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Installing a cluster on IBM Cloud with network customizations

In OKD version 4.16, you can install a cluster with a customized network configuration on infrastructure that the installation program provisions on IBM Cloud®. 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.

Prerequisites

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.

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

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

On clusters running Fedora CoreOS (FCOS), the SSH keys specified in the Ignition config files are written to the /home/core/.ssh/authorized_keys.d/core file. However, the Machine Config Operator manages SSH keys in the /home/core/.ssh/authorized_keys file and configures sshd to ignore the /home/core/.ssh/authorized_keys.d/core file. As a result, newly provisioned OKD nodes are not accessible using SSH until the Machine Config Operator reconciles the machine configs with the authorized_keys file. After you can access the nodes using SSH, you can delete the /home/core/.ssh/authorized_keys.d/core file.
Procedure

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

    $ ssh-keygen -t ed25519 -N '' -f <path>/<file_name> (1)
    1 Specify the path and file name, such as ~/.ssh/id_ed25519, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.

    If you plan to install an OKD cluster that uses the Fedora cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. View the public SSH key:

    $ cat <path>/<file_name>.pub

    For example, run the following to view the ~/.ssh/id_ed25519.pub public key:

    $ cat ~/.ssh/id_ed25519.pub

  3. Add the SSH private key identity to the SSH agent for your local user, if it has not already been added. SSH agent management of the key is required for password-less SSH authentication onto your cluster nodes, or if you want to use the ./openshift-install gather command.

    On some distributions, default SSH private key identities such as ~/.ssh/id_rsa and ~/.ssh/id_dsa are managed automatically.

    1. If the ssh-agent process is not already running for your local user, start it as a background task:

      $ eval "$(ssh-agent -s)"
      Example output
      Agent pid 31874

      If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

  4. Add your SSH private key to the ssh-agent:

    $ ssh-add <path>/<file_name> (1)
    1 Specify the path and file name for your SSH private key, such as ~/.ssh/id_ed25519
    Example output
    Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
Next steps

  • When you install OKD, provide the SSH public key to the installation program.

Obtaining the installation program

Before you install OKD, download the installation file on the host you are using for installation.

Prerequisites

  • You have a computer that runs Linux or macOS, with at least 1.2 GB of local disk space.

Procedure

  1. Download the installation program 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 of the 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.

  2. 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

  3. Download your installation pull secret from 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 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 Red Hat OpenShift Cluster Manager:

    • Red Hat Operators are not available.

    • The Telemetry and Insights operators do not send data to Red Hat.

    • Content from the Red Hat Ecosystem Catalog Container images registry, such as image streams and Operators, are not available.

Exporting the API key

You must set the API key you created as a global variable; the installation program ingests the variable during startup to set the API key.

Prerequisites

  • You have created either a user API key or service ID API key for your IBM Cloud® account.

Procedure

  • Export your API key for your account as a global variable:

    $ export IC_API_KEY=<api_key>

You must set the variable name exactly as specified; the installation program expects the variable name to be present during startup.

Creating the installation configuration file

You can customize the OKD cluster you install on IBM Cloud®.

Prerequisites

  • You have the OKD 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 OKD 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 OKD clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

      2. Select ibmcloud as the platform to target.

      3. Select the region to deploy the cluster to.

      4. Select the base domain to deploy the cluster to. The base domain corresponds to the public DNS zone that you created for your cluster.

      5. Enter a descriptive name for your cluster.

  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

Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 1. Minimum resource requirements
Machine Operating System vCPU Virtual RAM Storage Input/Output Per Second (IOPS)

Bootstrap

FCOS

4

16 GB

100 GB

300

Control plane

FCOS

4

16 GB

100 GB

300

Compute

FCOS

2

8 GB

100 GB

300

As of OKD version 4.13, RHCOS is based on RHEL version 9.2, which updates the micro-architecture requirements. The following list contains the minimum instruction set architectures (ISA) that each architecture requires:

  • x86-64 architecture requires x86-64-v2 ISA

  • ARM64 architecture requires ARMv8.0-A ISA

  • IBM Power architecture requires Power 9 ISA

  • s390x architecture requires z14 ISA

For more information, see RHEL Architectures.

If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OKD.

Tested instance types for IBM Cloud

The following IBM Cloud® instance types have been tested with OKD.

Machine series

  • bx2-8x32

  • bx2d-4x16

  • bx3d-4x20

  • bx3dc-8x40

  • cx2-8x16

  • cx2d-4x8

  • cx3d-8x20

  • cx3dc-4x10

  • gx2-8x64x1v100

  • gx3-16x80x1l4

  • mx2-8x64

  • mx2d-4x32

  • mx3d-4x40

  • ox2-8x64

  • ux2d-2x56

  • vx2d-4x56

Additional resources

Sample customized install-config.yaml file for IBM Cloud

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

This sample YAML file is provided for reference only. You must obtain your install-config.yaml file by using the installation program and then modify it.

 
apiVersion: v1
baseDomain: example.com (1)
controlPlane:  (2) (3)
  hyperthreading: Enabled (4)
  name: master
  platform:
    ibmcloud: {}
  replicas: 3
compute:  (2) (3)
- hyperthreading: Enabled (4)
  name: worker
  platform:
    ibmcloud: {}
  replicas: 3
metadata:
  name: test-cluster (1)
networking: (2)
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 10.0.0.0/16
  networkType: OVNKubernetes (5)
  serviceNetwork:
  - 172.30.0.0/16
platform:
  ibmcloud:
    region: us-south (1)
credentialsMode: Manual
publish: External
pullSecret: '{"auths": ...}' (1)
sshKey: ssh-ed25519 AAAA... (6)
1 Required. The installation program prompts you for this value.
2 If you do not provide these parameters and values, the installation program provides the default value.
3 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.
4 Enables or disables simultaneous multithreading, also known as Hyper-Threading. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable simultaneous multithreading in some cluster machines, you must disable it in all cluster machines.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance. Use larger machine types, such as n1-standard-8, for your machines if you disable simultaneous multithreading.
5 The cluster network plugin to install. The default value OVNKubernetes is the only supported value.
6 Optional: provide the sshKey value that you use to access the machines in your cluster.

For production OKD clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

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 OKD 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 OpenStack, 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.
    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 Fedora CoreOS (FCOS) 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 FCOS 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 OKD.

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.

Manually creating IAM

Installing the cluster requires that the Cloud Credential Operator (CCO) operate in manual mode. While the installation program configures the CCO for manual mode, you must specify the identity and access management secrets for you cloud provider.

You can use the Cloud Credential Operator (CCO) utility (ccoctl) to create the required IBM Cloud® resources.

Prerequisites

  • You have configured the ccoctl binary.

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

Procedure

  1. Edit the install-config.yaml configuration file so that it contains the credentialsMode parameter set to Manual.

    Example install-config.yaml configuration file
    apiVersion: v1
baseDomain: cluster1.example.com
credentialsMode: Manual (1)
compute:
- architecture: amd64
  hyperthreading: Enabled
    1 This line is added to set the credentialsMode parameter to Manual.

  2. To generate the manifests, run the following command from the directory that contains the installation program:

    $ ./openshift-install create manifests --dir <installation_directory>

  3. From the directory that contains the installation program, set a $RELEASE_IMAGE variable with the release image from your installation file by running the following command:

    $ RELEASE_IMAGE=$(./openshift-install version | awk '/release image/ {print $3}')

  4. Extract the list of CredentialsRequest custom resources (CRs) from the OKD release image by running the following command:

    $ oc adm release extract \
  --from=$RELEASE_IMAGE \
  --credentials-requests \
  --included \(1)
  --install-config=<path_to_directory_with_installation_configuration>/install-config.yaml \(2)
  --to=<path_to_directory_for_credentials_requests> (3)
    1 The --included parameter includes only the manifests that your specific cluster configuration requires.
    2 Specify the location of the install-config.yaml file.
    3 Specify the path to the directory where you want to store the CredentialsRequest objects. If the specified directory does not exist, this command creates it.

    This command creates a YAML file for each CredentialsRequest object.

    Sample CredentialsRequest object
      apiVersion: cloudcredential.openshift.io/v1
  kind: CredentialsRequest
  metadata:
    labels:
      controller-tools.k8s.io: "1.0"
    name: openshift-image-registry-ibmcos
    namespace: openshift-cloud-credential-operator
  spec:
    secretRef:
      name: installer-cloud-credentials
      namespace: openshift-image-registry
    providerSpec:
      apiVersion: cloudcredential.openshift.io/v1
      kind: IBMCloudProviderSpec
      policies:
      - attributes:
        - name: serviceName
          value: cloud-object-storage
        roles:
        - crn:v1:bluemix:public:iam::::role:Viewer
        - crn:v1:bluemix:public:iam::::role:Operator
        - crn:v1:bluemix:public:iam::::role:Editor
        - crn:v1:bluemix:public:iam::::serviceRole:Reader
        - crn:v1:bluemix:public:iam::::serviceRole:Writer
      - attributes:
        - name: resourceType
          value: resource-group
        roles:
        - crn:v1:bluemix:public:iam::::role:Viewer

  5. Create the service ID for each credential request, assign the policies defined, create an API key, and generate the secret:

    $ ccoctl ibmcloud create-service-id \
  --credentials-requests-dir=<path_to_credential_requests_directory> \(1)
  --name=<cluster_name> \(2)
  --output-dir=<installation_directory> \(3)
  --resource-group-name=<resource_group_name> (4)
    1 Specify the directory containing the files for the component CredentialsRequest objects.
    2 Specify the name of the OKD cluster.
    3 Optional: Specify the directory in which you want the ccoctl utility to create objects. By default, the utility creates objects in the directory in which the commands are run.
    4 Optional: Specify the name of the resource group used for scoping the access policies.

    If your cluster uses Technology Preview features that are enabled by the TechPreviewNoUpgrade feature set, you must include the --enable-tech-preview parameter.

    If an incorrect resource group name is provided, the installation fails during the bootstrap phase. To find the correct resource group name, run the following command:

    $ grep resourceGroupName <installation_directory>/manifests/cluster-infrastructure-02-config.yml
Verification

  • Ensure that the appropriate secrets were generated in your cluster’s manifests directory.

Network configuration phases

There are two phases prior to OKD 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 OKD 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.

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 2. 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 3. 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.

OKD 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 4. 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 5. 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 OKD 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 6. 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 OKD 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 7. 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 8. 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 OKD 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 9. 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 10. 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 11. 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 12. 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 OKD 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

Deploying the cluster

You can install OKD on a compatible cloud platform.

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

  • You have configured an account with the cloud platform that hosts your cluster.

  • You have the OKD 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.

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.

Installing the OpenShift CLI

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.

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OKD 4.16. Download and install the new version of oc.

Installing the OpenShift CLI on Linux

You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.

Procedure

  1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

  2. Download oc.tar.gz.

  3. Unpack the archive:

    $ tar xvf <file>

  4. Place the oc binary in a directory that is on your PATH.

    To check your PATH, execute the following command:

    $ echo $PATH
Verification

  • 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

  1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

  2. Download oc.zip.

  3. Unzip the archive with a ZIP program.

  4. Move the oc binary to a directory that is on your PATH.

    To check your PATH, open the command prompt and execute the following command:

    C:\> path
Verification

  • 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

  1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

  2. Download oc.tar.gz.

  3. Unpack and unzip the archive.

  4. Move the oc binary to a directory on your PATH.

    To check your PATH, open a terminal and execute the following command:

    $ echo $PATH
Verification

  • Verify your installation by using an 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

  • You deployed an OKD 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
Additional resources
Additional resources

Next steps