Creating a compute machine set on OpenStack

You can create a different compute machine set to serve a specific purpose in your OKD cluster on OpenStack. For example, you might create infrastructure machine sets and related machines so that you can move supporting workloads to the new machines.

This process is not applicable for clusters with manually provisioned machines. You can use the advanced machine management and scaling capabilities only in clusters where the Machine API is operational.

Machine API overview

The Machine API is a combination of primary resources that are based on the upstream Cluster API project and custom OKD resources.

For OKD 4.12 clusters, the Machine API performs all node host provisioning management actions after the cluster installation finishes. Because of this system, OKD 4.12 offers an elastic, dynamic provisioning method on top of public or private cloud infrastructure.

The two primary resources are:

Machines

A fundamental unit that describes the host for a node. A machine has a providerSpec specification, which describes the types of compute nodes that are offered for different cloud platforms. For example, a machine type for a worker node on Amazon Web Services (AWS) might define a specific machine type and required metadata.

Machine sets

MachineSet resources are groups of compute machines. Compute machine sets are to compute machines as replica sets are to pods. If you need more compute machines or must scale them down, you change the replicas field on the MachineSet resource to meet your compute need.

Control plane machines cannot be managed by compute machine sets.

Control plane machine sets provide management capabilities for supported control plane machines that are similar to what compute machine sets provide for compute machines.

For more information, see “Managing control plane machines”.

The following custom resources add more capabilities to your cluster:

Machine autoscaler

The MachineAutoscaler resource automatically scales compute machines in a cloud. You can set the minimum and maximum scaling boundaries for nodes in a specified compute machine set, and the machine autoscaler maintains that range of nodes.

The MachineAutoscaler object takes effect after a ClusterAutoscaler object exists. Both ClusterAutoscaler and MachineAutoscaler resources are made available by the ClusterAutoscalerOperator object.

Cluster autoscaler

This resource is based on the upstream cluster autoscaler project. In the OKD implementation, it is integrated with the Machine API by extending the compute machine set API. You can use the cluster autoscaler to manage your cluster in the following ways:

  • Set cluster-wide scaling limits for resources such as cores, nodes, memory, and GPU

  • Set the priority so that the cluster prioritizes pods and new nodes are not brought online for less important pods

  • Set the scaling policy so that you can scale up nodes but not scale them down

Machine health check

The MachineHealthCheck resource detects when a machine is unhealthy, deletes it, and, on supported platforms, makes a new machine.

In OKD version 3.11, you could not roll out a multi-zone architecture easily because the cluster did not manage machine provisioning. Beginning with OKD version 4.1, this process is easier. Each compute machine set is scoped to a single zone, so the installation program sends out compute machine sets across availability zones on your behalf. And then because your compute is dynamic, and in the face of a zone failure, you always have a zone for when you must rebalance your machines. In global Azure regions that do not have multiple availability zones, you can use availability sets to ensure high availability. The autoscaler provides best-effort balancing over the life of a cluster.

Sample YAML for a compute machine set custom resource on OpenStack

This sample YAML defines a compute machine set that runs on OpenStack and creates nodes that are labeled with node-role.kubernetes.io/<role>: "".

In this sample, <infrastructure_id> is the infrastructure ID label that is based on the cluster ID that you set when you provisioned the cluster, and <role> is the node label to add.

  1. apiVersion: machine.openshift.io/v1beta1
  2. kind: MachineSet
  3. metadata:
  4.   labels:
  5.     machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
  6.     machine.openshift.io/cluster-api-machine-role: <role> (2)
  7.     machine.openshift.io/cluster-api-machine-type: <role> (2)
  8.   name: <infrastructure_id>-<role> (3)
  9.   namespace: openshift-machine-api
  10. spec:
  11.   replicas: <number_of_replicas>
  12.   selector:
  13.     matchLabels:
  14.       machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
  15.       machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role> (3)
  16.   template:
  17.     metadata:
  18.       labels:
  19.         machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
  20.         machine.openshift.io/cluster-api-machine-role: <role> (2)
  21.         machine.openshift.io/cluster-api-machine-type: <role> (2)
  22.         machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role> (3)
  23.     spec:
  24.       providerSpec:
  25.         value:
  26.           apiVersion: openstackproviderconfig.openshift.io/v1alpha1
  27.           cloudName: openstack
  28.           cloudsSecret:
  29.             name: openstack-cloud-credentials
  30.             namespace: openshift-machine-api
  31.           flavor: <nova_flavor>
  32.           image: <glance_image_name_or_location>
  33.           serverGroupID: <optional_UUID_of_server_group> (4)
  34.           kind: OpenstackProviderSpec
  35.           networks: (5)
  36.           - filter: {}
  37.             subnets:
  38.             - filter:
  39.                 name: <subnet_name>
  40.                 tags: openshiftClusterID=<infrastructure_id> (1)
  41.           primarySubnet: <rhosp_subnet_UUID> (6)
  42.           securityGroups:
  43.           - filter: {}
  44.             name: <infrastructure_id>-worker (1)
  45.           serverMetadata:
  46.             Name: <infrastructure_id>-worker (1)
  47.             openshiftClusterID: <infrastructure_id> (1)
  48.           tags:
  49.           - openshiftClusterID=<infrastructure_id> (1)
  50.           trunk: true
  51.           userDataSecret:
  52.             name: worker-user-data (2)
  53.           availabilityZone: <optional_openstack_availability_zone>
1Specify the infrastructure ID that is based on the cluster ID that you set when you provisioned the cluster. If you have the OpenShift CLI installed, you can obtain the infrastructure ID by running the following command:
  1. $ oc get -o jsonpath=’{.status.infrastructureName}{“\n”}’ infrastructure cluster
2Specify the node label to add.
3Specify the infrastructure ID and node label.
4To set a server group policy for the MachineSet, enter the value that is returned from creating a server group. For most deployments, anti-affinity or soft-anti-affinity policies are recommended.
5Required for deployments to multiple networks. To specify multiple networks, add another entry in the networks array. Also, you must include the network that is used as the primarySubnet value.
6Specify the OpenStack subnet that you want the endpoints of nodes to be published on. Usually, this is the same subnet that is used as the value of machinesSubnet in the install-config.yaml file.

Sample YAML for a compute machine set custom resource that uses SR-IOV on OpenStack

If you configured your cluster for single-root I/O virtualization (SR-IOV), you can create compute machine sets that use that technology.

This sample YAML defines a compute machine set that uses SR-IOV networks. The nodes that it creates are labeled with node-role.openshift.io/<node_role>: ""

In this sample, infrastructure_id is the infrastructure ID label that is based on the cluster ID that you set when you provisioned the cluster, and node_role is the node label to add.

The sample assumes two SR-IOV networks that are named “radio” and “uplink”. The networks are used in port definitions in the spec.template.spec.providerSpec.value.ports list.

Only parameters that are specific to SR-IOV deployments are described in this sample. To review a more general sample, see “Sample YAML for a compute machine set custom resource on OpenStack”.

An example compute machine set that uses SR-IOV networks

  1. apiVersion: machine.openshift.io/v1beta1
  2. kind: MachineSet
  3. metadata:
  4.   labels:
  5.     machine.openshift.io/cluster-api-cluster: <infrastructure_id>
  6.     machine.openshift.io/cluster-api-machine-role: <node_role>
  7.     machine.openshift.io/cluster-api-machine-type: <node_role>
  8.   name: <infrastructure_id>-<node_role>
  9.   namespace: openshift-machine-api
  10. spec:
  11.   replicas: <number_of_replicas>
  12.   selector:
  13.     matchLabels:
  14.       machine.openshift.io/cluster-api-cluster: <infrastructure_id>
  15.       machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<node_role>
  16.   template:
  17.     metadata:
  18.       labels:
  19.         machine.openshift.io/cluster-api-cluster: <infrastructure_id>
  20.         machine.openshift.io/cluster-api-machine-role: <node_role>
  21.         machine.openshift.io/cluster-api-machine-type: <node_role>
  22.         machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<node_role>
  23.     spec:
  24.       metadata:
  25.       providerSpec:
  26.         value:
  27.           apiVersion: openstackproviderconfig.openshift.io/v1alpha1
  28.           cloudName: openstack
  29.           cloudsSecret:
  30.             name: openstack-cloud-credentials
  31.             namespace: openshift-machine-api
  32.           flavor: <nova_flavor>
  33.           image: <glance_image_name_or_location>
  34.           serverGroupID: <optional_UUID_of_server_group>
  35.           kind: OpenstackProviderSpec
  36.           networks:
  37.             - subnets:
  38.               - UUID: <machines_subnet_UUID>
  39.           ports:
  40.             - networkID: <radio_network_UUID> (1)
  41.               nameSuffix: radio
  42.               fixedIPs:
  43.                 - subnetID: <radio_subnet_UUID> (2)
  44.               tags:
  45.                 - sriov
  46.                 - radio
  47.               vnicType: direct (3)
  48.               portSecurity: false (4)
  49.             - networkID: <uplink_network_UUID> (1)
  50.               nameSuffix: uplink
  51.               fixedIPs:
  52.                 - subnetID: <uplink_subnet_UUID> (2)
  53.               tags:
  54.                 - sriov
  55.                 - uplink
  56.               vnicType: direct (3)
  57.               portSecurity: false (4)
  58.           primarySubnet: <machines_subnet_UUID>
  59.           securityGroups:
  60.           - filter: {}
  61.             name: <infrastructure_id>-<node_role>
  62.           serverMetadata:
  63.             Name: <infrastructure_id>-<node_role>
  64.             openshiftClusterID: <infrastructure_id>
  65.           tags:
  66.           - openshiftClusterID=<infrastructure_id>
  67.           trunk: true
  68.           userDataSecret:
  69.             name: <node_role>-user-data
  70.           availabilityZone: <optional_openstack_availability_zone>
1Enter a network UUID for each port.
2Enter a subnet UUID for each port.
3The value of the vnicType parameter must be direct for each port.
4The value of the portSecurity parameter must be false for each port.

You cannot set security groups and allowed address pairs for ports when port security is disabled. Setting security groups on the instance applies the groups to all ports that are attached to it.

After you deploy compute machines that are SR-IOV-capable, you must label them as such. For example, from a command line, enter:

  1. $ oc label node <NODE_NAME> feature.node.kubernetes.io/network-sriov.capable=”true”

Trunking is enabled for ports that are created by entries in the networks and subnets lists. The names of ports that are created from these lists follow the pattern <machine_name>-<nameSuffix>. The nameSuffix field is required in port definitions.

You can enable trunking for each port.

Optionally, you can add tags to ports as part of their tags lists.

Additional resources

Sample YAML for SR-IOV deployments where port security is disabled

To create single-root I/O virtualization (SR-IOV) ports on a network that has port security disabled, define a compute machine set that includes the ports as items in the spec.template.spec.providerSpec.value.ports list. This difference from the standard SR-IOV compute machine set is due to the automatic security group and allowed address pair configuration that occurs for ports that are created by using the network and subnet interfaces.

Ports that you define for machines subnets require:

  • Allowed address pairs for the API and ingress virtual IP ports

  • The compute security group

  • Attachment to the machines network and subnet

Only parameters that are specific to SR-IOV deployments where port security is disabled are described in this sample. To review a more general sample, see Sample YAML for a compute machine set custom resource that uses SR-IOV on OpenStack”.

An example compute machine set that uses SR-IOV networks and has port security disabled

  1. apiVersion: machine.openshift.io/v1beta1
  2. kind: MachineSet
  3. metadata:
  4.   labels:
  5.     machine.openshift.io/cluster-api-cluster: <infrastructure_id>
  6.     machine.openshift.io/cluster-api-machine-role: <node_role>
  7.     machine.openshift.io/cluster-api-machine-type: <node_role>
  8.   name: <infrastructure_id>-<node_role>
  9.   namespace: openshift-machine-api
  10. spec:
  11.   replicas: <number_of_replicas>
  12.   selector:
  13.     matchLabels:
  14.       machine.openshift.io/cluster-api-cluster: <infrastructure_id>
  15.       machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<node_role>
  16.   template:
  17.     metadata:
  18.       labels:
  19.         machine.openshift.io/cluster-api-cluster: <infrastructure_id>
  20.         machine.openshift.io/cluster-api-machine-role: <node_role>
  21.         machine.openshift.io/cluster-api-machine-type: <node_role>
  22.         machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<node_role>
  23.     spec:
  24.       metadata: {}
  25.       providerSpec:
  26.         value:
  27.           apiVersion: openstackproviderconfig.openshift.io/v1alpha1
  28.           cloudName: openstack
  29.           cloudsSecret:
  30.             name: openstack-cloud-credentials
  31.             namespace: openshift-machine-api
  32.           flavor: <nova_flavor>
  33.           image: <glance_image_name_or_location>
  34.           kind: OpenstackProviderSpec
  35.           ports:
  36.             - allowedAddressPairs: (1)
  37.               - ipAddress: <API_VIP_port_IP>
  38.               - ipAddress: <ingress_VIP_port_IP>
  39.               fixedIPs:
  40.                 - subnetID: <machines_subnet_UUID> (2)
  41.               nameSuffix: nodes
  42.               networkID: <machines_network_UUID> (2)
  43.               securityGroups:
  44.                   - <compute_security_group_UUID> (3)
  45.             - networkID: <SRIOV_network_UUID>
  46.               nameSuffix: sriov
  47.               fixedIPs:
  48.                 - subnetID: <SRIOV_subnet_UUID>
  49.               tags:
  50.                 - sriov
  51.               vnicType: direct
  52.               portSecurity: False
  53.           primarySubnet: <machines_subnet_UUID>
  54.           serverMetadata:
  55.             Name: <infrastructure_ID>-<node_role>
  56.             openshiftClusterID: <infrastructure_id>
  57.           tags:
  58.           - openshiftClusterID=<infrastructure_id>
  59.           trunk: false
  60.           userDataSecret:
  61.             name: worker-user-data
1Specify allowed address pairs for the API and ingress ports.
2Specify the machines network and subnet.
3Specify the compute machines security group.

Trunking is enabled for ports that are created by entries in the networks and subnets lists. The names of ports that are created from these lists follow the pattern <machine_name>-<nameSuffix>. The nameSuffix field is required in port definitions.

You can enable trunking for each port.

Optionally, you can add tags to ports as part of their tags lists.

If your cluster uses Kuryr and the OpenStack SR-IOV network has port security disabled, the primary port for compute machines must have:

  • The value of the spec.template.spec.providerSpec.value.networks.portSecurityEnabled parameter set to false.

  • For each subnet, the value of the spec.template.spec.providerSpec.value.networks.subnets.portSecurityEnabled parameter set to false.

  • The value of spec.template.spec.providerSpec.value.securityGroups set to empty: [].

An example section of a compute machine set for a cluster on Kuryr that uses SR-IOV and has port security disabled

  1. ...
  2.           networks:
  3.             - subnets:
  4.               - uuid: <machines_subnet_UUID>
  5.                 portSecurityEnabled: false
  6.               portSecurityEnabled: false
  7.           securityGroups: []
  8. ...

In that case, you can apply the compute security group to the primary VM interface after the VM is created. For example, from a command line:

  1. $ openstack port set --enable-port-security --security-group <infrastructure_id>-<node_role> <main_port_ID>

After you deploy compute machines that are SR-IOV-capable, you must label them as such. For example, from a command line, enter:

  1. $ oc label node <NODE_NAME> feature.node.kubernetes.io/network-sriov.capable=”true”

Creating a compute machine set

In addition to the ones created by the installation program, you can create your own compute machine sets to dynamically manage the machine compute resources for specific workloads of your choice.

Prerequisites

  • Deploy an OKD cluster.

  • Install the OpenShift CLI (oc).

  • Log in to oc as a user with cluster-admin permission.

Procedure

  1. Create a new YAML file that contains the compute machine set custom resource (CR) sample and is named <file_name>.yaml.

    Ensure that you set the <clusterID> and <role> parameter values.

    1. If you are not sure which value to set for a specific field, you can check an existing compute machine set from your cluster:

      1. $ oc get machinesets -n openshift-machine-api

      Example output

      1. NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
      2. agl030519-vplxk-worker-us-east-1a   1         1         1       1           55m
      3. agl030519-vplxk-worker-us-east-1b   1         1         1       1           55m
      4. agl030519-vplxk-worker-us-east-1c   1         1         1       1           55m
      5. agl030519-vplxk-worker-us-east-1d   0         0                             55m
      6. agl030519-vplxk-worker-us-east-1e   0         0                             55m
      7. agl030519-vplxk-worker-us-east-1f   0         0                             55m

    2. Check values of a specific compute machine set:

      1. $ oc get machineset <machineset_name> -n \
      2.      openshift-machine-api -o yaml

      Example output

      1. ...
      2. template:
      3.     metadata:
      4.       labels:
      5.         machine.openshift.io/cluster-api-cluster: agl030519-vplxk (1)
      6.         machine.openshift.io/cluster-api-machine-role: worker (2)
      7.         machine.openshift.io/cluster-api-machine-type: worker
      8.         machine.openshift.io/cluster-api-machineset: agl030519-vplxk-worker-us-east-1a
      1The cluster ID.
      2A default node label.

  2. Create the new MachineSet CR:

    1. $ oc create -f <file_name>.yaml

  3. View the list of compute machine sets:

    1. $ oc get machineset -n openshift-machine-api

    Example output

    1. NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
    2. agl030519-vplxk-infra-us-east-1a    1         1         1       1           11m
    3. agl030519-vplxk-worker-us-east-1a   1         1         1       1           55m
    4. agl030519-vplxk-worker-us-east-1b   1         1         1       1           55m
    5. agl030519-vplxk-worker-us-east-1c   1         1         1       1           55m
    6. agl030519-vplxk-worker-us-east-1d   0         0                             55m
    7. agl030519-vplxk-worker-us-east-1e   0         0                             55m
    8. agl030519-vplxk-worker-us-east-1f   0         0                             55m

    When the new compute machine set is available, the DESIRED and CURRENT values match. If the compute machine set is not available, wait a few minutes and run the command again.