Configuring an Azure account - Installing on Azure | Installing

Azure account limits
Configuring a public DNS zone in Azure
Increasing Azure account limits
Required Azure roles
Creating a service principal
Supported Azure Marketplace regions
Supported Azure regions
Next steps

Before you can install OpenShift Container Platform, you must configure a Microsoft Azure account.

All Azure resources that are available through public endpoints are subject to resource name restrictions, and you cannot create resources that use certain terms. For a list of terms that Azure restricts, see Resolve reserved resource name errors in the Azure documentation.

Azure account limits

The OpenShift Container Platform cluster uses a number of Microsoft Azure components, and the default Azure subscription and service limits, quotas, and constraints affect your ability to install OpenShift Container Platform clusters.

Default limits vary by offer category types, such as Free Trial and Pay-As-You-Go, and by series, such as Dv2, F, and G. For example, the default for Enterprise Agreement subscriptions is 350 cores.

Check the limits for your subscription type and if necessary, increase quota limits for your account before you install a default cluster on Azure.

The following table summarizes the Azure components whose limits can impact your ability to install and run OpenShift Container Platform clusters.

Component Number of components required by default Default Azure limit Description

vCPU

20 per region

A default cluster requires 40 vCPUs, so you must increase the account limit.

By default, each cluster creates the following instances:

One bootstrap machine, which is removed after installation
Three control plane machines
Three compute machines

Because the bootstrap machine uses Standard_D4s_v3 machines, which use 4 vCPUs, the control plane machines use Standard_D8s_v3 virtual machines, which use 8 vCPUs, and the worker machines use Standard_D4s_v3 virtual machines, which use 4 vCPUs, a default cluster requires 40 vCPUs. The bootstrap node VM, which uses 4 vCPUs, is used only during installation.

To deploy more worker nodes, enable autoscaling, deploy large workloads, or use a different instance type, you must further increase the vCPU limit for your account to ensure that your cluster can deploy the machines that you require.

By default, the installation program distributes control plane and compute machines across all availability zones within a region. To ensure high availability for your cluster, select a region with at least three availability zones. If your region contains fewer than three availability zones, the installation program places more than one control plane machine in the available zones.

OS Disk

VM OS disk must be able to sustain a tested and recommended minimum throughput of 5000 IOPS / 200MBps for control plane machines. This throughput can be provided by having a minimum of 1 TiB Premium SSD (P30). In Azure, disk performance is directly dependent on SSD disk sizes, so to achieve the throughput supported by Standard_D8s_v3, or other similar machine types available, and the target of 5000 IOPS, at least a P30 disk is required.

Host caching must be set to ReadOnly for low read latency and high read IOPS and throughput. The reads performed from the cache, which is present either in the VM memory or in the local SSD disk, are much faster than the reads from the data disk, which is in the blob storage.

VNet

1000 per region

Each default cluster requires one Virtual Network (VNet), which contains two subnets.

Network interfaces

65,536 per region

Each default cluster requires seven network interfaces. If you create more machines or your deployed workloads create load balancers, your cluster uses more network interfaces.

Network security groups

5000

Each cluster creates network security groups for each subnet in the VNet. The default cluster creates network security groups for the control plane and for the compute node subnets:

`controlplane`	Allows the control plane machines to be reached on port 6443 from anywhere
`node`	Allows worker nodes to be reached from the internet on ports 80 and 443

Network load balancers

1000 per region

Each cluster creates the following load balancers:

`default`	Public IP address that load balances requests to ports 80 and 443 across worker machines
`internal`	Private IP address that load balances requests to ports 6443 and 22623 across control plane machines
`external`	Public IP address that load balances requests to port 6443 across control plane machines

If your applications create more Kubernetes LoadBalancer service objects, your cluster uses more load balancers.

Public IP addresses

Each of the two public load balancers uses a public IP address. The bootstrap machine also uses a public IP address so that you can SSH into the machine to troubleshoot issues during installation. The IP address for the bootstrap node is used only during installation.

Private IP addresses

The internal load balancer, each of the three control plane machines, and each of the three worker machines each use a private IP address.

Spot VM vCPUs (optional)

If you configure spot VMs, your cluster must have two spot VM vCPUs for every compute node.

20 per region

This is an optional component. To use spot VMs, you must increase the Azure default limit to at least twice the number of compute nodes in your cluster.

Using spot VMs for control plane nodes is not recommended.

Configuring a public DNS zone in Azure

To install OpenShift Container Platform, the Microsoft Azure account you use must have a dedicated public hosted DNS zone in your account. This zone must be authoritative for the domain. This service provides cluster DNS resolution and name lookup for external connections to the cluster.

Procedure

Identify your domain, or subdomain, and registrar. You can transfer an existing domain and registrar or obtain a new one through Azure or another source.

For more information about purchasing domains through Azure, see Buy a custom domain name for Azure App Service in the Azure documentation.
If you are using an existing domain and registrar, migrate its DNS to Azure. See Migrate an active DNS name to Azure App Service in the Azure documentation.
Configure DNS for your domain. Follow the steps in the Tutorial: Host your domain in Azure DNS in the Azure documentation to create a public hosted zone for your domain or subdomain, extract the new authoritative name servers, and update the registrar records for the name servers that your domain uses.

Use an appropriate root domain, such as openshiftcorp.com, or subdomain, such as clusters.openshiftcorp.com.
If you use a subdomain, follow your company’s procedures to add its delegation records to the parent domain.

Increasing Azure account limits

To increase an account limit, file a support request on the Azure portal.

You can increase only one type of quota per support request.

Procedure

From the Azure portal, click Help + support in the lower left corner.
Click New support request and then select the required values:
1. From the Issue type list, select Service and subscription limits (quotas).
2. From the Subscription list, select the subscription to modify.
3. From the Quota type list, select the quota to increase. For example, select Compute-VM (cores-vCPUs) subscription limit increases to increase the number of vCPUs, which is required to install a cluster.
4. Click Next: Solutions.
On the Problem Details page, provide the required information for your quota increase:
1. Click Provide details and provide the required details in the Quota details window.
2. In the SUPPORT METHOD and CONTACT INFO sections, provide the issue severity and your contact details.
Click Next: Review + create and then click Create.

Required Azure roles

OpenShift Container Platform needs a service principal so it can manage Microsoft Azure resources. Before you can create a service principal, your Azure account subscription must have the following roles:

User Access Administrator
Contributor

To set roles on the Azure portal, see the Manage access to Azure resources using RBAC and the Azure portal in the Azure documentation.

Creating a service principal

Because OpenShift Container Platform and its installation program create Microsoft Azure resources by using the Azure Resource Manager, you must create a service principal to represent it.

Prerequisites

Install or update the Azure CLI.
Your Azure account has the required roles for the subscription that you use.

Procedure

If your Azure account uses subscriptions, ensure that you are using the right subscription:

View the list of available accounts and record the tenantId value for the subscription you want to use for your cluster:

$ az account list --refresh

Example output

[
  {
    "cloudName": "AzureCloud",
    "id": "9bab1460-96d5-40b3-a78e-17b15e978a80",
    "isDefault": true,
    "name": "Subscription Name",
    "state": "Enabled",
    "tenantId": "6057c7e9-b3ae-489d-a54e-de3f6bf6a8ee",
    "user": {
      "name": "you@example.com",
      "type": "user"
    }
  }
]

View your active account details and confirm that the tenantId value matches the subscription you want to use:

$ az account show

Example output

{
  "environmentName": "AzureCloud",
  "id": "9bab1460-96d5-40b3-a78e-17b15e978a80",
  "isDefault": true,
  "name": "Subscription Name",
  "state": "Enabled",
  "tenantId": "6057c7e9-b3ae-489d-a54e-de3f6bf6a8ee", (1)
  "user": {
    "name": "you@example.com",
    "type": "user"
  }
}

1	Ensure that the value of the `tenantId` parameter is the correct subscription ID.

If you are not using the right subscription, change the active subscription:
```
$ az account set -s <subscription_id> (1)
```
1 Specify the subscription ID.

Verify the subscription ID update:

$ az account show

Example output

{
  "environmentName": "AzureCloud",
  "id": "33212d16-bdf6-45cb-b038-f6565b61edda",
  "isDefault": true,
  "name": "Subscription Name",
  "state": "Enabled",
  "tenantId": "8049c7e9-c3de-762d-a54e-dc3f6be6a7ee",
  "user": {
    "name": "you@example.com",
    "type": "user"
  }
}

Record the tenantId and id parameter values from the output. You need these values during the OpenShift Container Platform installation.

Create the service principal for your account:

$ az ad sp create-for-rbac --role Contributor --name <service_principal> \ (1)
  --scopes /subscriptions/<subscription_id> (2)
  --years <years> (3)

1	Specify the service principal name.
2	Specify the subscription ID.
3	Specify the number of years. By default, a service principal expires in one year. By using the `--years` option you can extend the validity of your service principal.

Example output

Creating 'Contributor' role assignment under scope '/subscriptions/<subscription_id>'
The output includes credentials that you must protect. Be sure that you do not
include these credentials in your code or check the credentials into your source
control. For more information, see https://aka.ms/azadsp-cli
{
  "appId": "ac461d78-bf4b-4387-ad16-7e32e328aec6",
  "displayName": <service_principal>",
  "password": "00000000-0000-0000-0000-000000000000",
  "tenantId": "8049c7e9-c3de-762d-a54e-dc3f6be6a7ee"
}

Record the values of the appId and password parameters from the previous output. You need these values during OpenShift Container Platform installation.

Assign the User Access Administrator role by running the following command:

$ az role assignment create --role "User Access Administrator" \
  --assignee-object-id $(az ad sp show --id <appId> --query id -o tsv) (1)

1	Specify the `appId` parameter value for your service principal.

Additional resources

For more information about CCO modes, see About the Cloud Credential Operator.

Supported Azure Marketplace regions

Installing a cluster by using the Azure Marketplace image is available to customers who purchase the offer in North America and EMEA.

While the offer must be purchased in North America or EMEA, you can deploy the cluster to any of the Azure public partitions that OpenShift Container Platform supports.

Deploying a cluster by using the Azure Marketplace image is not supported for the Azure Government regions.

Supported Azure regions

The installation program dynamically generates the list of available Microsoft Azure regions based on your subscription.

Supported Azure public regions

australiacentral (Australia Central)
australiaeast (Australia East)
australiasoutheast (Australia South East)
brazilsouth (Brazil South)
canadacentral (Canada Central)
canadaeast (Canada East)
centralindia (Central India)
centralus (Central US)
eastasia (East Asia)
eastus (East US)
eastus2 (East US 2)
francecentral (France Central)
germanywestcentral (Germany West Central)
japaneast (Japan East)
japanwest (Japan West)
koreacentral (Korea Central)
koreasouth (Korea South)
northcentralus (North Central US)
northeurope (North Europe)
norwayeast (Norway East)
qatarcentral (Qatar Central)
southafricanorth (South Africa North)
southcentralus (South Central US)
southeastasia (Southeast Asia)
southindia (South India)
switzerlandnorth (Switzerland North)
uaenorth (UAE North)
uksouth (UK South)
ukwest (UK West)
westcentralus (West Central US)
westeurope (West Europe)
westindia (West India)
westus (West US)
westus2 (West US 2)

Supported Azure Government regions

Support for the following Microsoft Azure Government (MAG) regions was added in OpenShift Container Platform version 4.6:

usgovtexas (US Gov Texas)
usgovvirginia (US Gov Virginia)

You can reference all available MAG regions in the Azure documentation. Other provided MAG regions are expected to work with OpenShift Container Platform, but have not been tested.

Next steps

Install an OpenShift Container Platform cluster on Azure. You can install a customized cluster or quickly install a cluster with default options.