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Installing a cluster on VMC
- Setting up VMC for vSphere
- vSphere prerequisites
- VMware vSphere infrastructure requirements
- Network connectivity requirements
- vCenter requirements
- Generating a key pair for cluster node SSH access
- Obtaining the installation program
- Adding vCenter root CA certificates to your system trust
- Deploying the cluster
- Installing the OpenShift CLI by downloading the binary
- Logging in to the cluster by using the CLI
- Creating registry storage
- Backing up VMware vSphere volumes
- Steal clock accounting
- Next steps
In OKD version 4.9, you can install a cluster on VMware vSphere by deploying it to VMware Cloud (VMC) on AWS.
Once you have configured your VMC environment for OKD deployment, you use the OKD installation program from the bastion management host, co-located in the VMC environment. The installation program and control plane automates the process of deploying and managing the resources needed for the OKD cluster.
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OKD supports deploying a cluster to a single VMware vCenter only. Deploying a cluster with machines/machine sets on multiple vCenters is not supported. |
Setting up VMC for vSphere
You can install OKD on VMware Cloud (VMC) on AWS hosted vSphere clusters to enable applications to be deployed and managed both on-premise and off-premise, across the hybrid cloud.
You must configure several options in your VMC environment prior to installing OKD on VMware vSphere. Ensure your VMC environment has the following prerequisites:
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Create a non-exclusive, DHCP-enabled, NSX-T network segment and subnet. Other virtual machines (VMs) can be hosted on the subnet, but at least eight IP addresses must be available for the OKD deployment.
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Allocate two IP addresses, outside the DHCP range, and configure them with reverse DNS records.
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A DNS record for
api.<cluster_name>.<base_domain>pointing to the allocated IP address. -
A DNS record for
*.apps.<cluster_name>.<base_domain>pointing to the allocated IP address.
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Configure the following firewall rules:
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An ANY:ANY firewall rule between the OKD compute network and the internet. This is used by nodes and applications to download container images.
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An ANY:ANY firewall rule between the installation host and the software-defined data center (SDDC) management network on port 443. This allows you to upload the Fedora CoreOS (FCOS) OVA during deployment.
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An HTTPS firewall rule between the OKD compute network and vCenter. This connection allows OKD to communicate with vCenter for provisioning and managing nodes, persistent volume claims (PVCs), and other resources.
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You must have the following information to deploy OKD:
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The OKD cluster name, such as
vmc-prod-1. -
The base DNS name, such as
companyname.com. -
If not using the default, the pod network CIDR and services network CIDR must be identified, which are set by default to
10.128.0.0/14and172.30.0.0/16, respectively. These CIDRs are used for pod-to-pod and pod-to-service communication and are not accessible externally; however, they must not overlap with existing subnets in your organization. -
The following vCenter information:
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vCenter hostname, username, and password
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Datacenter name, such as
SDDC-Datacenter -
Cluster name, such as
Cluster-1 -
Network name
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Datastore name, such as
WorkloadDatastoreIt is recommended to move your vSphere cluster to the VMC
Compute-ResourcePoolresource pool after your cluster installation is finished.
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A Linux-based host deployed to VMC as a bastion.
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The bastion host can be Fedora or any another Linux-based host; it must have internet connectivity and the ability to upload an OVA to the ESXi hosts.
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Download and install the OpenShift CLI tools to the bastion host.
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The
openshift-installinstallation program -
The OpenShift CLI (
oc) tool
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You cannot use the VMware NSX Container Plugin for Kubernetes (NCP), and NSX is not used as the OpenShift SDN. The version of NSX currently available with VMC is incompatible with the version of NCP certified with OKD. However, the NSX DHCP service is used for virtual machine IP management with the full-stack automated OKD deployment and with nodes provisioned, either manually or automatically, by the Machine API integration with vSphere. Additionally, NSX firewall rules are created to enable access with the OKD cluster and between the bastion host and the VMC vSphere hosts. |
VMC Sizer tool
VMware Cloud on AWS is built on top of AWS bare metal infrastructure; this is the same bare metal infrastructure which runs AWS native services. When a VMware cloud on AWS software-defined data center (SDDC) is deployed, you consume these physical server nodes and run the VMware ESXi hypervisor in a single tenant fashion. This means the physical infrastructure is not accessible to anyone else using VMC. It is important to consider how many physical hosts you will need to host your virtual infrastructure.
To determine this, VMware provides the VMC on AWS Sizer. With this tool, you can define the resources you intend to host on VMC:
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Types of workloads
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Total number of virtual machines
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Specification information such as:
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Storage requirements
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vCPUs
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vRAM
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Overcommit ratios
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With these details, the sizer tool can generate a report, based on VMware best practices, and recommend your cluster configuration and the number of hosts you will need.
vSphere prerequisites
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You reviewed details about the OKD installation and update processes.
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You read the documentation on selecting a cluster installation method and preparing it for users.
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You provisioned block registry storage. For more information on persistent storage, see Understanding persistent storage.
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If you use a firewall, you configured it to allow the sites that your cluster requires access to.
Be sure to also review this site list if you are configuring a proxy.
VMware vSphere infrastructure requirements
You must install the OKD cluster on a VMware vSphere version 6 or 7 instance that meets the requirements for the components that you use.
| Virtual environment product | Required version |
|---|---|
VM hardware version |
13 or later |
vSphere ESXi hosts |
6.5 or later |
vCenter host |
6.5 or later |
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Installing a cluster on VMware vSphere version 6.7U2 or earlier and virtual hardware version 13 is now deprecated. These versions are still fully supported, but support will be removed in a future version of OKD. Hardware version 15 is now the default for vSphere virtual machines in OKD. To update the hardware version for your vSphere nodes, see the "Updating hardware on nodes running in vSphere" article. |
| Component | Minimum supported versions | Description |
|---|---|---|
Hypervisor |
vSphere 6.5 and later with HW version 13 |
This version is the minimum version that Fedora CoreOS (FCOS) supports. See the Red Hat Enterprise Linux 8 supported hypervisors list. |
Storage with in-tree drivers |
vSphere 6.5 and later |
This plugin creates vSphere storage by using the in-tree storage drivers for vSphere included in OKD. |
If you use a vSphere version 6.5 instance, consider upgrading to 6.7U3 or 7.0 before you install OKD.
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You must ensure that the time on your ESXi hosts is synchronized before you install OKD. See Edit Time Configuration for a Host in the VMware documentation. |
Network connectivity requirements
You must configure the network connectivity between machines to allow OKD cluster components to communicate.
Review the following details about the required network ports.
| Protocol | Port | Description |
|---|---|---|
ICMP |
N/A |
Network reachability tests |
TCP |
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Metrics |
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Host level services, including the node exporter on ports |
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The default ports that Kubernetes reserves |
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openshift-sdn |
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UDP |
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virtual extensible LAN (VXLAN) |
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Geneve |
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Host level services, including the node exporter on ports |
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IPsec IKE packets |
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IPsec NAT-T packets |
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TCP/UDP |
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Kubernetes node port |
ESP |
N/A |
IPsec Encapsulating Security Payload (ESP) |
| Protocol | Port | Description |
|---|---|---|
TCP |
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Kubernetes API |
| Protocol | Port | Description |
|---|---|---|
TCP |
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etcd server and peer ports |
Additional resources
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To update the hardware version for your vSphere nodes, see Updating hardware on nodes running in vSphere.
vCenter requirements
Before you install an OKD cluster on your vCenter that uses infrastructure that the installer provisions, you must prepare your environment.
Required vCenter account privileges
To install an OKD cluster in a vCenter, the installation program requires access to an account with privileges to read and create the required resources. Using an account that has global administrative privileges is the simplest way to access all of the necessary permissions.
If you cannot use an account with global administrative privileges, you must create roles to grant the privileges necessary for OKD cluster installation. While most of the privileges are always required, some are required only if you plan for the installation program to provision a folder to contain the OKD cluster on your vCenter instance, which is the default behavior. You must create or amend vSphere roles for the specified objects to grant the required privileges.
An additional role is required if the installation program is to create a vSphere virtual machine folder.
Roles and privileges required for installation in vSphere API
| vSphere object for role | When required | Required privileges in vSphere API |
|---|---|---|
vSphere vCenter |
Always |
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vSphere vCenter Cluster |
Always |
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vSphere Datastore |
Always |
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vSphere Port Group |
Always |
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Virtual Machine Folder |
Always |
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vSphere vCenter Datacenter |
If the installation program creates the virtual machine folder |
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Roles and privileges required for installation in vCenter graphical user interface (GUI)
| vSphere object for role | When required | Required privileges in vCenter GUI |
|---|---|---|
vSphere vCenter |
Always |
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vSphere vCenter Cluster |
If VMs will be created in the cluster root |
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vSphere vCenter Resource Pool |
If an existing resource pool is provided |
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vSphere Datastore |
Always |
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vSphere Port Group |
Always |
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Virtual Machine Folder |
Always |
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vSphere vCenter Datacenter |
If the installation program creates the virtual machine folder |
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Additionally, the user requires some ReadOnly permissions, and some of the roles require permission to propogate the permissions to child objects. These settings vary depending on whether or not you install the cluster into an existing folder.
Required permissions and propagation settings
| vSphere object | Folder type | Propagate to children | Permissions required |
|---|---|---|---|
vSphere vCenter |
Always |
False |
Listed required privileges |
vSphere vCenter Datacenter |
Existing folder |
False |
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Installation program creates the folder |
True |
Listed required privileges |
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vSphere vCenter Cluster |
Always |
True |
Listed required privileges |
vSphere vCenter Datastore |
Always |
False |
Listed required privileges |
vSphere Switch |
Always |
False |
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vSphere Port Group |
Always |
False |
Listed required privileges |
vSphere vCenter Virtual Machine Folder |
Existing folder |
True |
Listed required privileges |
For more information about creating an account with only the required privileges, see vSphere Permissions and User Management Tasks in the vSphere documentation.
Using OKD with vMotion
If you intend on using vMotion in your vSphere environment, consider the following before installing a OKD cluster.
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OKD generally supports compute-only vMotion. Using Storage vMotion can cause issues and is not supported.
To help ensure the uptime of your compute and control plane nodes, it is recommended that you follow the VMware best practices for vMotion. It is also recommended to use VMware anti-affinity rules to improve the availability of OKD during maintenance or hardware issues.
For more information about vMotion and anti-affinity rules, see the VMware vSphere documentation for vMotion networking requirements and VM anti-affinity rules.
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If you are using vSphere volumes in your pods, migrating a VM across datastores either manually or through Storage vMotion causes, invalid references within OKD persistent volume (PV) objects. These references prevent affected pods from starting up and can result in data loss.
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Similarly, OKD does not support selective migration of VMDKs across datastores, using datastore clusters for VM provisioning or for dynamic or static provisioning of PVs, or using a datastore that is part of a datastore cluster for dynamic or static provisioning of PVs.
Cluster resources
When you deploy an OKD cluster that uses installer-provisioned infrastructure, the installation program must be able to create several resources in your vCenter instance.
A standard OKD installation creates the following vCenter resources:
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1 Folder
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1 Tag category
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1 Tag
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Virtual machines:
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1 template
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1 temporary bootstrap node
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3 control plane nodes
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3 compute machines
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Although these resources use 856 GB of storage, the bootstrap node is destroyed during the cluster installation process. A minimum of 800 GB of storage is required to use a standard cluster.
If you deploy more compute machines, the OKD cluster will use more storage.
Cluster limits
Available resources vary between clusters. The number of possible clusters within a vCenter is limited primarily by available storage space and any limitations on the number of required resources. Be sure to consider both limitations to the vCenter resources that the cluster creates and the resources that you require to deploy a cluster, such as IP addresses and networks.
Networking requirements
You must use DHCP for the network and ensure that the DHCP server is configured to provide persistent IP addresses to the cluster machines. You must configure the default gateway to use the DHCP server. All nodes must be in the same VLAN. You cannot scale the cluster using a second VLAN as a Day 2 operation. Additionally, you must create the following networking resources before you install the OKD cluster:
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It is recommended that each OKD node in the cluster must have access to a Network Time Protocol (NTP) server that is discoverable via DHCP. Installation is possible without an NTP server. However, asynchronous server clocks will cause errors, which NTP server prevents. |
Required IP Addresses
An installer-provisioned vSphere installation requires two static IP addresses:
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The API address is used to access the cluster API.
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The Ingress address is used for cluster ingress traffic.
You must provide these IP addresses to the installation program when you install the OKD cluster.
DNS records
You must create DNS records for two static IP addresses in the appropriate DNS server for the vCenter instance that hosts your OKD cluster. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify when you install the cluster. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..
| Component | Record | Description |
|---|---|---|
API VIP |
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This DNS A/AAAA or CNAME record must point to the load balancer for the control plane machines. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
Ingress VIP |
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A wildcard DNS A/AAAA or CNAME record that points to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
Generating a key pair for cluster node SSH access
During an OKD installation, you can provide an SSH public key to the installation program. The key is passed to the Fedora CoreOS (FCOS) 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 FCOS 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.
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Do not skip this procedure in production environments, where disaster recovery and debugging is required. |
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You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs. |
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On clusters running Fedora CoreOS (FCOS), the SSH keys specified in the Ignition config files are written to the |
Procedure
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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~/.sshdirectory.If you plan to install an OKD cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the
x86_64architecture, do not create a key that uses theed25519algorithm. Instead, create a key that uses thersaorecdsaalgorithm. -
View the public SSH key:
$ cat <path>/<file_name>.pubFor example, run the following to view the
~/.ssh/id_ed25519.pubpublic 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 gathercommand.On some distributions, default SSH private key identities such as
~/.ssh/id_rsaand~/.ssh/id_dsaare managed automatically.-
If the
ssh-agentprocess is not already running for your local user, start it as a background task:$ eval "$(ssh-agent -s)"Example outputAgent pid 31874If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.
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Add your SSH private key to the
ssh-agent:$ ssh-add <path>/<file_name> (1)1 Specify the path and file name for your SSH private key, such as ~/.ssh/id_ed25519Example outputIdentity added: /home/<you>/<path>/<file_name> (<computer_name>)
Next steps
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When you install OKD, provide the SSH public key to the installation program.
Obtaining the installation program
Before you install OKD, download the installation file on a local computer.
Prerequisites
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You have a computer that runs Linux or macOS, with 500 MB of local disk space
Procedure
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Download installer from https://github.com/openshift/okd/releases
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 OKD uninstallation procedures for your specific cloud provider.
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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 OKD components.
Using a pull secret from the Red Hat OpenShift Cluster Manager is not required. You can use a pull secret for another private registry. Or, if you do not need the cluster to pull images from a private registry, you can use
{"auths":{"fake":{"auth":"aWQ6cGFzcwo="}}}as the pull secret when prompted during the installation.If you do not use the pull secret from the Red Hat OpenShift Cluster Manager:
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Red Hat Operators are not available.
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The Telemetry and Insights operators do not send data to Red Hat.
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Content from the Red Hat Container Catalog registry, such as image streams and Operators, are not available.
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Adding vCenter root CA certificates to your system trust
Because the installation program requires access to your vCenter’s API, you must add your vCenter’s trusted root CA certificates to your system trust before you install an OKD cluster.
Procedure
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From the vCenter home page, download the vCenter’s root CA certificates. Click Download trusted root CA certificates in the vSphere Web Services SDK section. The
<vCenter>/certs/download.zipfile downloads. -
Extract the compressed file that contains the vCenter root CA certificates. The contents of the compressed file resemble the following file structure:
certs ├── lin │ ├── 108f4d17.0 │ ├── 108f4d17.r1 │ ├── 7e757f6a.0 │ ├── 8e4f8471.0 │ └── 8e4f8471.r0 ├── mac │ ├── 108f4d17.0 │ ├── 108f4d17.r1 │ ├── 7e757f6a.0 │ ├── 8e4f8471.0 │ └── 8e4f8471.r0 └── win ├── 108f4d17.0.crt ├── 108f4d17.r1.crl ├── 7e757f6a.0.crt ├── 8e4f8471.0.crt └── 8e4f8471.r0.crl 3 directories, 15 files -
Add the files for your operating system to the system trust. For example, on a Fedora operating system, run the following command:
# cp certs/lin/* /etc/pki/ca-trust/source/anchors -
Update your system trust. For example, on a Fedora operating system, run the following command:
# update-ca-trust extract
Deploying the cluster
You can install OKD on a compatible cloud platform.
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You can run the |
Prerequisites
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Configure an account with the cloud platform that hosts your cluster.
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Obtain the OKD installation program and the pull secret for your cluster.
Procedure
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Change to the directory that contains the installation program and initialize the cluster deployment:
$ ./openshift-install create cluster --dir <installation_directory> \ (1) --log-level=info (2)1 For <installation_directory>, specify the directory name to store the files that the installation program creates.2 To view different installation details, specify warn,debug, orerrorinstead ofinfo.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 OKD version.
Provide values at the prompts:
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Optional: Select an SSH key to use to access your cluster machines.
For production OKD clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your
ssh-agentprocess uses. -
Select vsphere as the platform to target.
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Specify the name of your vCenter instance.
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Specify the user name and password for the vCenter account that has the required permissions to create the cluster.
The installation program connects to your vCenter instance.
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Select the datacenter in your vCenter instance to connect to.
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Select the default vCenter datastore to use.
Datastore and cluster names cannot exceed 60 characters; therefore, ensure the combined string length does not exceed the 60 character limit.
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Select the vCenter cluster to install the OKD cluster in. The installation program uses the root resource pool of the vSphere cluster as the default resource pool.
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Select the network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured.
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Enter the virtual IP address that you configured for control plane API access.
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Enter the virtual IP address that you configured for cluster ingress.
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Enter the base domain. This base domain must be the same one that you used in the DNS records that you configured.
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Enter a descriptive name for your cluster. The cluster name must be the same one that you used in the DNS records that you configured.
Datastore and cluster names cannot exceed 60 characters; therefore, ensure the combined string length does not exceed the 60 character limit.
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Paste the pull secret from the Red Hat OpenShift Cluster Manager.
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If you do not have a pull secret from the Red Hat OpenShift Cluster Manager, you can paste the pull secret another private registry.
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If you do not need the cluster to pull images from a private registry, you can paste
{"auths":{"fake":{"auth":"aWQ6cGFzcwo="}}}as the pull secret.
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Use the
openshift-installcommand from the bastion hosted in the VMC environment.If the cloud provider account that you configured on your host does not have sufficient permissions to deploy the cluster, the installation process stops, and the missing permissions are displayed.
When the cluster deployment completes, directions for accessing your cluster, including a link to its web console and credentials for the
kubeadminuser, display in your terminal.Example output... INFO Install complete! INFO To access the cluster as the system:admin user when using 'oc', run 'export KUBECONFIG=/home/myuser/install_dir/auth/kubeconfig' INFO Access the OpenShift web-console here: https://console-openshift-console.apps.mycluster.example.com INFO Login to the console with user: "kubeadmin", and password: "4vYBz-Ee6gm-ymBZj-Wt5AL" INFO Time elapsed: 36m22sThe cluster access and credential information also outputs to
<installation_directory>/.openshift_install.logwhen an installation succeeds.-
The Ignition config files that the 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-bootstrappercertificate 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.
You must not delete the installation program or the files that the installation program creates. Both are required to delete the cluster.
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Installing the OpenShift CLI by downloading the binary
You can install the OpenShift CLI (oc) to interact with OKD from a
command-line interface. You can install oc on Linux, Windows, or macOS.
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If you installed an earlier version of |
Installing the OpenShift CLI on Linux
You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.
Procedure
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Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.
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Download
oc.tar.gz. -
Unpack the archive:
$ tar xvf <file> -
Place the
ocbinary in a directory that is on yourPATH.To check your
PATH, execute the following command:$ echo $PATH
After you install the OpenShift CLI, it is available using the oc command:
$ oc <command>Installing the OpenShift CLI on Windows
You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.
Procedure
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Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.
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Download
oc.zip. -
Unzip the archive with a ZIP program.
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Move the
ocbinary to a directory that is on yourPATH.To check your
PATH, open the command prompt and execute the following command:C:\> path
After you install the OpenShift CLI, it is available using the oc command:
C:\> oc <command>Installing the OpenShift CLI on macOS
You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.
Procedure
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Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.
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Download
oc.tar.gz. -
Unpack and unzip the archive.
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Move the
ocbinary to a directory on your PATH.To check your
PATH, open a terminal and execute the following command:$ echo $PATH
After you install the OpenShift CLI, it is available using the oc command:
$ oc <command>Logging in to the cluster by using the CLI
You can log in to your cluster as a default system user by exporting the cluster kubeconfig file.
The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server.
The file is specific to a cluster and is created during OKD installation.
Prerequisites
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You deployed an OKD cluster.
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You installed the
ocCLI.
Procedure
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Export the
kubeadmincredentials:$ export KUBECONFIG=<installation_directory>/auth/kubeconfig (1)1 For <installation_directory>, specify the path to the directory that you stored the installation files in. -
Verify you can run
occommands successfully using the exported configuration:$ oc whoamiExample outputsystem:admin
Creating registry storage
After you install the cluster, you must create storage for the registry Operator.
Image registry removed during installation
On platforms that do not provide shareable object storage, the OpenShift Image
Registry Operator bootstraps itself as Removed. This allows
openshift-installer to complete installations on these platform types.
After installation, you must edit the Image Registry Operator configuration to
switch the managementState from Removed to Managed.
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The Prometheus console provides an "Image Registry has been removed. |
Image registry storage configuration
The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.
Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.
Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.
Configuring registry storage for VMware vSphere
As a cluster administrator, following installation you must configure your registry to use storage.
Prerequisites
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Cluster administrator permissions.
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A cluster on VMware vSphere.
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Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.
OKD supports
ReadWriteOnceaccess for image registry storage when you have only one replica.ReadWriteOnceaccess also requires that the registry uses theRecreaterollout strategy. To deploy an image registry that supports high availability with two or more replicas,ReadWriteManyaccess is required. -
Must have "100Gi" capacity.
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Testing shows issues with using the NFS server on RHEL as storage backend for core services. This includes the OpenShift Container Registry and Quay, Prometheus for monitoring storage, and Elasticsearch for logging storage. Therefore, using RHEL NFS to back PVs used by core services is not recommended. Other NFS implementations on the marketplace might not have these issues. Contact the individual NFS implementation vendor for more information on any testing that was possibly completed against these OKD core components. |
Procedure
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To configure your registry to use storage, change the
spec.storage.pvcin theconfigs.imageregistry/clusterresource.When using shared storage, review your security settings to prevent outside access.
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Verify that you do not have a registry pod:
$ oc get pod -n openshift-image-registry -l docker-registry=defaultExample outputNo resourses found in openshift-image-registry namespaceIf you do have a registry pod in your output, you do not need to continue with this procedure.
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Check the registry configuration:
$ oc edit configs.imageregistry.operator.openshift.ioExample outputstorage: pvc: claim: (1)1 Leave the claimfield blank to allow the automatic creation of animage-registry-storagepersistent volume claim (PVC). The PVC is generated based on the default storage class. However, be aware that the default storage class might provide ReadWriteOnce (RWO) volumes, such as a RADOS Block Device (RBD), which can cause issues when replicating to more than one replica. -
Check the
clusteroperatorstatus:$ oc get clusteroperator image-registryExample outputNAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE MESSAGE image-registry 4.7 True False False 6h50m
Configuring block registry storage for VMware vSphere
To allow the image registry to use block storage types such as vSphere Virtual Machine Disk (VMDK) during upgrades as a cluster administrator, you can use the Recreate rollout strategy.
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Block storage volumes are supported but not recommended for use with image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica. |
Procedure
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To set the image registry storage as a block storage type, patch the registry so that it uses the
Recreaterollout strategy and runs with only1replica:$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}' -
Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.
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Create a
pvc.yamlfile with the following contents to define a VMware vSpherePersistentVolumeClaimobject:kind: PersistentVolumeClaim apiVersion: v1 metadata: name: image-registry-storage (1) namespace: openshift-image-registry (2) spec: accessModes: - ReadWriteOnce (3) resources: requests: storage: 100Gi (4)1 A unique name that represents the PersistentVolumeClaimobject.2 The namespace for the PersistentVolumeClaimobject, which isopenshift-image-registry.3 The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node.4 The size of the persistent volume claim. -
Create the
PersistentVolumeClaimobject from the file:$ oc create -f pvc.yaml -n openshift-image-registry
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Edit the registry configuration so that it references the correct PVC:
$ oc edit config.imageregistry.operator.openshift.io -o yamlExample outputstorage: pvc: claim: (1)1 Creating a custom PVC allows you to leave the claimfield blank for the default automatic creation of animage-registry-storagePVC.
For instructions about configuring registry storage so that it references the correct PVC, see Configuring the registry for vSphere.
Backing up VMware vSphere volumes
OKD provisions new volumes as independent persistent disks to freely attach and detach the volume on any node in the cluster. As a consequence, it is not possible to back up volumes that use snapshots, or to restore volumes from snapshots. See Snapshot Limitations for more information.
Procedure
To create a backup of persistent volumes:
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Stop the application that is using the persistent volume.
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Clone the persistent volume.
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Restart the application.
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Create a backup of the cloned volume.
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Delete the cloned volume.
Steal clock accounting
By default, the installation program provisions the cluster’s virtual machines without enabling the steal clock accounting parameter (stealclock.enabled). Enabling steal clock accounting can help with troubleshooting cluster issues. After the cluster is deployed, use the vSphere Client to enable this parameter on each of the virtual machines.
For more information, see this Red Hat knowledge base article.
Additional resources
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See About remote health monitoring for more information about the Telemetry service
Next steps
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If necessary, you can opt out of remote health reporting.
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Optional: View the events from the vSphere Problem Detector Operator to determine if the cluster has permission or storage configuration issues.