Installing a cluster on Azure using ARM templates

Prerequisites
Internet access for OpenShift Container Platform
Configuring your Azure project
- Azure account limits
- Configuring a public DNS zone in Azure
- Increasing Azure account limits
- Certificate signing requests management
- Required Azure roles
- Creating a service principal
- Supported Azure regions
Requirements for a cluster with user-provisioned infrastructure
- Required machines for cluster installation
- Minimum resource requirements for cluster installation
Selecting an Azure Marketplace image
Obtaining the installation program
Generating a key pair for cluster node SSH access
Creating the installation files for Azure
- Optional: Creating a separate /var partition
- Creating the installation configuration file
- Configuring the cluster-wide proxy during installation
- Exporting common variables for ARM templates
- Creating the Kubernetes manifest and Ignition config files
Creating the Azure resource group
Uploading the RHCOS cluster image and bootstrap Ignition config file
Example for creating DNS zones
Creating a VNet in Azure
- ARM template for the VNet
Deploying the RHCOS cluster image for the Azure infrastructure
- ARM template for image storage
Networking requirements for user-provisioned infrastructure
- Network connectivity requirements
Creating networking and load balancing components in Azure
- ARM template for the network and load balancers
Creating the bootstrap machine in Azure
- ARM template for the bootstrap machine
Creating the control plane machines in Azure
- ARM template for control plane machines
Wait for bootstrap completion and remove bootstrap resources in Azure
Creating additional worker machines in Azure
- ARM template for worker machines
Installing the OpenShift CLI by downloading the binary
Logging in to the cluster by using the CLI
Approving the certificate signing requests for your machines
Adding the Ingress DNS records
Completing an Azure installation on user-provisioned infrastructure
Telemetry access for OpenShift Container Platform

In OpenShift Container Platform version 4.9, you can install a cluster on Microsoft Azure by using infrastructure that you provide.

Several Azure Resource Manager (ARM) templates are provided to assist in completing these steps or to help model your own.

The steps for performing a user-provisioned infrastructure installation are provided as an example only. Installing a cluster with infrastructure you provide requires knowledge of the cloud provider and the installation process of OpenShift Container Platform. Several ARM templates are provided to assist in completing these steps or to help model your own. You are also free to create the required resources through other methods; the templates are just an example.

Prerequisites

You reviewed details about the OpenShift Container Platform installation and update processes.
You read the documentation on selecting a cluster installation method and preparing it for users.
You configured an Azure account to host the cluster.
You downloaded the Azure CLI and installed it on your computer. See Install the Azure CLI in the Azure documentation. The documentation below was last tested using version 2.2.0 of the Azure CLI. Azure CLI commands might perform differently based on the version you use.
If you use a firewall and plan to use the Telemetry service, you configured the firewall to allow the sites that your cluster requires access to.
If the cloud identity and access management (IAM) APIs are not accessible in your environment, or if you do not want to store an administrator-level credential secret in the kube-system namespace, you can manually create and maintain IAM credentials.

Be sure to also review this site list if you are configuring a proxy.

Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.9, you require access to the internet to install your cluster.

You must have internet access to:

Access OpenShift Cluster Manager to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.
Access Quay.io to obtain the packages that are required to install your cluster.
Obtain the packages that are required to perform cluster updates.

If your cluster cannot have direct internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the required content and use it to populate a mirror registry with the installation packages. With some installation types, the environment that you install your cluster in will not require internet access. Before you update the cluster, you update the content of the mirror registry.

Configuring your Azure project

Before you can install OpenShift Container Platform, you must configure an Azure project to host it.

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 minimum throughput of 5000 IOPS / 200MBps. 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.

You can view Azure’s DNS solution by visiting this example for creating DNS zones.

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.

Certificate signing requests management

Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.

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
Owner

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)

1	Specify the service principal name.
2	Specify the subscription ID.

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 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)
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.

Requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

This section describes the requirements for deploying OpenShift Container Platform on user-provisioned infrastructure.

Required machines for cluster installation

The smallest OpenShift Container Platform clusters require the following hosts:

Table 1. Minimum required hosts
Hosts	Description
One temporary bootstrap machine	The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.
Three control plane machines	The control plane machines run the Kubernetes and OpenShift Container Platform services that form the control plane.
At least two compute machines, which are also known as worker machines.	The workloads requested by OpenShift Container Platform users run on the compute machines.

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS), Red Hat Enterprise Linux (RHEL) 7.9, or RHEL 8.4.

Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 2. Minimum resource requirements
Machine	Operating System	vCPU ^[1]	Virtual RAM	Storage	IOPS ^[2]
Bootstrap	RHCOS	4	16 GB	100 GB	300
Control plane	RHCOS	4	16 GB	100 GB	300
Compute	RHCOS, RHEL 7.9, or RHEL 8.4 ^[3]	2	8 GB	100 GB	300

One vCPU is equivalent to one physical core when simultaneous multithreading (SMT), or hyperthreading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.
OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
As with all user-provisioned installations, if you choose to use RHEL compute machines in your cluster, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Use of RHEL 7 compute machines is deprecated and planned for removal in a future release of OpenShift Container Platform 4.

You are required to use Azure virtual machines with premiumIO set to true. The machines must also have the hyperVGeneration property contain V1.

Selecting an Azure Marketplace image

If you are deploying an OpenShift Container Platform cluster using the Azure Marketplace offering, you must first obtain the Azure Marketplace image. The installation program uses this image to deploy worker nodes. 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 OpenShift Container Platform 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 OpenShift Container Platform 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 OpenShift Container Platform 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 and use them to update the 06_workers.json Azure Resource Manager (ARM) template.
Update the storageProfile.imageReference field by deleting the id parameter and adding the offer, publisher, sku, and version parameters by using the values from your offer. You can find a sample template in the "Creating additional worker machines in Azure" section.

Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on a local computer.

Prerequisites

You have a computer that runs Linux or macOS, with 500 MB of local disk space

Procedure

Access the Infrastructure Provider page on the OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
Select your infrastructure provider.

Navigate to the page for your installation type, download the installation program for your operating system, and place the file in the directory where you will store the installation configuration files.

The installation program creates several files on the computer that you use to install your cluster. You must keep the installation program and the files that the installation program creates after you finish installing the cluster. Both files are required to delete the cluster.

Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OpenShift Container Platform uninstallation procedures for your specific cloud provider.

Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:
```
$ tar -xvf openshift-install-linux.tar.gz
```
Download your installation pull secret from the Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.

Generating a key pair for cluster node SSH access

During an OpenShift Container Platform installation, you can provide an SSH public key to the installation program. The key is passed to the Red Hat Enterprise Linux CoreOS (RHCOS) nodes through their Ignition config files and is used to authenticate SSH access to the nodes. The key is added to the ~/.ssh/authorized_keys list for the core user on each node, which enables password-less authentication.

After the key is passed to the nodes, you can use the key pair to SSH in to the RHCOS nodes as the user core. To access the nodes through SSH, the private key identity must be managed by SSH for your local user.

If you want to SSH in to your cluster nodes to perform installation debugging or disaster recovery, you must provide the SSH public key during the installation process. The ./openshift-install gather command also requires the SSH public key to be in place on the cluster nodes.

Do not skip this procedure in production environments, where disaster recovery and debugging is required.

You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs.

Procedure

If you do not have an existing SSH key pair on your local machine to use for authentication onto your cluster nodes, create one. For example, on a computer that uses a Linux operating system, run the following command:

$ ssh-keygen -t ed25519 -N '' -f <path>/<file_name> (1)

1	Specify the path and file name, such as `~/.ssh/id_ed25519`, of the new SSH key. If you have an existing key pair, ensure your public key is in the your `~/.ssh` directory.

If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

View the public SSH key:
```
$ cat <path>/<file_name>.pub
```
For example, run the following to view the ~/.ssh/id_ed25519.pub public key:
```
$ cat ~/.ssh/id_ed25519.pub
```
Add the SSH private key identity to the SSH agent for your local user, if it has not already been added. SSH agent management of the key is required for password-less SSH authentication onto your cluster nodes, or if you want to use the ./openshift-install gather command.

On some distributions, default SSH private key identities such as ~/.ssh/id_rsa and ~/.ssh/id_dsa are managed automatically.
1. If the ssh-agent process is not already running for your local user, start it as a background task:
  $ eval "$(ssh-agent -s)"
  Example output
  Agent pid 31874
  If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.
Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> (1)
```
1 Specify the path and file name for your SSH private key, such as ~/.ssh/id_ed25519
Example output
```
Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
```

Next steps

When you install OpenShift Container Platform, provide the SSH public key to the installation program. If you install a cluster on infrastructure that you provision, you must provide the key to the installation program.

Creating the installation files for Azure

To install OpenShift Container Platform on Microsoft Azure using user-provisioned infrastructure, you must generate the files that the installation program needs to deploy your cluster and modify them so that the cluster creates only the machines that it will use. You generate and customize the install-config.yaml file, Kubernetes manifests, and Ignition config files. You also have the option to first set up a separate var partition during the preparation phases of installation.

Optional: Creating a separate `/var` partition

It is recommended that disk partitioning for OpenShift Container Platform be left to the installer. However, there are cases where you might want to create separate partitions in a part of the filesystem that you expect to grow.

OpenShift Container Platform supports the addition of a single partition to attach storage to either the /var partition or a subdirectory of /var. For example:

/var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system.
/var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage.
/var: Holds data that you might want to keep separate for purposes such as auditing.

Storing the contents of a /var directory separately makes it easier to grow storage for those areas as needed and reinstall OpenShift Container Platform at a later date and keep that data intact. With this method, you will not have to pull all your containers again, nor will you have to copy massive log files when you update systems.

Because /var must be in place before a fresh installation of Red Hat Enterprise Linux CoreOS (RHCOS), the following procedure sets up the separate /var partition by creating a machine config manifest that is inserted during the openshift-install preparation phases of an OpenShift Container Platform installation.

If you follow the steps to create a separate /var partition in this procedure, it is not necessary to create the Kubernetes manifest and Ignition config files again as described later in this section.

Procedure

Create a directory to hold the OpenShift Container Platform installation files:
```
$ mkdir $HOME/clusterconfig
```

Run openshift-install to create a set of files in the manifest and openshift subdirectories. Answer the system questions as you are prompted:

$ openshift-install create manifests --dir $HOME/clusterconfig

Example output

? SSH Public Key ...
INFO Credentials loaded from the "myprofile" profile in file "/home/myuser/.aws/credentials"
INFO Consuming Install Config from target directory
INFO Manifests created in: $HOME/clusterconfig/manifests and $HOME/clusterconfig/openshift

Optional: Confirm that the installation program created manifests in the clusterconfig/openshift directory:

$ ls $HOME/clusterconfig/openshift/

Example output

99_kubeadmin-password-secret.yaml
99_openshift-cluster-api_master-machines-0.yaml
99_openshift-cluster-api_master-machines-1.yaml
99_openshift-cluster-api_master-machines-2.yaml
...

Create a Butane config that configures the additional partition. For example, name the file $HOME/clusterconfig/98-var-partition.bu, change the disk device name to the name of the storage device on the worker systems, and set the storage size as appropriate. This example places the /var directory on a separate partition:

variant: openshift
version: 4.9.0
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 98-var-partition
storage:
  disks:
  - device: /dev/<device_name> (1)
    partitions:
    - label: var
      start_mib: <partition_start_offset> (2)
      size_mib: <partition_size> (3)
  filesystems:
    - device: /dev/disk/by-partlabel/var
      path: /var
      format: xfs
      mount_options: [defaults, prjquota] (4)
      with_mount_unit: true

1	The storage device name of the disk that you want to partition.
2	When adding a data partition to the boot disk, a minimum value of 25000 MiB (Mebibytes) is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of RHCOS might overwrite the beginning of the data partition.
3	The size of the data partition in mebibytes.
4	The `prjquota` mount option must be enabled for filesystems used for container storage.

When creating a separate /var partition, you cannot use different instance types for worker nodes, if the different instance types do not have the same device name.

Create a manifest from the Butane config and save it to the clusterconfig/openshift directory. For example, run the following command:
```
$ butane $HOME/clusterconfig/98-var-partition.bu -o $HOME/clusterconfig/openshift/98-var-partition.yaml
```

Run openshift-install again to create Ignition configs from a set of files in the manifest and openshift subdirectories:

$ openshift-install create ignition-configs --dir $HOME/clusterconfig
$ ls $HOME/clusterconfig/
auth  bootstrap.ign  master.ign  metadata.json  worker.ign

Now you can use the Ignition config files as input to the installation procedures to install Red Hat Enterprise Linux CoreOS (RHCOS) systems.

Creating the installation configuration file

You can customize the OpenShift Container Platform cluster you install on Microsoft Azure.

Prerequisites

Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.
Obtain service principal permissions at the subscription level.

Procedure

Create the install-config.yaml file.

Change to the directory that contains the installation program and run the following command:

$ ./openshift-install create install-config --dir <installation_directory> (1)

1	For `<installation_directory>`, specify the directory name to store the files that the installation program creates.

Specify an empty directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.

At the prompts, provide the configuration details for your cloud:

Optional: Select an SSH key to use to access your cluster machines.

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.
Select azure as the platform to target.
If you do not have a Microsoft Azure profile stored on your computer, specify the following Azure parameter values for your subscription and service principal:
- azure subscription id: The subscription ID to use for the cluster. Specify the id value in your account output.
- azure tenant id: The tenant ID. Specify the tenantId value in your account output.
- azure service principal client id: The value of the appId parameter for the service principal.
- azure service principal client secret: The value of the password parameter for the service principal.
Select the region to deploy the cluster to.
Select the base domain to deploy the cluster to. The base domain corresponds to the Azure DNS Zone that you created for your cluster.

Enter a descriptive name for your cluster.

Paste the pull secret from the Red Hat OpenShift Cluster Manager.

Optional: If you do not want the cluster to provision compute machines, empty the compute pool by editing the resulting install-config.yaml file to set replicas to 0 for the compute pool:
```
compute:
- hyperthreading: Enabled
  name: worker
  platform: {}
  replicas: 0 (1)
```
1 Set to 0.

Modify the install-config.yaml file. You can find more information about the available parameters in the "Installation configuration parameters" section.
Back up the install-config.yaml file so that you can use it to install multiple clusters.

The install-config.yaml file is consumed during the installation process. If you want to reuse the file, you must back it up now.

Configuring the cluster-wide proxy during installation

Production environments can deny direct access to the internet and instead have an HTTP or HTTPS proxy available. You can configure a new OpenShift Container Platform cluster to use a proxy by configuring the proxy settings in the install-config.yaml file.

Prerequisites

You have an existing install-config.yaml file.

You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.

The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.

For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

Edit your install-config.yaml file and add the proxy settings. For example:

apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> (1)
  httpsProxy: https://<username>:<pswd>@<ip>:<port> (2)
  noProxy: example.com (3)
additionalTrustBundle: | (4)
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...

1	A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be `http`.
2	A proxy URL to use for creating HTTPS connections outside the cluster.
3	A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with `.` to match subdomains only. For example, `.y.com` matches `x.y.com`, but not `y.com`. Use `*` to bypass the proxy for all destinations.
4	If provided, the installation program generates a config map that is named `user-ca-bundle` in the `openshift-config` namespace to hold the additional CA certificates. If you provide `additionalTrustBundle` and at least one proxy setting, the `Proxy` object is configured to reference the `user-ca-bundle` config map in the `trustedCA` field. The Cluster Network Operator then creates a `trusted-ca-bundle` config map that merges the contents specified for the `trustedCA` parameter with the RHCOS trust bundle. The `additionalTrustBundle` field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.

The installation program does not support the proxy readinessEndpoints field.

Save the file and reference it when installing OpenShift Container Platform.

The installation program creates a cluster-wide proxy that is named cluster that uses the proxy settings in the provided install-config.yaml file. If no proxy settings are provided, a cluster Proxy object is still created, but it will have a nil spec.

Only the Proxy object named cluster is supported, and no additional proxies can be created.

Exporting common variables for ARM templates

You must export a common set of variables that are used with the provided Azure Resource Manager (ARM) templates used to assist in completing a user-provided infrastructure install on Microsoft Azure.

Specific ARM templates can also require additional exported variables, which are detailed in their related procedures.

Prerequisites

Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.

Procedure

Export common variables found in the install-config.yaml to be used by the provided ARM templates:

$ export CLUSTER_NAME=<cluster_name>(1)
$ export AZURE_REGION=<azure_region>(2)
$ export SSH_KEY=<ssh_key>(3)
$ export BASE_DOMAIN=<base_domain>(4)
$ export BASE_DOMAIN_RESOURCE_GROUP=<base_domain_resource_group>(5)

1	The value of the `.metadata.name` attribute from the `install-config.yaml` file.
2	The region to deploy the cluster into, for example `centralus`. This is the value of the `.platform.azure.region` attribute from the `install-config.yaml` file.
3	The SSH RSA public key file as a string. You must enclose the SSH key in quotes since it contains spaces. This is the value of the `.sshKey` attribute from the `install-config.yaml` file.
4	The base domain to deploy the cluster to. The base domain corresponds to the public DNS zone that you created for your cluster. This is the value of the `.baseDomain` attribute from the `install-config.yaml` file.
5	The resource group where the public DNS zone exists. This is the value of the `.platform.azure.baseDomainResourceGroupName` attribute from the `install-config.yaml` file.

For example:

$ export CLUSTER_NAME=test-cluster
$ export AZURE_REGION=centralus
$ export SSH_KEY="ssh-rsa xxx/xxx/xxx= user@email.com"
$ export BASE_DOMAIN=example.com
$ export BASE_DOMAIN_RESOURCE_GROUP=ocp-cluster

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig (1)
```
1 For <installation_directory>, specify the path to the directory that you stored the installation files in.

Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to configure the machines.

The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to configure the cluster machines.

The Ignition config files that the OpenShift Container Platform installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.

Prerequisites

You obtained the OpenShift Container Platform installation program.
You created the install-config.yaml installation configuration file.

Procedure

Change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster:
```
$ ./openshift-install create manifests --dir <installation_directory> (1)
```
1 For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
Remove the Kubernetes manifest files that define the control plane machines:
```
$ rm -f <installation_directory>/openshift/99_openshift-cluster-api_master-machines-*.yaml
```
By removing these files, you prevent the cluster from automatically generating control plane machines.
Remove the Kubernetes manifest files that define the worker machines:
```
$ rm -f <installation_directory>/openshift/99_openshift-cluster-api_worker-machineset-*.yaml
```
Because you create and manage the worker machines yourself, you do not need to initialize these machines.
Check that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file is set to false. This setting prevents pods from being scheduled on the control plane machines:
1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
2. Locate the mastersSchedulable parameter and ensure that it is set to false.
3. Save and exit the file.
Optional: If you do not want the Ingress Operator to create DNS records on your behalf, remove the privateZone and publicZone sections from the <installation_directory>/manifests/cluster-dns-02-config.yml DNS configuration file:
```
apiVersion: config.openshift.io/v1
kind: DNS
metadata:
  creationTimestamp: null
  name: cluster
spec:
  baseDomain: example.openshift.com
  privateZone: (1)
    id: mycluster-100419-private-zone
  publicZone: (1)
    id: example.openshift.com
status: {}
```
1 Remove this section completely.

If you do so, you must add ingress DNS records manually in a later step.

When configuring Azure on user-provisioned infrastructure, you must export some common variables defined in the manifest files to use later in the Azure Resource Manager (ARM) templates:

Export the infrastructure ID by using the following command:

$ export INFRA_ID=<infra_id> (1)

1 The OpenShift Container Platform cluster has been assigned an identifier (INFRA_ID) in the form of <cluster_name>-<random_string>. This will be used as the base name for most resources created using the provided ARM templates. This is the value of the .status.infrastructureName attribute from the manifests/cluster-infrastructure-02-config.yml file.

Export the resource group by using the following command:

$ export RESOURCE_GROUP=<resource_group> (1)

1 All resources created in this Azure deployment exists as part of a resource group. The resource group name is also based on the INFRA_ID, in the form of <cluster_name>-<random_string>-rg. This is the value of the .status.platformStatus.azure.resourceGroupName attribute from the manifests/cluster-infrastructure-02-config.yml file.

To create the Ignition configuration files, run the following command from the directory that contains the installation program:
```
$ ./openshift-install create ignition-configs --dir <installation_directory> (1)
```
1 For <installation_directory>, specify the same installation directory.

Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory. The kubeadmin-password and kubeconfig files are created in the ./<installation_directory>/auth directory:
```
.
├── auth
│   ├── kubeadmin-password
│   └── kubeconfig
├── bootstrap.ign
├── master.ign
├── metadata.json
└── worker.ign
```

Creating the Azure resource group

You must create a Microsoft Azure resource group and an identity for that resource group. These are both used during the installation of your OpenShift Container Platform cluster on Azure.

Prerequisites

Configure an Azure account.
Generate the Ignition config files for your cluster.

Procedure

Create the resource group in a supported Azure region:

$ az group create --name ${RESOURCE_GROUP} --location ${AZURE_REGION}

Create an Azure identity for the resource group:
```
$ az identity create -g ${RESOURCE_GROUP} -n ${INFRA_ID}-identity
```
This is used to grant the required access to Operators in your cluster. For example, this allows the Ingress Operator to create a public IP and its load balancer. You must assign the Azure identity to a role.

Grant the Contributor role to the Azure identity:

Export the following variables required by the Azure role assignment:

$ export PRINCIPAL_ID=`az identity show -g ${RESOURCE_GROUP} -n ${INFRA_ID}-identity --query principalId --out tsv`

$ export RESOURCE_GROUP_ID=`az group show -g ${RESOURCE_GROUP} --query id --out tsv`

Assign the Contributor role to the identity:

$ az role assignment create --assignee "${PRINCIPAL_ID}" --role 'Contributor' --scope "${RESOURCE_GROUP_ID}"

Uploading the RHCOS cluster image and bootstrap Ignition config file

The Azure client does not support deployments based on files existing locally; therefore, you must copy and store the RHCOS virtual hard disk (VHD) cluster image and bootstrap Ignition config file in a storage container so they are accessible during deployment.

Prerequisites

Configure an Azure account.
Generate the Ignition config files for your cluster.

Procedure

Create an Azure storage account to store the VHD cluster image:

$ az storage account create -g ${RESOURCE_GROUP} --location ${AZURE_REGION} --name ${CLUSTER_NAME}sa --kind Storage --sku Standard_LRS

The Azure storage account name must be between 3 and 24 characters in length and use numbers and lower-case letters only. If your CLUSTER_NAME variable does not follow these restrictions, you must manually define the Azure storage account name. For more information on Azure storage account name restrictions, see Resolve errors for storage account names in the Azure documentation.

Export the storage account key as an environment variable:

$ export ACCOUNT_KEY=`az storage account keys list -g ${RESOURCE_GROUP} --account-name ${CLUSTER_NAME}sa --query "[0].value" -o tsv`

Choose the RHCOS version to use and export the URL of its VHD to an environment variable:

$ export VHD_URL=`curl -s https://raw.githubusercontent.com/openshift/installer/release-4.9/data/data/rhcos.json | jq -r .azure.url`

The RHCOS images might not change with every release of OpenShift Container Platform. You must specify an image with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image version that matches your OpenShift Container Platform version if it is available.

Create the storage container for the VHD:

$ az storage container create --name vhd --account-name ${CLUSTER_NAME}sa --account-key ${ACCOUNT_KEY}

Copy the chosen VHD to a blob:

$ az storage blob copy start --account-name ${CLUSTER_NAME}sa --account-key ${ACCOUNT_KEY} --destination-blob "rhcos.vhd" --destination-container vhd --source-uri "${VHD_URL}"

Create a blob storage container and upload the generated bootstrap.ign file:

$ az storage container create --name files --account-name ${CLUSTER_NAME}sa --account-key ${ACCOUNT_KEY} --public-access blob

$ az storage blob upload --account-name ${CLUSTER_NAME}sa --account-key ${ACCOUNT_KEY} -c "files" -f "<installation_directory>/bootstrap.ign" -n "bootstrap.ign"

Example for creating DNS zones

DNS records are required for clusters that use user-provisioned infrastructure. You should choose the DNS strategy that fits your scenario.

For this example, Azure’s DNS solution is used, so you will create a new public DNS zone for external (internet) visibility and a private DNS zone for internal cluster resolution.

The public DNS zone is not required to exist in the same resource group as the cluster deployment and might already exist in your organization for the desired base domain. If that is the case, you can skip creating the public DNS zone; be sure the installation config you generated earlier reflects that scenario.

Prerequisites

Configure an Azure account.
Generate the Ignition config files for your cluster.

Procedure

Create the new public DNS zone in the resource group exported in the BASE_DOMAIN_RESOURCE_GROUP environment variable:
```
$ az network dns zone create -g ${BASE_DOMAIN_RESOURCE_GROUP} -n ${CLUSTER_NAME}.${BASE_DOMAIN}
```
You can skip this step if you are using a public DNS zone that already exists.

Create the private DNS zone in the same resource group as the rest of this deployment:

$ az network private-dns zone create -g ${RESOURCE_GROUP} -n ${CLUSTER_NAME}.${BASE_DOMAIN}

You can learn more about configuring a public DNS zone in Azure by visiting that section.

Creating a VNet in Azure

You must create a virtual network (VNet) in Microsoft Azure for your OpenShift Container Platform cluster to use. You can customize the VNet to meet your requirements. One way to create the VNet is to modify the provided Azure Resource Manager (ARM) template.

If you do not use the provided ARM template to create your Azure infrastructure, you must review the provided information and manually create the infrastructure. If your cluster does not initialize correctly, you might have to contact Red Hat support with your installation logs.

Prerequisites

Configure an Azure account.
Generate the Ignition config files for your cluster.

Procedure

Copy the template from the ARM template for the VNet section of this topic and save it as 01_vnet.json in your cluster’s installation directory. This template describes the VNet that your cluster requires.

Create the deployment by using the az CLI:

$ az deployment group create -g ${RESOURCE_GROUP} \
  --template-file "<installation_directory>/01_vnet.json" \
  --parameters baseName="${INFRA_ID}"(1)

1	The base name to be used in resource names; this is usually the cluster’s infrastructure ID.

Link the VNet template to the private DNS zone:

$ az network private-dns link vnet create -g ${RESOURCE_GROUP} -z ${CLUSTER_NAME}.${BASE_DOMAIN} -n ${INFRA_ID}-network-link -v "${INFRA_ID}-vnet" -e false

ARM template for the VNet

You can use the following Azure Resource Manager (ARM) template to deploy the VNet that you need for your OpenShift Container Platform cluster:

01_vnet.json ARM template

{
  "$schema" : "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
  "contentVersion" : "1.0.0.0",
  "parameters" : {
    "baseName" : {
      "type" : "string",
      "minLength" : 1,
      "metadata" : {
        "description" : "Base name to be used in resource names (usually the cluster's Infra ID)"
      }
    }
  },
  "variables" : {
    "location" : "[resourceGroup().location]",
    "virtualNetworkName" : "[concat(parameters('baseName'), '-vnet')]",
    "addressPrefix" : "10.0.0.0/16",
    "masterSubnetName" : "[concat(parameters('baseName'), '-master-subnet')]",
    "masterSubnetPrefix" : "10.0.0.0/24",
    "nodeSubnetName" : "[concat(parameters('baseName'), '-worker-subnet')]",
    "nodeSubnetPrefix" : "10.0.1.0/24",
    "clusterNsgName" : "[concat(parameters('baseName'), '-nsg')]"
  },
  "resources" : [
    {
      "apiVersion" : "2018-12-01",
      "type" : "Microsoft.Network/virtualNetworks",
      "name" : "[variables('virtualNetworkName')]",
      "location" : "[variables('location')]",
      "dependsOn" : [
        "[concat('Microsoft.Network/networkSecurityGroups/', variables('clusterNsgName'))]"
      ],
      "properties" : {
        "addressSpace" : {
          "addressPrefixes" : [
            "[variables('addressPrefix')]"
          ]
        },
        "subnets" : [
          {
            "name" : "[variables('masterSubnetName')]",
            "properties" : {
              "addressPrefix" : "[variables('masterSubnetPrefix')]",
              "serviceEndpoints": [],
              "networkSecurityGroup" : {
                "id" : "[resourceId('Microsoft.Network/networkSecurityGroups', variables('clusterNsgName'))]"
              }
            }
          },
          {
            "name" : "[va

Prerequisites

Internet access for OpenShift Container Platform

Configuring your Azure project

Azure account limits

Configuring a public DNS zone in Azure

Increasing Azure account limits

Certificate signing requests management

Required Azure roles

Creating a service principal

Supported Azure regions

Supported Azure public regions

Supported Azure Government regions

Requirements for a cluster with user-provisioned infrastructure

Required machines for cluster installation

Minimum resource requirements for cluster installation

Selecting an Azure Marketplace image

Obtaining the installation program

Generating a key pair for cluster node SSH access

Creating the installation files for Azure

Optional: Creating a separate /var partition

Creating the installation configuration file

Configuring the cluster-wide proxy during installation

Exporting common variables for ARM templates

Creating the Kubernetes manifest and Ignition config files

Creating the Azure resource group

Uploading the RHCOS cluster image and bootstrap Ignition config file

Example for creating DNS zones

Creating a VNet in Azure

ARM template for the VNet

Optional: Creating a separate `/var` partition