Creating a machine set on Azure - Managing compute machines with the Machine API | Machine management

Sample YAML for a machine set custom resource on Azure
Creating a machine set
Selecting an Azure Marketplace image
Machine sets that deploy machines as Spot VMs
Creating Spot VMs by using machine sets
Machine sets that deploy machines on Ephemeral OS disks
Creating machines on Ephemeral OS disks by using machine sets
Enabling customer-managed encryption keys for a machine set
Accelerated Networking for Microsoft Azure VMs
- Limitations
Enabling Accelerated Networking on an existing Microsoft Azure cluster

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

You can use the advanced machine management and scaling capabilities only in clusters where the Machine API is operational. Clusters with user-provisioned infrastructure require additional validation and configuration to use the Machine API.

Clusters with the infrastructure platform type none cannot use the Machine API. This limitation applies even if the compute machines that are attached to the cluster are installed on a platform that supports the feature. This parameter cannot be changed after installation.

To view the platform type for your cluster, run the following command:

$ oc get infrastructure cluster -o jsonpath='{.status.platform}'

Sample YAML for a machine set custom resource on Azure

This sample YAML defines a machine set that runs in the 1 Microsoft Azure zone in a region 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.

apiVersion: machine.openshift.io/v1beta1
kind: MachineSet
metadata:
  labels:
    machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
    machine.openshift.io/cluster-api-machine-role: <role> (2)
    machine.openshift.io/cluster-api-machine-type: <role> (2)
  name: <infrastructure_id>-<role>-<region> (3)
  namespace: openshift-machine-api
spec:
  replicas: 1
  selector:
    matchLabels:
      machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
      machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>-<region> (3)
  template:
    metadata:
      creationTimestamp: null
      labels:
        machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
        machine.openshift.io/cluster-api-machine-role: <role> (2)
        machine.openshift.io/cluster-api-machine-type: <role> (2)
        machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>-<region> (3)
    spec:
      metadata:
        creationTimestamp: null
        labels:
          machine.openshift.io/cluster-api-machineset: <machineset_name> (4)
          node-role.kubernetes.io/<role>: "" (2)
      providerSpec:
        value:
          apiVersion: azureproviderconfig.openshift.io/v1beta1
          credentialsSecret:
            name: azure-cloud-credentials
            namespace: openshift-machine-api
          image: (5)
            offer: ""
            publisher: ""
            resourceID: /resourceGroups/<infrastructure_id>-rg/providers/Microsoft.Compute/images/<infrastructure_id> (6)
            sku: ""
            version: ""
          internalLoadBalancer: ""
          kind: AzureMachineProviderSpec
          location: <region> (7)
          managedIdentity: <infrastructure_id>-identity (1)
          metadata:
            creationTimestamp: null
          natRule: null
          networkResourceGroup: ""
          osDisk:
            diskSizeGB: 128
            managedDisk:
              storageAccountType: Premium_LRS
            osType: Linux
          publicIP: false
          publicLoadBalancer: ""
          resourceGroup: <infrastructure_id>-rg (1)
          sshPrivateKey: ""
          sshPublicKey: ""
          tags:
            - name: <custom_tag_name> (9)
              value: <custom_tag_value> (9)
          subnet: <infrastructure_id>-<role>-subnet  (1) (2)
          userDataSecret:
            name: worker-user-data (2)
          vmSize: Standard_D4s_v3
          vnet: <infrastructure_id>-vnet (1)
          zone: "1" (8)

1	Specify 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: `$ oc get -o jsonpath='{.status.infrastructureName}{"\n"}' infrastructure cluster` You can obtain the subnet by running the following command: `$ oc -n openshift-machine-api \ -o jsonpath='{.spec.template.spec.providerSpec.value.subnet}{"\n"}' \ get machineset/<infrastructure_id>-worker-centralus1` You can obtain the vnet by running the following command: `$ oc -n openshift-machine-api \ -o jsonpath='{.spec.template.spec.providerSpec.value.vnet}{"\n"}' \ get machineset/<infrastructure_id>-worker-centralus1`
2	Specify the node label to add.
3	Specify the infrastructure ID, node label, and region.
4	Optional: Specify the machine set name to enable the use of availability sets. This setting only applies to new compute machines.
5	Specify the image details for your machine set. If you want to use an Azure Marketplace image, see "Selecting an Azure Marketplace image".
6	Specify an image that is compatible with your instance type. The Hyper-V generation V2 images created by the installation program have a `-gen2` suffix, while V1 images have the same name without the suffix.
7	Specify the region to place machines on.
8	Specify the zone within your region to place machines on. Be sure that your region supports the zone that you specify.
9	Optional: Specify custom tags in your machine set. Provide the tag name in `<custom_tag_name>` field and the corresponding tag value in `<custom_tag_value>` field.

Creating a machine set

In addition to the compute machine sets created by the installation program, you can create your own 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

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

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

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

To list the compute machine sets in your cluster, run the following command:

$ oc get machinesets -n openshift-machine-api

Example output

NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
agl030519-vplxk-worker-us-east-1a   1         1         1       1           55m
agl030519-vplxk-worker-us-east-1b   1         1         1       1           55m
agl030519-vplxk-worker-us-east-1c   1         1         1       1           55m
agl030519-vplxk-worker-us-east-1d   0         0                             55m
agl030519-vplxk-worker-us-east-1e   0         0                             55m
agl030519-vplxk-worker-us-east-1f   0         0                             55m

To view values of a specific compute machine set custom resource (CR), run the following command:

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

Example output

apiVersion: machine.openshift.io/v1beta1
kind: MachineSet
metadata:
  labels:
    machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
  name: <infrastructure_id>-<role> (2)
  namespace: openshift-machine-api
spec:
  replicas: 1
  selector:
    matchLabels:
      machine.openshift.io/cluster-api-cluster: <infrastructure_id>
      machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>
  template:
    metadata:
      labels:
        machine.openshift.io/cluster-api-cluster: <infrastructure_id>
        machine.openshift.io/cluster-api-machine-role: <role>
        machine.openshift.io/cluster-api-machine-type: <role>
        machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>
    spec:
      providerSpec: (3)
        ...

1 The cluster infrastructure ID.

A default node label.

For clusters that have user-provisioned infrastructure, a compute machine set can only create worker and infra type machines.

3 The values in the <providerSpec> section of the compute machine set CR are platform-specific. For more information about <providerSpec> parameters in the CR, see the sample compute machine set CR configuration for your provider.

Create a MachineSet CR by running the following command:
```
$ oc create -f <file_name>.yaml
```

Verification

View the list of compute machine sets by running the following command:

$ oc get machineset -n openshift-machine-api

Example output

NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
agl030519-vplxk-infra-us-east-1a    1         1         1       1           11m
agl030519-vplxk-worker-us-east-1a   1         1         1       1           55m
agl030519-vplxk-worker-us-east-1b   1         1         1       1           55m
agl030519-vplxk-worker-us-east-1c   1         1         1       1           55m
agl030519-vplxk-worker-us-east-1d   0         0                             55m
agl030519-vplxk-worker-us-east-1e   0         0                             55m
agl030519-vplxk-worker-us-east-1f   0         0                             55m

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

Selecting an Azure Marketplace image

You can create a machine set running on Azure that deploys machines that use the Azure Marketplace offering. To use this offering, you must first obtain the Azure Marketplace image. When obtaining your image, consider the following:

While the images are the same, the Azure Marketplace publisher is different depending on your region. If you are located in North America, specify redhat as the publisher. If you are located in EMEA, specify redhat-limited as the publisher.
The offer includes a rh-ocp-worker SKU and a rh-ocp-worker-gen1 SKU. The rh-ocp-worker SKU represents a Hyper-V generation version 2 VM image. The default instance types used in OKD are version 2 compatible. If you are going to use an instance type that is only version 1 compatible, use the image associated with the rh-ocp-worker-gen1 SKU. The rh-ocp-worker-gen1 SKU represents a Hyper-V version 1 VM image.

Prerequisites

You have installed the Azure CLI client (az).
Your Azure account is entitled for the offer and you have logged into this account with the Azure CLI client.

Procedure

Display all of the available OKD images by running one of the following commands:

North America:

$  az vm image list --all --offer rh-ocp-worker --publisher redhat -o table

Example output

Offer          Publisher       Sku                 Urn                                                             Version
-------------  --------------  ------------------  --------------------------------------------------------------  --------------
rh-ocp-worker  RedHat          rh-ocp-worker       RedHat:rh-ocp-worker:rh-ocpworker:4.8.2021122100               4.8.2021122100
rh-ocp-worker  RedHat          rh-ocp-worker-gen1  RedHat:rh-ocp-worker:rh-ocp-worker-gen1:4.8.2021122100         4.8.2021122100

EMEA:

$  az vm image list --all --offer rh-ocp-worker --publisher redhat-limited -o table

Example output

Offer          Publisher       Sku                 Urn                                                             Version
-------------  --------------  ------------------  --------------------------------------------------------------  --------------
rh-ocp-worker  redhat-limited  rh-ocp-worker       redhat-limited:rh-ocp-worker:rh-ocp-worker:4.8.2021122100       4.8.2021122100
rh-ocp-worker  redhat-limited  rh-ocp-worker-gen1  redhat-limited:rh-ocp-worker:rh-ocp-worker-gen1:4.8.2021122100  4.8.2021122100

Regardless of the version of OKD you are installing, the correct version of the Azure Marketplace image to use is 4.8.x. If required, as part of the installation process, your VMs are automatically upgraded.

Inspect the image for your offer by running one of the following commands:

North America:

$ az vm image show --urn redhat:rh-ocp-worker:rh-ocp-worker:<version>

EMEA:

$ az vm image show --urn redhat-limited:rh-ocp-worker:rh-ocp-worker:<version>

Review the terms of the offer by running one of the following commands:

North America:

$ az vm image terms show --urn redhat:rh-ocp-worker:rh-ocp-worker:<version>

EMEA:

$ az vm image terms show --urn redhat-limited:rh-ocp-worker:rh-ocp-worker:<version>

Accept the terms of the offering by running one of the following commands:

North America:

$ az vm image terms accept --urn redhat:rh-ocp-worker:rh-ocp-worker:<version>

EMEA:

$ az vm image terms accept --urn redhat-limited:rh-ocp-worker:rh-ocp-worker:<version>

Record the image details of your offer, specifically the values for publisher, offer, sku, and version.

Add the following parameters to the providerSpec section of your machine set YAML file using the image details for your offer:

Sample providerSpec image values for Azure Marketplace compute machines

providerSpec:
  value:
    image:
      offer: rh-ocp-worker
      publisher: redhat
      resourceID: ""
      sku: rh-ocp-worker
      type: MarketplaceWithPlan
      version: 4.8.2021122100

Machine sets that deploy machines as Spot VMs

You can save on costs by creating a machine set running on Azure that deploys machines as non-guaranteed Spot VMs. Spot VMs utilize unused Azure capacity and are less expensive than standard VMs. You can use Spot VMs for workloads that can tolerate interruptions, such as batch or stateless, horizontally scalable workloads.

Azure can terminate a Spot VM at any time. Azure gives a 30-second warning to the user when an interruption occurs. OKD begins to remove the workloads from the affected instances when Azure issues the termination warning.

Interruptions can occur when using Spot VMs for the following reasons:

The instance price exceeds your maximum price
The supply of Spot VMs decreases
Azure needs capacity back

When Azure terminates an instance, a termination handler running on the Spot VM node deletes the machine resource. To satisfy the machine set replicas quantity, the machine set creates a machine that requests a Spot VM.

Creating Spot VMs by using machine sets

You can launch a Spot VM on Azure by adding spotVMOptions to your machine set YAML file.

Procedure

Add the following line under the providerSpec field:
```
providerSpec:
  value:
    spotVMOptions: {}
```
You can optionally set the spotVMOptions.maxPrice field to limit the cost of the Spot VM. For example you can set maxPrice: '0.98765'. If the maxPrice is set, this value is used as the hourly maximum spot price. If it is not set, the maximum price defaults to -1 and charges up to the standard VM price.

Azure caps Spot VM prices at the standard price. Azure will not evict an instance due to pricing if the instance is set with the default maxPrice. However, an instance can still be evicted due to capacity restrictions.

It is strongly recommended to use the default standard VM price as the maxPrice value and to not set the maximum price for Spot VMs.

Machine sets that deploy machines on Ephemeral OS disks

You can create a machine set running on Azure that deploys machines on Ephemeral OS disks. Ephemeral OS disks use local VM capacity rather than remote Azure Storage. This configuration therefore incurs no additional cost and provides lower latency for reading, writing, and reimaging.

Additional resources

For more information, see the Microsoft Azure documentation about Ephemeral OS disks for Azure VMs.

Creating machines on Ephemeral OS disks by using machine sets

You can launch machines on Ephemeral OS disks on Azure by editing your machine set YAML file.

Prerequisites

Have an existing Microsoft Azure cluster.

Procedure

Edit the custom resource (CR) by running the following command:
```
$ oc edit machineset <machine-set-name>
```
where <machine-set-name> is the machine set that you want to provision machines on Ephemeral OS disks.
Add the following to the providerSpec field:
```
providerSpec:
  value:
    ...
    osDisk:
       ...
       diskSettings: (1)
         ephemeralStorageLocation: Local (1)
       cachingType: ReadOnly (1)
       managedDisk:
         storageAccountType: Standard_LRS (2)
       ...
```
1 These lines enable the use of Ephemeral OS disks.

2 Ephemeral OS disks are only supported for VMs or scale set instances that use the Standard LRS storage account type.

The implementation of Ephemeral OS disk support in OKD only supports the CacheDisk placement type. Do not change the placement configuration setting.
Create a machine set using the updated configuration:
```
$ oc create -f <machine-set-config>.yaml
```

Verification

On the Microsoft Azure portal, review the Overview page for a machine deployed by the machine set, and verify that the Ephemeral OS disk field is set to OS cache placement.

Enabling customer-managed encryption keys for a machine set

You can supply an encryption key to Azure to encrypt data on managed disks at rest. You can enable server-side encryption with customer-managed keys by using the Machine API.

An Azure Key Vault, a disk encryption set, and an encryption key are required to use a customer-managed key. The disk encryption set must preside in a resource group where the Cloud Credential Operator (CCO) has granted permissions. If not, an additional reader role is required to be granted on the disk encryption set.

Prerequisites

Procedure

Configure the disk encryption set under the providerSpec field in your machine set YAML file. For example:

...
providerSpec:
  value:
    ...
    osDisk:
      diskSizeGB: 128
      managedDisk:
        diskEncryptionSet:
          id: /subscriptions/<subscription_id>/resourceGroups/<resource_group_name>/providers/Microsoft.Compute/diskEncryptionSets/<disk_encryption_set_name>
        storageAccountType: Premium_LRS
...

Additional resources

You can learn more about customer-managed keys in the Azure documentation.

Accelerated Networking for Microsoft Azure VMs

Accelerated Networking uses single root I/O virtualization (SR-IOV) to provide Microsoft Azure VMs with a more direct path to the switch. This enhances network performance. This feature can be enabled during or after installation.

Limitations

Consider the following limitations when deciding whether to use Accelerated Networking:

Accelerated Networking is only supported on clusters where the Machine API is operational.
Although the minimum requirement for an Azure worker node is two vCPUs, Accelerated Networking requires an Azure VM size that includes at least four vCPUs. To satisfy this requirement, you can change the value of vmSize in your machine set. For information about Azure VM sizes, see Microsoft Azure documentation.
When this feature is enabled on an existing Azure cluster, only newly provisioned nodes are affected. Currently running nodes are not reconciled. To enable the feature on all nodes, you must replace each existing machine. This can be done for each machine individually, or by scaling the replicas down to zero, and then scaling back up to your desired number of replicas.

Additional resources

For information about enabling Accelerated Networking during installation, see Enabling Accelerated Networking during installation.

Enabling Accelerated Networking on an existing Microsoft Azure cluster

You can enable Accelerated Networking on Azure by adding acceleratedNetworking to your machine set YAML file.

Prerequisites

Have an existing Microsoft Azure cluster where the Machine API is operational.

Procedure

List the machine sets in your cluster by running the following command:

$ oc get machinesets -n openshift-machine-api

The machine sets are listed in the form of <cluster-id>-worker-<region>.

Example output

NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
jmywbfb-8zqpx-worker-centralus1     1         1         1       1           15m
jmywbfb-8zqpx-worker-centralus2     1         1         1       1           15m
jmywbfb-8zqpx-worker-centralus3     1         1         1       1           15m

For each machine set:
1. Edit the custom resource (CR) by running the following command:
  $ oc edit machineset <machine-set-name>
2. Add the following to the providerSpec field:
  providerSpec: value: ... acceleratedNetworking: true (1) ... vmSize: <azure-vm-size> (2) ...
  1 This line enables Accelerated Networking.
  
  2 Specify an Azure VM size that includes at least four vCPUs. For information about VM sizes, see Microsoft Azure documentation.
To enable the feature on currently running nodes, you must replace each existing machine. This can be done for each machine individually, or by scaling the replicas down to zero, and then scaling back up to your desired number of replicas.

Verification

On the Microsoft Azure portal, review the Networking settings page for a machine provisioned by the machine set, and verify that the Accelerated networking field is set to Enabled.

Additional resources

For more details about scaling a machine set, see Manually scaling a machine set.

1	These lines enable the use of Ephemeral OS disks.
2	Ephemeral OS disks are only supported for VMs or scale set instances that use the Standard LRS storage account type.

1	This line enables Accelerated Networking.
2	Specify an Azure VM size that includes at least four vCPUs. For information about VM sizes, see Microsoft Azure documentation.