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Installing a cluster on vSphere with network customizations

In OpenShift Container Platform version 4.16, you can install a cluster on your VMware vSphere instance by using installer-provisioned infrastructure with customized network configuration options. By customizing your network configuration, your cluster can coexist with existing IP address allocations in your environment and integrate with existing MTU and VXLAN configurations. To customize the installation, you modify parameters in the install-config.yaml file before you install the cluster.

You must set most of the network configuration parameters during installation, and you can modify only kubeProxy configuration parameters in a running cluster.

OpenShift Container Platform supports deploying a cluster to a single VMware vCenter only. Deploying a cluster with machines/machine sets on multiple vCenters is not supported.

Prerequisites

Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.16, 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.

VMware vSphere region and zone enablement

You can deploy an OpenShift Container Platform cluster to multiple vSphere data centers that run in a single VMware vCenter. Each data center can run multiple clusters. This configuration reduces the risk of a hardware failure or network outage that can cause your cluster to fail. To enable regions and zones, you must define multiple failure domains for your OpenShift Container Platform cluster.

The VMware vSphere region and zone enablement feature requires the vSphere Container Storage Interface (CSI) driver as the default storage driver in the cluster. As a result, the feature is only available on a newly installed cluster.

For a cluster that was upgraded from a previous release, you must enable CSI automatic migration for the cluster. You can then configure multiple regions and zones for the upgraded cluster.

The default installation configuration deploys a cluster to a single vSphere data center. If you want to deploy a cluster to multiple vSphere data centers, you must create an installation configuration file that enables the region and zone feature.

The default install-config.yaml file includes vcenters and failureDomains fields, where you can specify multiple vSphere data centers and clusters for your OpenShift Container Platform cluster. You can leave these fields blank if you want to install an OpenShift Container Platform cluster in a vSphere environment that consists of single data center.

The following list describes terms associated with defining zones and regions for your cluster:

  • Failure domain: Establishes the relationships between a region and zone. You define a failure domain by using vCenter objects, such as a datastore object. A failure domain defines the vCenter location for OpenShift Container Platform cluster nodes.

  • Region: Specifies a vCenter data center. You define a region by using a tag from the openshift-region tag category.

  • Zone: Specifies a vCenter cluster. You define a zone by using a tag from the openshift-zone tag category.

If you plan on specifying more than one failure domain in your install-config.yaml file, you must create tag categories, zone tags, and region tags in advance of creating the configuration file.

You must create a vCenter tag for each vCenter data center, which represents a region. Additionally, you must create a vCenter tag for each cluster than runs in a data center, which represents a zone. After you create the tags, you must attach each tag to their respective data centers and clusters.

The following table outlines an example of the relationship among regions, zones, and tags for a configuration with multiple vSphere data centers running in a single VMware vCenter.

Data center (region) Cluster (zone) Tags

us-east

us-east-1

us-east-1a

us-east-1b

us-east-2

us-east-2a

us-east-2b

us-west

us-west-1

us-west-1a

us-west-1b

us-west-2

us-west-2a

us-west-2b
Additional resources

Creating the installation configuration file

You can customize the OpenShift Container Platform cluster you install on VMware vSphere.

Prerequisites

  • You have the OpenShift Container Platform installation program and the pull secret for your cluster.

Procedure

  1. Create the install-config.yaml file.

    1. 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.

      When specifying the directory:

      • Verify that the directory has the execute permission. This permission is required to run Terraform binaries under the installation directory.

      • Use an empty directory. Some installation assets, such as bootstrap X.509 certificates, have short expiration intervals, therefore 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.

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

      1. 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.

      2. Select vsphere as the platform to target.

      3. Specify the name of your vCenter instance.

      4. 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.

      5. Select the data center in your vCenter instance to connect to.

        After you create the installation configuration file, you can modify the file to create a multiple vSphere data center environment. This means that you can deploy an OpenShift Container Platform cluster to multiple vSphere data centers that run in a single VMware vCenter. For more information about creating this environment, see the section named VMware vSphere region and zone enablement.

      6. Select the default vCenter datastore to use.

        You can specify the path of any datastore that exists in a datastore cluster. By default, Storage Distributed Resource Scheduler (SDRS), which uses Storage vMotion, is automatically enabled for a datastore cluster. Red Hat does not support Storage vMotion, so you must disable Storage DRS to avoid data loss issues for your OpenShift Container Platform cluster.

        You cannot specify more than one datastore path. If you must specify VMs across multiple datastores, use a datastore object to specify a failure domain in your cluster’s install-config.yaml configuration file. For more information, see "VMware vSphere region and zone enablement".

      7. Select the vCenter cluster to install the OpenShift Container Platform cluster in. The installation program uses the root resource pool of the vSphere cluster as the default resource pool.

      8. Select the network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured.

      9. Enter the virtual IP address that you configured for control plane API access.

      10. Enter the virtual IP address that you configured for cluster ingress.

      11. Enter the base domain. This base domain must be the same one that you used in the DNS records that you configured.

      12. Enter a descriptive name for your cluster.

        The cluster name you enter must match the cluster name you specified when configuring the DNS records.

  2. Modify the install-config.yaml file. You can find more information about the available parameters in the "Installation configuration parameters" section.

  3. 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.
Additional resources

Sample install-config.yaml file for an installer-provisioned VMware vSphere cluster

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com (1)
compute: (2)
- architecture: amd64
  name:  <worker_node>
  platform: {}
  replicas: 3
controlPlane: (2)
  architecture: amd64
  name: <parent_node>
  platform: {}
  replicas: 3
metadata:
  creationTimestamp: null
  name: test (3)
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 10.0.0.0/16
  networkType: OVNKubernetes (11)
  serviceNetwork:
  - 172.30.0.0/16
platform:
  vsphere: (4)
    apiVIPs:
      - 10.0.0.1
    failureDomains: (5)
    - name: <failure_domain_name>
      region: <default_region_name>
      server: <fully_qualified_domain_name>
      topology:
        computeCluster: "/<data_center>/host/<cluster>"
        datacenter: <data_center>
        datastore: "/<data_center>/datastore/<datastore>" (6)
        networks:
        - <VM_Network_name>
        resourcePool: "/<data_center>/host/<cluster>/Resources/<resourcePool>" (7)
        folder: "/<data_center_name>/vm/<folder_name>/<subfolder_name>"
        tagIDs: (8)
        - <tag_id>  (9)
      zone: <default_zone_name>
    ingressVIPs:
    - 10.0.0.2
    vcenters:
    - datacenters:
      - <data_center>
      password: <password>
      port: 443
      server: <fully_qualified_domain_name>
      user: administrator@vsphere.local
    diskType: thin (10)
fips: false
pullSecret: '{"auths": ...}'
sshKey: 'ssh-ed25519 AAAA...'
1 The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Only one control plane pool is used.
3 The cluster name that you specified in your DNS records.
4 Optional: Provides additional configuration for the machine pool parameters for the compute and control plane machines.
5 Establishes the relationships between a region and zone. You define a failure domain by using vCenter objects, such as a datastore object. A failure domain defines the vCenter location for OpenShift Container Platform cluster nodes.
6 The path to the vSphere datastore that holds virtual machine files, templates, and ISO images.

You can specify the path of any datastore that exists in a datastore cluster. By default, Storage vMotion is automatically enabled for a datastore cluster. Red Hat does not support Storage vMotion, so you must disable Storage vMotion to avoid data loss issues for your OpenShift Container Platform cluster.

If you must specify VMs across multiple datastores, use a datastore object to specify a failure domain in your cluster’s install-config.yaml configuration file. For more information, see "VMware vSphere region and zone enablement".
7 Optional: Provides an existing resource pool for machine creation. If you do not specify a value, the installation program uses the root resource pool of the vSphere cluster.
8 Optional: Each VM created by OpenShift Container Platform is assigned a unique tag that is specific to the cluster. The assigned tag enables the installation program to identify and remove the associated VMs when a cluster is decommissioned. You can list up to ten additional tag IDs to be attached to the VMs provisioned by the installation program.
9 The ID of the tag to be associated by the installation program. For example, urn:vmomi:InventoryServiceTag:208e713c-cae3-4b7f-918e-4051ca7d1f97:GLOBAL. For more information about determining the tag ID, see the vSphere Tags and Attributes documentation.
10 The vSphere disk provisioning method.
11 The cluster network plugin to install. The default value OVNKubernetes is the only supported value.

In OpenShift Container Platform 4.12 and later, the apiVIP and ingressVIP configuration settings are deprecated. Instead, use a list format to enter values in the apiVIPs and ingressVIPs configuration settings.

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

  1. 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-----
additionalTrustBundlePolicy: <policy_to_add_additionalTrustBundle> (5)
    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. You must include vCenter’s IP address and the IP range that you use for its machines.
    4 If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the trustedCA field of the Proxy object. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
    5 Optional: The policy to determine the configuration of the Proxy object to reference the user-ca-bundle config map in the trustedCA field. The allowed values are Proxyonly and Always. Use Proxyonly to reference the user-ca-bundle config map only when http/https proxy is configured. Use Always to always reference the user-ca-bundle config map. The default value is Proxyonly.

    The installation program does not support the proxy readinessEndpoints field.

    If the installer times out, restart and then complete the deployment by using the wait-for command of the installer. For example:

    $ ./openshift-install wait-for install-complete --log-level debug

  2. 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.

Optional: Deploying with dual-stack networking

For dual-stack networking in OpenShift Container Platform clusters, you can configure IPv4 and IPv6 address endpoints for cluster nodes. To configure IPv4 and IPv6 address endpoints for cluster nodes, edit the machineNetwork, clusterNetwork, and serviceNetwork configuration settings in the install-config.yaml file. Each setting must have two CIDR entries each. For a cluster with the IPv4 family as the primary address family, specify the IPv4 setting first. For a cluster with the IPv6 family as the primary address family, specify the IPv6 setting first.

machineNetwork:
- cidr: {{ extcidrnet }}
- cidr: {{ extcidrnet6 }}
clusterNetwork:
- cidr: 10.128.0.0/14
  hostPrefix: 23
- cidr: fd02::/48
  hostPrefix: 64
serviceNetwork:
- 172.30.0.0/16
- fd03::/112

To provide an interface to the cluster for applications that use IPv4 and IPv6 addresses, configure IPv4 and IPv6 virtual IP (VIP) address endpoints for the Ingress VIP and API VIP services. To configure IPv4 and IPv6 address endpoints, edit the apiVIPs and ingressVIPs configuration settings in the install-config.yaml file . The apiVIPs and ingressVIPs configuration settings use a list format. The order of the list indicates the primary and secondary VIP address for each service.

platform:
  vsphere:
    apiVIPs:
      - <api_ipv4>
      - <api_ipv6>
    ingressVIPs:
      - <wildcard_ipv4>
      - <wildcard_ipv6>

For a cluster with dual-stack networking configuration, you must assign both IPv4 and IPv6 addresses to the same interface.

Configuring regions and zones for a VMware vCenter

You can modify the default installation configuration file, so that you can deploy an OpenShift Container Platform cluster to multiple vSphere data centers that run in a single VMware vCenter.

The default install-config.yaml file configuration from the previous release of OpenShift Container Platform is deprecated. You can continue to use the deprecated default configuration, but the openshift-installer will prompt you with a warning message that indicates the use of deprecated fields in the configuration file.

The example uses the govc command. The govc command is an open source command available from VMware; it is not available from Red Hat. The Red Hat support team does not maintain the govc command. Instructions for downloading and installing govc are found on the VMware documentation website
Prerequisites

  • You have an existing install-config.yaml installation configuration file.

    You must specify at least one failure domain for your OpenShift Container Platform cluster, so that you can provision data center objects for your VMware vCenter server. Consider specifying multiple failure domains if you need to provision virtual machine nodes in different data centers, clusters, datastores, and other components. To enable regions and zones, you must define multiple failure domains for your OpenShift Container Platform cluster.
Procedure

  1. Enter the following govc command-line tool commands to create the openshift-region and openshift-zone vCenter tag categories:

    If you specify different names for the openshift-region and openshift-zone vCenter tag categories, the installation of the OpenShift Container Platform cluster fails.

    		 
    $ govc tags.category.create -d "OpenShift region" openshift-region
    $ govc tags.category.create -d "OpenShift zone" openshift-zone

  2. To create a region tag for each region vSphere data center where you want to deploy your cluster, enter the following command in your terminal:

    $ govc tags.create -c <region_tag_category> <region_tag>

  3. To create a zone tag for each vSphere cluster where you want to deploy your cluster, enter the following command:

    $ govc tags.create -c <zone_tag_category> <zone_tag>

  4. Attach region tags to each vCenter data center object by entering the following command:

    $ govc tags.attach -c <region_tag_category> <region_tag_1> /<data_center_1>

  5. Attach the zone tags to each vCenter data center object by entering the following command:

    $ govc tags.attach -c <zone_tag_category> <zone_tag_1> /<data_center_1>/host/vcs-mdcnc-workload-1

  6. Change to the directory that contains the installation program and initialize the cluster deployment according to your chosen installation requirements.

Sample install-config.yaml file with multiple data centers defined in a vSphere center
---
compute:
---
  vsphere:
      zones:
        - "<machine_pool_zone_1>"
        - "<machine_pool_zone_2>"
---
controlPlane:
---
vsphere:
      zones:
        - "<machine_pool_zone_1>"
        - "<machine_pool_zone_2>"
---
platform:
  vsphere:
    vcenters:
---
    datacenters:
      - <data_center_1_name>
      - <data_center_2_name>
    failureDomains:
    - name: <machine_pool_zone_1>
      region: <region_tag_1>
      zone: <zone_tag_1>
      server: <fully_qualified_domain_name>
      topology:
        datacenter: <data_center_1>
        computeCluster: "/<data_center_1>/host/<cluster1>"
        networks:
        - <VM_Network1_name>
        datastore: "/<data_center_1>/datastore/<datastore1>"
        resourcePool: "/<data_center_1>/host/<cluster1>/Resources/<resourcePool1>"
        folder: "/<data_center_1>/vm/<folder1>"
    - name: <machine_pool_zone_2>
      region: <region_tag_2>
      zone: <zone_tag_2>
      server: <fully_qualified_domain_name>
      topology:
        datacenter: <data_center_2>
        computeCluster: "/<data_center_2>/host/<cluster2>"
        networks:
        - <VM_Network2_name>
        datastore: "/<data_center_2>/datastore/<datastore2>"
        resourcePool: "/<data_center_2>/host/<cluster2>/Resources/<resourcePool2>"
        folder: "/<data_center_2>/vm/<folder2>"
---

Network configuration phases

There are two phases prior to OpenShift Container Platform installation where you can customize the network configuration.

Phase 1

You can customize the following network-related fields in the install-config.yaml file before you create the manifest files:

  • networking.networkType

  • networking.clusterNetwork

  • networking.serviceNetwork

  • networking.machineNetwork

    For more information, see "Installation configuration parameters".

    Set the networking.machineNetwork to match the Classless Inter-Domain Routing (CIDR) where the preferred subnet is located.

    The CIDR range 172.17.0.0/16 is reserved by libVirt. You cannot use any other CIDR range that overlaps with the 172.17.0.0/16 CIDR range for networks in your cluster.
Phase 2

After creating the manifest files by running openshift-install create manifests, you can define a customized Cluster Network Operator manifest with only the fields you want to modify. You can use the manifest to specify advanced network configuration.

During phase 2, you cannot override the values that you specified in phase 1 in the install-config.yaml file. However, you can customize the network plugin during phase 2.

Specifying advanced network configuration

You can use advanced network configuration for your network plugin to integrate your cluster into your existing network environment.

You can specify advanced network configuration only before you install the cluster.

Customizing your network configuration by modifying the OpenShift Container Platform manifest files created by the installation program is not supported. Applying a manifest file that you create, as in the following procedure, is supported.
Prerequisites

  • You have created the install-config.yaml file and completed any modifications to it.

Procedure

  1. Change to the directory that contains the installation program and create the manifests:

    $ ./openshift-install create manifests --dir <installation_directory> (1)
    1 <installation_directory> specifies the name of the directory that contains the install-config.yaml file for your cluster.

  2. Create a stub manifest file for the advanced network configuration that is named cluster-network-03-config.yml in the <installation_directory>/manifests/ directory:

    apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:

  3. Specify the advanced network configuration for your cluster in the cluster-network-03-config.yml file, such as in the following example:

    Enable IPsec for the OVN-Kubernetes network provider
    apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    ovnKubernetesConfig:
      ipsecConfig:
        mode: Full

  4. Optional: Back up the manifests/cluster-network-03-config.yml file. The installation program consumes the manifests/ directory when you create the Ignition config files.

  5. Remove the Kubernetes manifest files that define the control plane machines and compute machineSets:

    $ rm -f openshift/99_openshift-cluster-api_master-machines-*.yaml openshift/99_openshift-cluster-api_worker-machineset-*.yaml

    Because you create and manage these resources yourself, you do not have to initialize them.

    • You can preserve the MachineSet files to create compute machines by using the machine API, but you must update references to them to match your environment.

Specifying multiple subnets for your network

Before you install an OpenShift Container Platform cluster on a vSphere host, you can specify multiple subnets for a networking implementation so that the vSphere cloud controller manager (CCM) can select the appropriate subnet for a given networking situation. vSphere can use the subnet for managing pods and services on your cluster.

For this configuration, you must specify internal and external Classless Inter-Domain Routing (CIDR) implementations in the vSphere CCM configuration. Each CIDR implementation lists an IP address range that the CCM uses to decide what subnets interact with traffic from internal and external networks.

Failure to configure internal and external CIDR implementations in the vSphere CCM configuration can cause the vSphere CCM to select the wrong subnet. This situation causes the following error:

ERROR Bootstrap failed to complete: timed out waiting for the condition
ERROR Failed to wait for bootstrapping to complete. This error usually happens when there is a problem with control plane hosts that prevents the control plane operators from creating the control plane.

This configuration can cause new nodes that associate with a MachineSet object with a single subnet to become unusable as each new node receives the node.cloudprovider.kubernetes.io/uninitialized taint. These situations can cause communication issues with the Kubernetes API server that can cause installation of the cluster to fail.
Prerequisites

  • You created Kubernetes manifest files for your OpenShift Container Platform cluster.

Procedure

  1. From the directory where you store your OpenShift Container Platform cluster manifest files, open the manifests/cluster-infrastructure-02-config.yml manifest file.

  2. Add a nodeNetworking object to the file and specify internal and external network subnet CIDR implementations for the object.

    For most networking situations, consider setting the standard multiple-subnet configuration. This configuration requires that you set the same IP address ranges in the nodeNetworking.internal.networkSubnetCidr and nodeNetworking.external.networkSubnetCidr parameters.
    Example of a configured cluster-infrastructure-02-config.yml manifest file
    apiVersion: config.openshift.io/v1
kind: Infrastructure
metadata:
  name: cluster
spec:
  cloudConfig:
    key: config
    name: cloud-provider-config
  platformSpec:
    type: VSphere
    vsphere:
      failureDomains:
      - name: generated-failure-domain
      ...
       nodeNetworking:
         external:
           networkSubnetCidr:
           - <machine_network_cidr_ipv4>
           - <machine_network_cidr_ipv6>
         internal:
           networkSubnetCidr:
           - <machine_network_cidr_ipv4>
           - <machine_network_cidr_ipv6>
# ...
Additional resources

Cluster Network Operator configuration

The configuration for the cluster network is specified as part of the Cluster Network Operator (CNO) configuration and stored in a custom resource (CR) object that is named cluster. The CR specifies the fields for the Network API in the operator.openshift.io API group.

The CNO configuration inherits the following fields during cluster installation from the Network API in the Network.config.openshift.io API group:

clusterNetwork

IP address pools from which pod IP addresses are allocated.

serviceNetwork

IP address pool for services.

defaultNetwork.type

Cluster network plugin. OVNKubernetes is the only supported plugin during installation.

You can specify the cluster network plugin configuration for your cluster by setting the fields for the defaultNetwork object in the CNO object named cluster.

Cluster Network Operator configuration object

The fields for the Cluster Network Operator (CNO) are described in the following table:

Table 1. Cluster Network Operator configuration object
Field Type Description

metadata.name

string

The name of the CNO object. This name is always cluster.

spec.clusterNetwork

array

A list specifying the blocks of IP addresses from which pod IP addresses are allocated and the subnet prefix length assigned to each individual node in the cluster. For example:

spec:
  clusterNetwork:
  - cidr: 10.128.0.0/19
    hostPrefix: 23
  - cidr: 10.128.32.0/19
    hostPrefix: 23

spec.serviceNetwork

array

A block of IP addresses for services. The OpenShift SDN and OVN-Kubernetes network plugins support only a single IP address block for the service network. For example:

spec:
  serviceNetwork:
  - 172.30.0.0/14

You can customize this field only in the install-config.yaml file before you create the manifests. The value is read-only in the manifest file.

spec.defaultNetwork

object

Configures the network plugin for the cluster network.

spec.kubeProxyConfig

object

The fields for this object specify the kube-proxy configuration. If you are using the OVN-Kubernetes cluster network plugin, the kube-proxy configuration has no effect.

defaultNetwork object configuration

The values for the defaultNetwork object are defined in the following table:

Table 2. defaultNetwork object
Field Type Description

type

string

OVNKubernetes. The Red Hat OpenShift Networking network plugin is selected during installation. This value cannot be changed after cluster installation.

OpenShift Container Platform uses the OVN-Kubernetes network plugin by default. OpenShift SDN is no longer available as an installation choice for new clusters.

ovnKubernetesConfig

object

This object is only valid for the OVN-Kubernetes network plugin.
Configuration for the OVN-Kubernetes network plugin

The following table describes the configuration fields for the OVN-Kubernetes network plugin:

Table 3. ovnKubernetesConfig object
Field Type Description

mtu

integer

The maximum transmission unit (MTU) for the Geneve (Generic Network Virtualization Encapsulation) overlay network. This is detected automatically based on the MTU of the primary network interface. You do not normally need to override the detected MTU.

If the auto-detected value is not what you expect it to be, confirm that the MTU on the primary network interface on your nodes is correct. You cannot use this option to change the MTU value of the primary network interface on the nodes.

If your cluster requires different MTU values for different nodes, you must set this value to 100 less than the lowest MTU value in your cluster. For example, if some nodes in your cluster have an MTU of 9001, and some have an MTU of 1500, you must set this value to 1400.

genevePort

integer

The port to use for all Geneve packets. The default value is 6081. This value cannot be changed after cluster installation.

ipsecConfig

object

Specify a configuration object for customizing the IPsec configuration.

ipv4

object

Specifies a configuration object for IPv4 settings.

ipv6

object

Specifies a configuration object for IPv6 settings.

policyAuditConfig

object

Specify a configuration object for customizing network policy audit logging. If unset, the defaults audit log settings are used.

gatewayConfig

object

Optional: Specify a configuration object for customizing how egress traffic is sent to the node gateway.

While migrating egress traffic, you can expect some disruption to workloads and service traffic until the Cluster Network Operator (CNO) successfully rolls out the changes.
Table 4. ovnKubernetesConfig.ipv4 object
Field Type Description

internalTransitSwitchSubnet

string

If your existing network infrastructure overlaps with the 100.88.0.0/16 IPv4 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. The subnet for the distributed transit switch that enables east-west traffic. This subnet cannot overlap with any other subnets used by OVN-Kubernetes or on the host itself. It must be large enough to accommodate one IP address per node in your cluster.

The default value is 100.88.0.0/16.

internalJoinSubnet

string

If your existing network infrastructure overlaps with the 100.64.0.0/16 IPv4 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. You must ensure that the IP address range does not overlap with any other subnet used by your OpenShift Container Platform installation. The IP address range must be larger than the maximum number of nodes that can be added to the cluster. For example, if the clusterNetwork.cidr value is 10.128.0.0/14 and the clusterNetwork.hostPrefix value is /23, then the maximum number of nodes is 2^(23-14)=512.

The default value is 100.64.0.0/16.
Table 5. ovnKubernetesConfig.ipv6 object
Field Type Description

internalTransitSwitchSubnet

string

If your existing network infrastructure overlaps with the fd97::/64 IPv6 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. The subnet for the distributed transit switch that enables east-west traffic. This subnet cannot overlap with any other subnets used by OVN-Kubernetes or on the host itself. It must be large enough to accommodate one IP address per node in your cluster.

The default value is fd97::/64.

internalJoinSubnet

string

If your existing network infrastructure overlaps with the fd98::/64 IPv6 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. You must ensure that the IP address range does not overlap with any other subnet used by your OpenShift Container Platform installation. The IP address range must be larger than the maximum number of nodes that can be added to the cluster.

The default value is fd98::/64.
Table 6. policyAuditConfig object
Field Type Description

rateLimit

integer

The maximum number of messages to generate every second per node. The default value is 20 messages per second.

maxFileSize

integer

The maximum size for the audit log in bytes. The default value is 50000000 or 50 MB.

maxLogFiles

integer

The maximum number of log files that are retained.

destination

string

One of the following additional audit log targets:

libc

The libc syslog() function of the journald process on the host.

udp:<host>:<port>

A syslog server. Replace <host>:<port> with the host and port of the syslog server.

unix:<file>

A Unix Domain Socket file specified by <file>.

null

Do not send the audit logs to any additional target.

syslogFacility

string

The syslog facility, such as kern, as defined by RFC5424. The default value is local0.
Table 7. gatewayConfig object
Field Type Description

routingViaHost

boolean

Set this field to true to send egress traffic from pods to the host networking stack. For highly-specialized installations and applications that rely on manually configured routes in the kernel routing table, you might want to route egress traffic to the host networking stack. By default, egress traffic is processed in OVN to exit the cluster and is not affected by specialized routes in the kernel routing table. The default value is false.

This field has an interaction with the Open vSwitch hardware offloading feature. If you set this field to true, you do not receive the performance benefits of the offloading because egress traffic is processed by the host networking stack.

ipForwarding

object

You can control IP forwarding for all traffic on OVN-Kubernetes managed interfaces by using the ipForwarding specification in the Network resource. Specify Restricted to only allow IP forwarding for Kubernetes related traffic. Specify Global to allow forwarding of all IP traffic. For new installations, the default is Restricted. For updates to OpenShift Container Platform 4.14 or later, the default is Global.

ipv4

object

Optional: Specify an object to configure the internal OVN-Kubernetes masquerade address for host to service traffic for IPv4 addresses.

ipv6

object

Optional: Specify an object to configure the internal OVN-Kubernetes masquerade address for host to service traffic for IPv6 addresses.
Table 8. gatewayConfig.ipv4 object
Field Type Description

internalMasqueradeSubnet

string

The masquerade IPv4 addresses that are used internally to enable host to service traffic. The host is configured with these IP addresses as well as the shared gateway bridge interface. The default value is 169.254.169.0/29.
Table 9. gatewayConfig.ipv6 object
Field Type Description

internalMasqueradeSubnet

string

The masquerade IPv6 addresses that are used internally to enable host to service traffic. The host is configured with these IP addresses as well as the shared gateway bridge interface. The default value is fd69::/125.
Table 10. ipsecConfig object
Field Type Description

mode

string

Specifies the behavior of the IPsec implementation. Must be one of the following values:

  • Disabled: IPsec is not enabled on cluster nodes.

  • External: IPsec is enabled for network traffic with external hosts.

  • Full: IPsec is enabled for pod traffic and network traffic with external hosts.
Example OVN-Kubernetes configuration with IPSec enabled
defaultNetwork:
  type: OVNKubernetes
  ovnKubernetesConfig:
    mtu: 1400
    genevePort: 6081
      ipsecConfig:
        mode: Full

Using OVNKubernetes can lead to a stack exhaustion problem on IBM Power®.

kubeProxyConfig object configuration (OpenShiftSDN container network interface only)

The values for the kubeProxyConfig object are defined in the following table:

Table 11. kubeProxyConfig object
Field Type Description

iptablesSyncPeriod

string

The refresh period for iptables rules. The default value is 30s. Valid suffixes include s, m, and h and are described in the Go time package documentation.

Because of performance improvements introduced in OpenShift Container Platform 4.3 and greater, adjusting the iptablesSyncPeriod parameter is no longer necessary.

proxyArguments.iptables-min-sync-period

array

The minimum duration before refreshing iptables rules. This field ensures that the refresh does not happen too frequently. Valid suffixes include s, m, and h and are described in the Go time package. The default value is:

kubeProxyConfig:
  proxyArguments:
    iptables-min-sync-period:
    - 0s

Services for a user-managed load balancer

You can configure an OpenShift Container Platform cluster to use a user-managed load balancer in place of the default load balancer.

Configuring a user-managed load balancer depends on your vendor’s load balancer.

The information and examples in this section are for guideline purposes only. Consult the vendor documentation for more specific information about the vendor’s load balancer.

Red Hat supports the following services for a user-managed load balancer:

  • Ingress Controller

  • OpenShift API

  • OpenShift MachineConfig API

You can choose whether you want to configure one or all of these services for a user-managed load balancer. Configuring only the Ingress Controller service is a common configuration option. To better understand each service, view the following diagrams:

An image that shows an example network workflow of an Ingress Controller operating in an OpenShift Container Platform environment.
Figure 1. Example network workflow that shows an Ingress Controller operating in an OpenShift Container Platform environment
An image that shows an example network workflow of an OpenShift API operating in an OpenShift Container Platform environment.
Figure 2. Example network workflow that shows an OpenShift API operating in an OpenShift Container Platform environment
An image that shows an example network workflow of an OpenShift MachineConfig API operating in an OpenShift Container Platform environment.
Figure 3. Example network workflow that shows an OpenShift MachineConfig API operating in an OpenShift Container Platform environment

The following configuration options are supported for user-managed load balancers:

  • Use a node selector to map the Ingress Controller to a specific set of nodes. You must assign a static IP address to each node in this set, or configure each node to receive the same IP address from the Dynamic Host Configuration Protocol (DHCP). Infrastructure nodes commonly receive this type of configuration.

  • Target all IP addresses on a subnet. This configuration can reduce maintenance overhead, because you can create and destroy nodes within those networks without reconfiguring the load balancer targets. If you deploy your ingress pods by using a machine set on a smaller network, such as a /27 or /28, you can simplify your load balancer targets.

    You can list all IP addresses that exist in a network by checking the machine config pool’s resources.

Before you configure a user-managed load balancer for your OpenShift Container Platform cluster, consider the following information:

  • For a front-end IP address, you can use the same IP address for the front-end IP address, the Ingress Controller’s load balancer, and API load balancer. Check the vendor’s documentation for this capability.

  • For a back-end IP address, ensure that an IP address for an OpenShift Container Platform control plane node does not change during the lifetime of the user-managed load balancer. You can achieve this by completing one of the following actions:

    • Assign a static IP address to each control plane node.

    • Configure each node to receive the same IP address from the DHCP every time the node requests a DHCP lease. Depending on the vendor, the DHCP lease might be in the form of an IP reservation or a static DHCP assignment.

  • Manually define each node that runs the Ingress Controller in the user-managed load balancer for the Ingress Controller back-end service. For example, if the Ingress Controller moves to an undefined node, a connection outage can occur.

Configuring a user-managed load balancer

You can configure an OpenShift Container Platform cluster to use a user-managed load balancer in place of the default load balancer.

Before you configure a user-managed load balancer, ensure that you read the "Services for a user-managed load balancer" section.

Read the following prerequisites that apply to the service that you want to configure for your user-managed load balancer.

MetalLB, which runs on a cluster, functions as a user-managed load balancer.
OpenShift API prerequisites

  • You defined a front-end IP address.

  • TCP ports 6443 and 22623 are exposed on the front-end IP address of your load balancer. Check the following items:

    • Port 6443 provides access to the OpenShift API service.

    • Port 22623 can provide ignition startup configurations to nodes.

  • The front-end IP address and port 6443 are reachable by all users of your system with a location external to your OpenShift Container Platform cluster.

  • The front-end IP address and port 22623 are reachable only by OpenShift Container Platform nodes.

  • The load balancer backend can communicate with OpenShift Container Platform control plane nodes on port 6443 and 22623.

Ingress Controller prerequisites

  • You defined a front-end IP address.

  • TCP ports 443 and 80 are exposed on the front-end IP address of your load balancer.

  • The front-end IP address, port 80 and port 443 are be reachable by all users of your system with a location external to your OpenShift Container Platform cluster.

  • The front-end IP address, port 80 and port 443 are reachable to all nodes that operate in your OpenShift Container Platform cluster.

  • The load balancer backend can communicate with OpenShift Container Platform nodes that run the Ingress Controller on ports 80, 443, and 1936.

Prerequisite for health check URL specifications

You can configure most load balancers by setting health check URLs that determine if a service is available or unavailable. OpenShift Container Platform provides these health checks for the OpenShift API, Machine Configuration API, and Ingress Controller backend services.

The following examples show health check specifications for the previously listed backend services:

Example of a Kubernetes API health check specification
Path: HTTPS:6443/readyz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10
Example of a Machine Config API health check specification
Path: HTTPS:22623/healthz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10
Example of an Ingress Controller health check specification
Path: HTTP:1936/healthz/ready
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 5
Interval: 10
Procedure

  1. Configure the HAProxy Ingress Controller, so that you can enable access to the cluster from your load balancer on ports 6443, 22623, 443, and 80. Depending on your needs, you can specify the IP address of a single subnet or IP addresses from multiple subnets in your HAProxy configuration.

    Example HAProxy configuration with one listed subnet
    # ...
listen my-cluster-api-6443
    bind 192.168.1.100:6443
    mode tcp
    balance roundrobin
  option httpchk
  http-check connect
  http-check send meth GET uri /readyz
  http-check expect status 200
    server my-cluster-master-2 192.168.1.101:6443 check inter 10s rise 2 fall 2
    server my-cluster-master-0 192.168.1.102:6443 check inter 10s rise 2 fall 2
    server my-cluster-master-1 192.168.1.103:6443 check inter 10s rise 2 fall 2

listen my-cluster-machine-config-api-22623
    bind 192.168.1.100:22623
    mode tcp
    balance roundrobin
  option httpchk
  http-check connect
  http-check send meth GET uri /healthz
  http-check expect status 200
    server my-cluster-master-2 192.168.1.101:22623 check inter 10s rise 2 fall 2
    server my-cluster-master-0 192.168.1.102:22623 check inter 10s rise 2 fall 2
    server my-cluster-master-1 192.168.1.103:22623 check inter 10s rise 2 fall 2

listen my-cluster-apps-443
    bind 192.168.1.100:443
    mode tcp
    balance roundrobin
  option httpchk
  http-check connect
  http-check send meth GET uri /healthz/ready
  http-check expect status 200
    server my-cluster-worker-0 192.168.1.111:443 check port 1936 inter 10s rise 2 fall 2
    server my-cluster-worker-1 192.168.1.112:443 check port 1936 inter 10s rise 2 fall 2
    server my-cluster-worker-2 192.168.1.113:443 check port 1936 inter 10s rise 2 fall 2

listen my-cluster-apps-80
   bind 192.168.1.100:80
   mode tcp
   balance roundrobin
  option httpchk
  http-check connect
  http-check send meth GET uri /healthz/ready
  http-check expect status 200
    server my-cluster-worker-0 192.168.1.111:80 check port 1936 inter 10s rise 2 fall 2
    server my-cluster-worker-1 192.168.1.112:80 check port 1936 inter 10s rise 2 fall 2
    server my-cluster-worker-2 192.168.1.113:80 check port 1936 inter 10s rise 2 fall 2
# ...
    Example HAProxy configuration with multiple listed subnets
    # ...
listen api-server-6443
    bind *:6443
    mode tcp
      server master-00 192.168.83.89:6443 check inter 1s
      server master-01 192.168.84.90:6443 check inter 1s
      server master-02 192.168.85.99:6443 check inter 1s
      server bootstrap 192.168.80.89:6443 check inter 1s

listen machine-config-server-22623
    bind *:22623
    mode tcp
      server master-00 192.168.83.89:22623 check inter 1s
      server master-01 192.168.84.90:22623 check inter 1s
      server master-02 192.168.85.99:22623 check inter 1s
      server bootstrap 192.168.80.89:22623 check inter 1s

listen ingress-router-80
    bind *:80
    mode tcp
    balance source
      server worker-00 192.168.83.100:80 check inter 1s
      server worker-01 192.168.83.101:80 check inter 1s

listen ingress-router-443
    bind *:443
    mode tcp
    balance source
      server worker-00 192.168.83.100:443 check inter 1s
      server worker-01 192.168.83.101:443 check inter 1s

listen ironic-api-6385
    bind *:6385
    mode tcp
    balance source
      server master-00 192.168.83.89:6385 check inter 1s
      server master-01 192.168.84.90:6385 check inter 1s
      server master-02 192.168.85.99:6385 check inter 1s
      server bootstrap 192.168.80.89:6385 check inter 1s

listen inspector-api-5050
    bind *:5050
    mode tcp
    balance source
      server master-00 192.168.83.89:5050 check inter 1s
      server master-01 192.168.84.90:5050 check inter 1s
      server master-02 192.168.85.99:5050 check inter 1s
      server bootstrap 192.168.80.89:5050 check inter 1s
# ...

  2. Use the curl CLI command to verify that the user-managed load balancer and its resources are operational:

    1. Verify that the cluster machine configuration API is accessible to the Kubernetes API server resource, by running the following command and observing the response:

      $ curl https://<loadbalancer_ip_address>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
  "major": "1",
  "minor": "11+",
  "gitVersion": "v1.11.0+ad103ed",
  "gitCommit": "ad103ed",
  "gitTreeState": "clean",
  "buildDate": "2019-01-09T06:44:10Z",
  "goVersion": "go1.10.3",
  "compiler": "gc",
  "platform": "linux/amd64"
}

    2. Verify that the cluster machine configuration API is accessible to the Machine config server resource, by running the following command and observing the output:

      $ curl -v https://<loadbalancer_ip_address>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
Content-Length: 0

    3. Verify that the controller is accessible to the Ingress Controller resource on port 80, by running the following command and observing the output:

      $ curl -I -L -H "Host: console-openshift-console.apps.<cluster_name>.<base_domain>" http://<load_balancer_front_end_IP_address>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
content-length: 0
location: https://console-openshift-console.apps.ocp4.private.opequon.net/
cache-control: no-cache

    4. Verify that the controller is accessible to the Ingress Controller resource on port 443, by running the following command and observing the output:

      $ curl -I -L --insecure --resolve console-openshift-console.apps.<cluster_name>.<base_domain>:443:<Load Balancer Front End IP Address> https://console-openshift-console.apps.<cluster_name>.<base_domain>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
referrer-policy: strict-origin-when-cross-origin
set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
x-content-type-options: nosniff
x-dns-prefetch-control: off
x-frame-options: DENY
x-xss-protection: 1; mode=block
date: Wed, 04 Oct 2023 16:29:38 GMT
content-type: text/html; charset=utf-8
set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
cache-control: private

  3. Configure the DNS records for your cluster to target the front-end IP addresses of the user-managed load balancer. You must update records to your DNS server for the cluster API and applications over the load balancer.

    Examples of modified DNS records
    <load_balancer_ip_address>  A  api.<cluster_name>.<base_domain>
A record pointing to Load Balancer Front End
    <load_balancer_ip_address>   A apps.<cluster_name>.<base_domain>
A record pointing to Load Balancer Front End

    DNS propagation might take some time for each DNS record to become available. Ensure that each DNS record propagates before validating each record.

  4. For your OpenShift Container Platform cluster to use the user-managed load balancer, you must specify the following configuration in your cluster’s install-config.yaml file:

    # ...
platform:
  vsphere:
    loadBalancer:
      type: UserManaged (1)
      apiVIPs:
      - <api_ip> (2)
      ingressVIPs:
      - <ingress_ip> (3)
# ...
    1 Set UserManaged for the type parameter to specify a user-managed load balancer for your cluster. The parameter defaults to OpenShiftManagedDefault, which denotes the default internal load balancer. For services defined in an openshift-kni-infra namespace, a user-managed load balancer can deploy the coredns service to pods in your cluster but ignores keepalived and haproxy services.
    2 Required parameter when you specify a user-managed load balancer. Specify the user-managed load balancer’s public IP address, so that the Kubernetes API can communicate with the user-managed load balancer.
    3 Required parameter when you specify a user-managed load balancer. Specify the user-managed load balancer’s public IP address, so that the user-managed load balancer can manage ingress traffic for your cluster.
Verification

  1. Use the curl CLI command to verify that the user-managed load balancer and DNS record configuration are operational:

    1. Verify that you can access the cluster API, by running the following command and observing the output:

      $ curl https://api.<cluster_name>.<base_domain>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
  "major": "1",
  "minor": "11+",
  "gitVersion": "v1.11.0+ad103ed",
  "gitCommit": "ad103ed",
  "gitTreeState": "clean",
  "buildDate": "2019-01-09T06:44:10Z",
  "goVersion": "go1.10.3",
  "compiler": "gc",
  "platform": "linux/amd64"
  }

    2. Verify that you can access the cluster machine configuration, by running the following command and observing the output:

      $ curl -v https://api.<cluster_name>.<base_domain>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
Content-Length: 0

    3. Verify that you can access each cluster application on port, by running the following command and observing the output:

      $ curl http://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
content-length: 0
location: https://console-openshift-console.apps.<cluster-name>.<base domain>/
cache-control: no-cacheHTTP/1.1 200 OK
referrer-policy: strict-origin-when-cross-origin
set-cookie: csrf-token=39HoZgztDnzjJkq/JuLJMeoKNXlfiVv2YgZc09c3TBOBU4NI6kDXaJH1LdicNhN1UsQWzon4Dor9GWGfopaTEQ==; Path=/; Secure
x-content-type-options: nosniff
x-dns-prefetch-control: off
x-frame-options: DENY
x-xss-protection: 1; mode=block
date: Tue, 17 Nov 2020 08:42:10 GMT
content-type: text/html; charset=utf-8
set-cookie: 1e2670d92730b515ce3a1bb65da45062=9b714eb87e93cf34853e87a92d6894be; path=/; HttpOnly; Secure; SameSite=None
cache-control: private

    4. Verify that you can access each cluster application on port 443, by running the following command and observing the output:

      $ curl https://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
referrer-policy: strict-origin-when-cross-origin
set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
x-content-type-options: nosniff
x-dns-prefetch-control: off
x-frame-options: DENY
x-xss-protection: 1; mode=block
date: Wed, 04 Oct 2023 16:29:38 GMT
content-type: text/html; charset=utf-8
set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
cache-control: private

Deploying the cluster

You can install OpenShift Container Platform on a compatible cloud platform.

You can run the create cluster command of the installation program only once, during initial installation.
Prerequisites

  • You have the OpenShift Container Platform installation program and the pull secret for your cluster.

  • You have verified that the cloud provider account on your host has the correct permissions to deploy the cluster. An account with incorrect permissions causes the installation process to fail with an error message that displays the missing permissions.

  • Optional: Before you create the cluster, configure an external load balancer in place of the default load balancer.

    You do not need to specify API and Ingress static addresses for your installation program. If you choose this configuration, you must take additional actions to define network targets that accept an IP address from each referenced vSphere subnet. See the section "Configuring a user-managed load balancer".
Procedure

  • 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 location of your customized ./install-config.yaml file.
    2 To view different installation details, specify warn, debug, or error instead of info.
Verification

When the cluster deployment completes successfully:

  • The terminal displays directions for accessing your cluster, including a link to the web console and credentials for the kubeadmin user.

  • Credential information also outputs to <installation_directory>/.openshift_install.log.

Do not delete the installation program or the files that the installation program creates. Both are required to delete the cluster.
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: "password"
INFO Time elapsed: 36m22s

  • 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-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.

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 OpenShift Container Platform installation.

Prerequisites

  • You deployed an OpenShift Container Platform cluster.

  • You installed the oc CLI.

Procedure

  1. 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.

  2. Verify you can run oc commands successfully using the exported configuration:

    $ oc whoami
    Example output
    system: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. When this has completed, you must configure storage.

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

  • Cluster administrator permissions.

  • A cluster on VMware vSphere.

  • Persistent storage provisioned for your cluster, such as Red Hat OpenShift Data Foundation.

    OpenShift Container Platform supports ReadWriteOnce access for image registry storage when you have only one replica. ReadWriteOnce access also requires that the registry uses the Recreate rollout strategy. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.

  • Must have "100Gi" capacity.

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 OpenShift Container Platform core components.
Procedure

  1. To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.

    When you use shared storage, review your security settings to prevent outside access.

  2. Verify that you do not have a registry pod:

    $ oc get pod -n openshift-image-registry -l docker-registry=default
    Example output
    No resourses found in openshift-image-registry namespace

    If you do have a registry pod in your output, you do not need to continue with this procedure.

  3. Check the registry configuration:

    $ oc edit configs.imageregistry.operator.openshift.io
    Example output
    storage:
  pvc:
    claim: (1)
    1 Leave the claim field blank to allow the automatic creation of an image-registry-storage persistent 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 you replicate to more than one replica.

  4. Check the clusteroperator status:

    $ oc get clusteroperator image-registry
    Example output
    NAME             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.

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

  1. Enter the following command to set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy, and runs with only 1 replica:

    $ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'

  2. 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.

    1. Create a pvc.yaml file with the following contents to define a VMware vSphere PersistentVolumeClaim object:

      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 PersistentVolumeClaim object.
      2 The namespace for the PersistentVolumeClaim object, which is openshift-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.

    2. Enter the following command to create the PersistentVolumeClaim object from the file:

      $ oc create -f pvc.yaml -n openshift-image-registry

  3. Enter the following command to edit the registry configuration so that it references the correct PVC:

    $ oc edit config.imageregistry.operator.openshift.io -o yaml
    Example output
    storage:
  pvc:
    claim: (1)
    1 By creating a custom PVC, you can leave the claim field blank for the default automatic creation of an image-registry-storage PVC.

For instructions about configuring registry storage so that it references the correct PVC, see Configuring the registry for vSphere.

Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.16, the Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to OpenShift Cluster Manager.

After you confirm that your OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually by using OpenShift Cluster Manager, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.

Additional resources

Configuring network components to run on the control plane

You can configure networking components to run exclusively on the control plane nodes. By default, OpenShift Container Platform allows any node in the machine config pool to host the ingressVIP virtual IP address. However, some environments deploy compute nodes in separate subnets from the control plane nodes, which requires configuring the ingressVIP virtual IP address to run on the control plane nodes.

You can scale the remote nodes by creating a compute machine set in a separate subnet.

When deploying remote nodes in separate subnets, you must place the ingressVIP virtual IP address exclusively with the control plane nodes.
Installer-provisioned networking
Procedure

  1. Change to the directory storing the install-config.yaml file:

    $ cd ~/clusterconfigs

  2. Switch to the manifests subdirectory:

    $ cd manifests

  3. Create a file named cluster-network-avoid-workers-99-config.yaml:

    $ touch cluster-network-avoid-workers-99-config.yaml

  4. Open the cluster-network-avoid-workers-99-config.yaml file in an editor and enter a custom resource (CR) that describes the Operator configuration:

    apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  name: 50-worker-fix-ipi-rwn
  labels:
    machineconfiguration.openshift.io/role: worker
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - path: /etc/kubernetes/manifests/keepalived.yaml
          mode: 0644
          contents:
            source: data:,

    This manifest places the ingressVIP virtual IP address on the control plane nodes. Additionally, this manifest deploys the following processes on the control plane nodes only:

    • openshift-ingress-operator

    • keepalived

  5. Save the cluster-network-avoid-workers-99-config.yaml file.

  6. Create a manifests/cluster-ingress-default-ingresscontroller.yaml file:

    apiVersion: operator.openshift.io/v1
kind: IngressController
metadata:
  name: default
  namespace: openshift-ingress-operator
spec:
  nodePlacement:
    nodeSelector:
      matchLabels:
        node-role.kubernetes.io/master: ""

  7. Consider backing up the manifests directory. The installer deletes the manifests/ directory when creating the cluster.

  8. Modify the cluster-scheduler-02-config.yml manifest to make the control plane nodes schedulable by setting the mastersSchedulable field to true. Control plane nodes are not schedulable by default. For example:

    $ sed -i "s;mastersSchedulable: false;mastersSchedulable: true;g" clusterconfigs/manifests/cluster-scheduler-02-config.yml

    If control plane nodes are not schedulable after completing this procedure, deploying the cluster will fail.

Next steps