS::TripleO::Services::HeatApiCloudwatch  # Remove this service
       - OS::TripleO::Services::HeatEngine         # Remove this service
       - OS::TripleO::Services::MySQL
       - OS::TripleO::Services::NeutronDhcpAgent

3. Generate the new roles_data file:

   $ openstack overcloud roles generate -o roles_data-no_heat.yaml \
     --roles-path ~/roles \
     Controller Compute Networker

4. Include this new roles_data file when you run the openstack overcloud deploy command:

   $ openstack overcloud deploy --templates -r ~/templates/roles_data-no_heat.yaml

   This command deploys an overcloud without OpenStack Orchestration services installed on the Controller nodes.

Procedure

1. Add an entry in an environment file that links the CinderBackup service to the heat template that contains the cinder-backup configuration:

   resource_registry:
     OS::TripleO::Services::CinderBackup: ../podman/services/pacemaker/cinder-backup.yaml
   ...

   This entry overrides the default null operation resource and enables the service.

2. Include this environment file when you run the openstack overcloud deploy command:

   $ openstack overcloud deploy --templates -e /usr/share/openstack-tripleo-heat-templates/environments/cinder-backup.yaml

Procedure

1. Create a generic role in your custom roles_data.yaml file that does not contain a ServicesDefault list:

   - name: Generic
   - name: Controller
     CountDefault: 1
     ServicesDefault:
       - OS::TripleO::Services::AuditD
       - OS::TripleO::Services::CACerts
       - OS::TripleO::Services::CephClient
       ...
   - name: Compute
     CountDefault: 1
     ServicesDefault:
       - OS::TripleO::Services::AuditD
       - OS::TripleO::Services::CACerts
       - OS::TripleO::Services::CephClient
       ...

   Ensure that you retain the existing Controller and Compute roles.

2. Create an environment file generic-node-params.yaml to specify how many generic Red Hat Enterprise Linux 8 nodes you require and the flavor when selecting nodes to provision:

   parameter_defaults:
     OvercloudGenericFlavor: baremetal
     GenericCount: 1

3. Include both the roles file and the environment file when you run the openstack overcloud deploy command:

   $ openstack overcloud deploy --templates \
   -r ~/templates/roles_data_with_generic.yaml \
   -e ~/templates/generic-node-params.yaml

   This configuration deploys a three-node environment with one Controller node, one Compute node, and one generic Red Hat Enterprise Linux 8 node.