Installing a cluster on vSphere with network customizations

In OKD version 4.6, you can install a cluster on VMware vSphere infrastructure that you provision 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.

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

The steps for performing a user-provisioned infrastructure installation are provided as an example only. Installing a cluster with infrastructure you provide requires knowledge of the vSphere platform and the installation process of OKD. Use the user-provisioned infrastructure installation instructions as a guide; you are free to create the required resources through other methods.

Prerequisites

VMware vSphere infrastructure requirements

You must install the OKD cluster on a VMware vSphere version 6 or 7 instance that meets the requirements for the components that you use.

Table 1. Minimum supported vSphere version for VMware components
ComponentMinimum supported versionsDescription

Hypervisor

vSphere 6.5 and later with HW version 13

This version is the minimum version that Fedora CoreOS (FCOS) supports. See the Red Hat Enterprise Linux 8 supported hypervisors list.

Storage with in-tree drivers

vSphere 6.5 and later

This plug-in creates vSphere storage by using the in-tree storage drivers for vSphere included in OKD.

Optional: Networking (NSX-T)

vSphere 6.5U3 or vSphere 6.7U2 and later

vSphere 6.5U3 or vSphere 6.7U2+ are required for OKD. VMware’s NSX Container Plug-in (NCP) 3.0.2 is certified with OKD 4.6 and NSX-T 3.x+.

If you use a vSphere version 6.5 instance, consider upgrading to 6.7U3 or 7.0 before you install OKD.

You must ensure that the time on your ESXi hosts is synchronized before you install OKD. See Edit Time Configuration for a Host in the VMware documentation.

Machine requirements for a cluster with user-provisioned infrastructure

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

Required machines

The smallest OKD clusters require the following hosts:

  • One temporary bootstrap machine

  • Three control plane, or master, machines

  • At least two compute machines, which are also known as worker machines.

The cluster requires the bootstrap machine to deploy the OKD cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

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

The bootstrap and control plane machines must use Fedora CoreOS (FCOS) as the operating system. However, the compute machines can choose between Fedora CoreOS (FCOS) or Fedora 7.9.

See Red Hat Enterprise Linux technology capabilities and limits.

All virtual machines must reside in the same datastore and in the same folder as the installer.

Network connectivity requirements

All the Fedora CoreOS (FCOS) machines require network in initramfs during boot to fetch Ignition config files from the Machine Config Server. During the initial boot, the machines require either a DHCP server or that static IP addresses be set in order to establish a network connection to download their Ignition config files. Additionally, each OKD node in the cluster must have access to a Network Time Protocol (NTP) server. If a DHCP server provides NTP servers information, the chrony time service on the Fedora CoreOS (FCOS) machines read the information and can sync the clock with the NTP servers.

Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

MachineOperating SystemvCPU [1]Virtual RAMStorageIOPS [2]

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

  1. One vCPU is equivalent to one physical core when simultaneous multithreading (SMT), or hyperthreading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.

  2. OKD and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.

Certificate signing requests management

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

Creating the user-provisioned infrastructure

Before you deploy an OKD cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Procedure

  1. Configure DHCP or set static IP addresses on each node.

  2. Provision the required load balancers.

  3. Configure the ports for your machines.

  4. Configure DNS.

  5. Ensure network connectivity.

Networking requirements for user-provisioned infrastructure

All the Fedora CoreOS (FCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

During the initial boot, the machines require either a DHCP server or that static IP addresses be set on each host in the cluster in order to establish a network connection, which allows them to download their Ignition config files.

It is recommended to use the DHCP server to manage the machines for the cluster long-term. Ensure that the DHCP server is configured to provide persistent IP addresses and host names to the cluster machines.

The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 2. All machines to all machines
ProtocolPortDescription

ICMP

N/A

Network reachability tests

TCP

1936

Metrics

9000-9999

Host level services, including the node exporter on ports 9100-9101 and the Cluster Version Operator on port 9099.

10250-10259

The default ports that Kubernetes reserves

10256

openshift-sdn

UDP

4789

VXLAN and Geneve

6081

VXLAN and Geneve

9000-9999

Host level services, including the node exporter on ports 9100-9101.

TCP/UDP

30000-32767

Kubernetes node port

Table 3. All machines to control plane
ProtocolPortDescription

TCP

6443

Kubernetes API

Table 4. Control plane machines to control plane machines
ProtocolPortDescription

TCP

2379-2380

etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

OKD requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Load balancers

Before you install OKD, you must provision two load balancers that meet the following requirements:

  1. API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.

    • A stateless load balancing algorithm. The options vary based on the load balancer implementation.

    Do not configure session persistence for an API load balancer.

    Configure the following ports on both the front and back of the load balancers:

    Table 5. API load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    6443

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the /readyz endpoint for the API server health check probe.

    X

    X

    Kubernetes API server

    22623

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.

    X

    Machine config server

    The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the /readyz endpoint to the removal of the API server instance from the pool. Within the time frame after /readyz returns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values.

  2. Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.

    • A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.

    Configure the following ports on both the front and back of the load balancers:

    Table 6. Application Ingress load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    443

    The machines that run the Ingress router pods, compute, or worker, by default.

    X

    X

    HTTPS traffic

    80

    The machines that run the Ingress router pods, compute, or worker, by default.

    X

    X

    HTTP traffic

If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

A working configuration for the Ingress router is required for an OKD cluster. You must configure the Ingress router after the control plane initializes.

Ethernet adaptor hardware address requirements

When provisioning VMs for the cluster, the ethernet interfaces configured for each VM must use a MAC address from the VMware Organizationally Unique Identifier (OUI) allocation ranges:

  • 00:05:69:00:00:00 to 00:05:69:FF:FF:FF

  • 00:0c:29:00:00:00 to 00:0c:29:FF:FF:FF

  • 00:1c:14:00:00:00 to 00:1c:14:FF:FF:FF

  • 00:50:56:00:00:00 to 00:50:56:FF:FF:FF

If a MAC address outside the VMware OUI is used, the cluster installation will not succeed.

NTP configuration

OKD clusters are configured to use a public Network Time Protocol (NTP) server by default. If you want to use a local enterprise NTP server, or if your cluster is being deployed in a disconnected network, you can configure the cluster to use a specific time server. For more information, see the documentation for Configuring chrony time service.

If a DHCP server provides NTP server information, the chrony time service on the Fedora CoreOS (FCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

User-provisioned DNS requirements

DNS is used for name resolution and reverse name resolution. DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Fedora CoreOS (FCOS) uses the reverse records to set the host name for all the nodes. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OKD needs to operate.

The following DNS records are required for an OKD cluster that uses user-provisioned infrastructure. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 7. Required DNS records
ComponentRecordDescription

Kubernetes API

api.<cluster_name>.<base_domain>.

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

api-int.<cluster_name>.<base_domain>.

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster.

The API server must be able to resolve the worker nodes by the host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

*.apps.<cluster_name>.<base_domain>.

Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

Bootstrap

bootstrap.<cluster_name>.<base_domain>.

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.

Master hosts

<master><n>.<cluster_name>.<base_domain>.

DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes (also known as the master nodes). These records must be resolvable by the nodes within the cluster.

Worker hosts

<worker><n>.<cluster_name>.<base_domain>.

Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

The following example of a BIND zone file shows sample A records for name resolution. The purpose of the example is to show the records that are needed. The example is not meant to provide advice for choosing one name resolution service over another.

Sample DNS zone database

  1. $TTL 1W
  2. @ IN SOA ns1.example.com. root (
  3. 2019070700 ; serial
  4. 3H ; refresh (3 hours)
  5. 30M ; retry (30 minutes)
  6. 2W ; expiry (2 weeks)
  7. 1W ) ; minimum (1 week)
  8. IN NS ns1.example.com.
  9. IN MX 10 smtp.example.com.
  10. ;
  11. ;
  12. ns1 IN A 192.168.1.5
  13. smtp IN A 192.168.1.5
  14. ;
  15. helper IN A 192.168.1.5
  16. helper.ocp4 IN A 192.168.1.5
  17. ;
  18. ; The api identifies the IP of your load balancer.
  19. api.ocp4 IN A 192.168.1.5
  20. api-int.ocp4 IN A 192.168.1.5
  21. ;
  22. ; The wildcard also identifies the load balancer.
  23. *.apps.ocp4 IN A 192.168.1.5
  24. ;
  25. ; Create an entry for the bootstrap host.
  26. bootstrap.ocp4 IN A 192.168.1.96
  27. ;
  28. ; Create entries for the master hosts.
  29. master0.ocp4 IN A 192.168.1.97
  30. master1.ocp4 IN A 192.168.1.98
  31. master2.ocp4 IN A 192.168.1.99
  32. ;
  33. ; Create entries for the worker hosts.
  34. worker0.ocp4 IN A 192.168.1.11
  35. worker1.ocp4 IN A 192.168.1.7
  36. ;
  37. ;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Sample DNS zone database for reverse records

  1. $TTL 1W
  2. @ IN SOA ns1.example.com. root (
  3. 2019070700 ; serial
  4. 3H ; refresh (3 hours)
  5. 30M ; retry (30 minutes)
  6. 2W ; expiry (2 weeks)
  7. 1W ) ; minimum (1 week)
  8. IN NS ns1.example.com.
  9. ;
  10. ; The syntax is "last octet" and the host must have an FQDN
  11. ; with a trailing dot.
  12. 97 IN PTR master0.ocp4.example.com.
  13. 98 IN PTR master1.ocp4.example.com.
  14. 99 IN PTR master2.ocp4.example.com.
  15. ;
  16. 96 IN PTR bootstrap.ocp4.example.com.
  17. ;
  18. 5 IN PTR api.ocp4.example.com.
  19. 5 IN PTR api-int.ocp4.example.com.
  20. ;
  21. 11 IN PTR worker0.ocp4.example.com.
  22. 7 IN PTR worker1.ocp4.example.com.
  23. ;
  24. ;EOF

Generating an SSH private key and adding it to the agent

If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent and the installation program. You can use this key to access the bootstrap machine in a public cluster to troubleshoot installation issues.

In a production environment, you require disaster recovery and debugging.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

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 SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:

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

    Running this command generates an SSH key that does not require a password in the location that you specified.

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

  2. Start the ssh-agent process as a background task:

    1. $ eval "$(ssh-agent -s)"

    Example output

    1. 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.

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

    1. $ ssh-add <path>/<file_name> (1)

    Example output

    1. Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
    1Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

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 a local computer.

Prerequisites

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

Procedure

  1. Download installer from https://github.com/openshift/okd/releases

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

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

  2. Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:

    1. $ tar xvf openshift-install-linux.tar.gz
  3. From the Pull Secret page on the Red Hat OpenShift Cluster Manager site, download your installation pull secret as a .txt file. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OKD components.

    Using a pull secret from the Red Hat OpenShift Cluster Manager site is not required. You can use a pull secret for another private registry. Or, if you do not need the cluster to pull images from a private registry, you can use {"auths":{"fake":{"auth":"aWQ6cGFzcwo="}}} as the pull secret when prompted during the installation.

    If you do not use the pull secret from the Red Hat OpenShift Cluster Manager site:

    • Red Hat Operators are not available.

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

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

Manually creating the installation configuration file

For installations of OKD that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

  • Obtain the OKD installation program and the access token for your cluster.

Procedure

  1. Create an installation directory to store your required installation assets in:

    1. $ mkdir <installation_directory>

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

  2. Customize the following install-config.yaml file template and save it in the <installation_directory>.

    You must name this configuration file install-config.yaml.

  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 next step of the installation process. You must back it up now.

Sample install-config.yaml file for VMware vSphere

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.

  1. apiVersion: v1
  2. baseDomain: example.com (1)
  3. compute:
  4. - hyperthreading: Enabled (2) (3)
  5. name: worker
  6. replicas: 0 (4)
  7. controlPlane:
  8. hyperthreading: Enabled (2) (3)
  9. name: master
  10. replicas: 3 (5)
  11. metadata:
  12. name: test (6)
  13. platform:
  14. vsphere:
  15. vcenter: your.vcenter.server (7)
  16. username: username (8)
  17. password: password (9)
  18. datacenter: datacenter (10)
  19. defaultDatastore: datastore (11)
  20. folder: "/<datacenter_name>/vm/<folder_name>/<subfolder_name>" (12)
  21. pullSecret: '{"auths": ...}' (13)
  22. sshKey: 'ssh-ed25519 AAAA...' (14)
1The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2The 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. Although both sections currently define a single machine pool, it is possible that future versions of OKD will support defining multiple compute pools during installation. Only one control plane pool is used.
3Whether to enable or disable simultaneous multithreading, or hyperthreading. 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. Your machines must use at least 8 CPUs and 32 GB of RAM if you disable simultaneous multithreading.

4You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OKD.
5The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
6The cluster name that you specified in your DNS records.
7The fully-qualified hostname or IP address of the vCenter server.
8The name of the user for accessing the server. This user must have at least the roles and privileges that are required for static or dynamic persistent volume provisioning in vSphere.
9The password associated with the vSphere user.
10The vSphere datacenter.
11The default vSphere datastore to use.
12Optional: For installer-provisioned infrastructure, the absolute path of an existing folder where the installation program creates the virtual machines, for example, /<datacenter_name>/vm/<folder_name>/<subfolder_name>. If you do not provide this value, the installation program creates a top-level folder in the datacenter virtual machine folder that is named with the infrastructure ID. If you are providing the infrastructure for the cluster, omit this parameter.
13The pull secret that you obtained from the Pull Secret page on the Red Hat OpenShift Cluster Manager site. 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.
14The public portion of the default SSH key for the core user in Fedora CoreOS (FCOS).

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 Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

  • If your cluster is on AWS, you added the ec2.<region>.amazonaws.com, elasticloadbalancing.<region>.amazonaws.com, and s3.<region>.amazonaws.com endpoints to your VPC endpoint. These endpoints are required to complete requests from the nodes to the AWS EC2 API. Because the proxy works on the container level, not the node level, you must route these requests to the AWS EC2 API through the AWS private network. Adding the public IP address of the EC2 API to your allowlist in your proxy server is not sufficient.

Procedure

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

    1. apiVersion: v1
    2. baseDomain: my.domain.com
    3. proxy:
    4. httpProxy: http://<username>:<pswd>@<ip>:<port> (1)
    5. httpsProxy: https://<username>:<pswd>@<ip>:<port> (2)
    6. noProxy: example.com (3)
    7. additionalTrustBundle: | (4)
    8. -----BEGIN CERTIFICATE-----
    9. <MY_TRUSTED_CA_CERT>
    10. -----END CERTIFICATE-----
    11. ...
    1A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpProxy value.
    2A proxy URL to use for creating HTTPS connections outside the cluster. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpsProxy value.
    3A comma-separated list of destination domain names, domains, IP addresses, or other network CIDRs to exclude proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass proxy for all destinations. You must include vCenter’s IP address and the IP range that you use for its machines.
    4If 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 Proxy object’s trustedCA field. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the FCOS trust bundle. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must provide the MITM CA certificate.

    The installation program does not support the proxy readinessEndpoints field.

  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.

Network configuration phases

When specifying a cluster configuration prior to installation, there are several phases in the installation procedures when you can modify the network configuration:

Phase 1

After entering the openshift-install create install-config command. In the install-config.yaml file, you can customize the following network-related fields:

  • networking.networkType

  • networking.clusterNetwork

  • networking.serviceNetwork

  • networking.machineNetwork

    For more information on these fields, refer to “Installation configuration parameters”.

    Set the networking.machineNetwork to match the CIDR that the preferred NIC resides in.

Phase 2

After entering the openshift-install create manifests command. If you must specify advanced network configuration, during this phase you can define a customized Cluster Network Operator manifest with only the fields you want to modify.

You cannot override the values specified in phase 1 in the install-config.yaml file during phase 2. However, you can further customize the cluster network provider during phase 2.

Specifying advanced network configuration

You can use advanced configuration customization to integrate your cluster into your existing network environment by specifying additional configuration for your cluster network provider. You can specify advanced network configuration only before you install the cluster.

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

  • Create the install-config.yaml file and complete any modifications to it.

  • Create the Ignition config files for your cluster.

Procedure

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

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

    where:

    <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:

    1. $ cat <<EOF > <installation_directory>/manifests/cluster-network-03-config.yml
    2. apiVersion: operator.openshift.io/v1
    3. kind: Network
    4. metadata:
    5. name: cluster
    6. spec:
    7. EOF

    where:

    <installation_directory>

    Specifies the directory name that contains the manifests/ directory for your cluster.

  3. Open the cluster-network-03-config.yml file in an editor and specify the advanced network configuration for your cluster, such as in the following example:

    Specify a different VXLAN port for the OpenShift SDN network provider

    1. apiVersion: operator.openshift.io/v1
    2. kind: Network
    3. metadata:
    4. name: cluster
    5. spec:
    6. defaultNetwork:
    7. openshiftSDNConfig:
    8. vxlanPort: 4800
  4. Save the cluster-network-03-config.yml file and quit the text editor.

  5. Optional: Back up the manifests/cluster-network-03-config.yml file. The installation program deletes the manifests/ directory when creating the cluster.

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

    1. $ 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.

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 and these fields cannot be changed:

clusterNetwork

IP address pools from which pod IP addresses are allocated.

serviceNetwork

IP address pool for services.

defaultNetwork.type

Cluster network provider, such as OpenShift SDN or OVN-Kubernetes.

You can specify the cluster network provider 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 8. Cluster Network Operator configuration object
FieldTypeDescription

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:

  1. spec:
  2. clusterNetwork:
  3. - cidr: 10.128.0.0/19
  4. hostPrefix: 23
  5. - cidr: 10.128.32.0/19
  6. hostPrefix: 23

This value is ready-only and specified in the install-config.yaml file.

spec.serviceNetwork

array

A block of IP addresses for services. The OpenShift SDN and OVN-Kubernetes Container Network Interface (CNI) network providers support only a single IP address block for the service network. For example:

  1. spec:
  2. serviceNetwork:
  3. - 172.30.0.0/14

This value is ready-only and specified in the install-config.yaml file.

spec.defaultNetwork

object

Configures the Container Network Interface (CNI) cluster network provider 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 provider, the kube-proxy configuration has no effect.

defaultNetwork object configuration

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

Table 9. defaultNetwork object
FieldTypeDescription

type

string

Either OpenShiftSDN or OVNKubernetes. The cluster network provider is selected during installation. This value cannot be changed after cluster installation.

OKD uses the OVN-Kubernetes Container Network Interface (CNI) cluster network provider by default.

openshiftSDNConfig

object

This object is only valid for the OpenShift SDN cluster network provider.

ovnKubernetesConfig

object

This object is only valid for the OVN-Kubernetes cluster network provider.

Configuration for the OpenShift SDN CNI cluster network provider

The following table describes the configuration fields for the OpenShift SDN Container Network Interface (CNI) cluster network provider.

Table 10. openshiftSDNConfig object
FieldTypeDescription

mode

string

Configures the network isolation mode for OpenShift SDN. The default value is NetworkPolicy.

The values Multitenant and Subnet are available for backwards compatibility with OKD 3.x but are not recommended. This value cannot be changed after cluster installation.

mtu

integer

The maximum transmission unit (MTU) for the VXLAN 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 expected 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 50 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 1450.

This value cannot be changed after cluster installation.

vxlanPort

integer

The port to use for all VXLAN packets. The default value is 4789. This value cannot be changed after cluster installation.

If you are running in a virtualized environment with existing nodes that are part of another VXLAN network, then you might be required to change this. For example, when running an OpenShift SDN overlay on top of VMware NSX-T, you must select an alternate port for the VXLAN, because both SDNs use the same default VXLAN port number.

On Amazon Web Services (AWS), you can select an alternate port for the VXLAN between port 9000 and port 9999.

Example OpenShift SDN configuration

  1. defaultNetwork:
  2. type: OpenShiftSDN
  3. openshiftSDNConfig:
  4. mode: NetworkPolicy
  5. mtu: 1450
  6. vxlanPort: 4789
Configuration for the OVN-Kubernetes CNI cluster network provider

The following table describes the configuration fields for the OVN-Kubernetes CNI cluster network provider.

Table 11. ovnKubernetesConfig object
FieldTypeDescription

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 expected 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.

This value cannot be changed after cluster installation.

genevePort

integer

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

Example OVN-Kubernetes configuration

  1. defaultNetwork:
  2. type: OVNKubernetes
  3. ovnKubernetesConfig:
  4. mtu: 1400
  5. genevePort: 6081

kubeProxyConfig object configuration

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

Table 12. kubeProxyConfig object
FieldTypeDescription

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:

  1. kubeProxyConfig:
  2. proxyArguments:
  3. iptables-min-sync-period:
  4. - 0s

Creating the Ignition config files

Because you must manually start the cluster machines, you must generate the Ignition config files that the cluster needs to make its machines.

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.

Prerequisites

  • Obtain the OKD installation program and the pull secret for your cluster.

Procedure

  • Obtain the Ignition config files:

    1. $ ./openshift-install create ignition-configs --dir=<installation_directory> (1)
    1For <installation_directory>, specify the directory name to store the files that the installation program creates.

    If you created an install-config.yaml file, specify the directory that contains it. Otherwise, specify an empty directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OKD version.

    The following files are generated in the directory:

    1. .
    2. ├── auth
    3. ├── kubeadmin-password
    4. └── kubeconfig
    5. ├── bootstrap.ign
    6. ├── master.ign
    7. ├── metadata.json
    8. └── worker.ign

Extracting the infrastructure name

The Ignition config files contain a unique cluster identifier that you can use to uniquely identify your cluster in VMware vSphere. If you plan to use the cluster identifier as the name of your virtual machine folder, you must extract it.

Prerequisites

  • You obtained the OKD installation program and the pull secret for your cluster.

  • You generated the Ignition config files for your cluster.

  • You installed the jq package.

Procedure

  • To extract and view the infrastructure name from the Ignition config file metadata, run the following command:

    1. $ jq -r .infraID <installation_directory>/metadata.json (1)
    1For <installation_directory>, specify the path to the directory that you stored the installation files in.

    Example output

    1. openshift-vw9j6 (1)
    1The output of this command is your cluster name and a random string.

Creating Fedora CoreOS (FCOS) machines in vSphere

Before you install a cluster that contains user-provisioned infrastructure on VMware vSphere, you must create FCOS machines on vSphere hosts for it to use.

Prerequisites

  • Obtain the Ignition config files for your cluster.

  • Create a vSphere cluster.

Procedure

  1. Convert the control plane, compute, and bootstrap Ignition config files to Base64 encoding.

    For example, if you use a Linux operating system, you can use the base64 command to encode the files.

    1. $ base64 -w0 <installation_directory>/master.ign > <installation_directory>/master.64
    1. $ base64 -w0 <installation_directory>/worker.ign > <installation_directory>/worker.64
    1. $ base64 -w0 <installation_directory>/bootstrap.ign > <installation_directory>/bootstrap.64

    If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  2. Obtain the FCOS images from the FCOS Downloads page

  3. In the vSphere Client, create a folder in your datacenter to store your VMs.

    1. Click the VMs and Templates view.

    2. Right-click the name of your datacenter.

    3. Click New FolderNew VM and Template Folder.

    4. In the window that is displayed, enter the folder name. If you did not specify an existing folder in the install-config.yaml file, then create a folder with the same name as the infrastructure ID. You use this folder name so vCenter dynamically provisions storage in the appropriate location for its Workspace configuration.

  4. In the vSphere Client, create a template for the OVA image and then clone the template as needed.

    In the following steps, you create a template and then clone the template for all of your cluster machines. You then provide the location for the Ignition config file for that cloned machine type when you provision the VMs.

    1. From the Hosts and Clusters tab, right-click your cluster name and select Deploy OVF Template.

    2. On the Select an OVF tab, specify the name of the FCOS OVA file that you downloaded.

    3. On the Select a name and folder tab, set a Virtual machine name for your template, such as Template-FCOS. Click the name of your vSphere cluster and select the folder you created in the previous step.

    4. On the Select a compute resource tab, click the name of your vSphere cluster.

    5. On the Select storage tab, configure the storage options for your VM.

      • Select Thin Provision or Thick Provision, based on your storage preferences.

      • Select the datastore that you specified in your install-config.yaml file.

    6. On the Select network tab, specify the network that you configured for the cluster, if available.

    7. When creating the OVF template, do not specify values on the Customize template tab or configure the template any further.

      Do not start the original VM template. The VM template must remain off and must be cloned for new FCOS machines. Starting the VM template configures the VM template as a VM on the platform, which prevents it from being used as a template that machine sets can apply configurations to.

  5. After the template deploys, deploy a VM for a machine in the cluster.

    1. Right-click the template name and click CloneClone to Virtual Machine.

    2. On the Select a name and folder tab, specify a name for the VM. You might include the machine type in the name, such as control-plane-0 or compute-1.

    3. On the Select a name and folder tab, select the name of the folder that you created for the cluster.

    4. On the Select a compute resource tab, select the name of a host in your datacenter.

      For a bootstrap machine, specify the URL of the bootstrap Ignition config file that you hosted.

    5. Optional: On the Select storage tab, customize the storage options.

    6. On the Select clone options, select Customize this virtual machine’s hardware.

    7. On the Customize hardware tab, click VM OptionsAdvanced.

      • Optional: Override default DHCP networking in vSphere. To enable static IP networking:

        1. Set your static IP configuration:

          1. $ export IPCFG="ip=<ip>::<gateway>:<netmask>:<hostname>:<iface>:none nameserver=srv1 [nameserver=srv2 [nameserver=srv3 [...]]]"

          Example command

          1. $ export IPCFG="ip=192.168.100.101::192.168.100.254:255.255.255.0:::none nameserver=8.8.8.8"
        2. Set the guestinfo.afterburn.initrd.network-kargs property before booting a VM from an OVA in vSphere:

          1. $ govc vm.change -vm "<vm_name>" -e "guestinfo.afterburn.initrd.network-kargs=${IPCFG}"
      • Optional: In the event of cluster performance issues, from the Latency Sensitivity list, select High.

      • Click Edit Configuration, and on the Configuration Parameters window, click Add Configuration Params. Define the following parameter names and values:

        • guestinfo.ignition.config.data: Paste the contents of the base64-encoded Ignition config file for this machine type. Note for the bootstrap node, the Ignition config file must be provided in guestinfo.ignition.config.data in the Configuration Parameters window. This is due to a restriction in the maximum size of data that can be provided in a vApp property.

        • guestinfo.ignition.config.data.encoding: Specify base64.

        • disk.EnableUUID: Specify TRUE.

      • Alternatively, prior to powering on the virtual machine, use vApp properties to:

        • Navigate to a virtual machine from the vCenter Server inventory.

        • On the Configure tab, expand Settings and select vApp options.

        • Scroll down and under Properties, apply the configurations that you just edited.

  1. 8. In the **Virtual Hardware** panel of the **Customize hardware** tab, modify the specified values as required. Ensure that the amount of RAM, CPU, and disk storage meets the minimum requirements for the machine type.
  2. 9. Complete the configuration and power on the VM.
  1. Create the rest of the machines for your cluster by following the preceding steps for each machine.

    You must create the bootstrap and control plane machines at this time. Because some pods are deployed on compute machines by default, also create at least two compute machines before you install the cluster.

Creating more Fedora CoreOS (FCOS) machines in vSphere

You can create more compute machines for your cluster that uses user-provisioned infrastructure on VMware vSphere.

Prerequisites

  • Obtain the base64-encoded Ignition file for your compute machines.

  • You have access to the vSphere template that you created for your cluster.

Procedure

  1. After the template deploys, deploy a VM for a machine in the cluster.

    1. Right-click the template’s name and click CloneClone to Virtual Machine.

    2. On the Select a name and folder tab, specify a name for the VM. You might include the machine type in the name, such as compute-1.

    3. On the Select a name and folder tab, select the name of the folder that you created for the cluster.

    4. On the Select a compute resource tab, select the name of a host in your datacenter.

    5. Optional: On the Select storage tab, customize the storage options.

    6. On the Select clone options, select Customize this virtual machine’s hardware.

    7. On the Customize hardware tab, click VM OptionsAdvanced.

      • From the Latency Sensitivity list, select High.

      • Click Edit Configuration, and on the Configuration Parameters window, click Add Configuration Params. Define the following parameter names and values:

        • guestinfo.ignition.config.data: Paste the contents of the base64-encoded compute Ignition config file for this machine type.

        • guestinfo.ignition.config.data.encoding: Specify base64.

        • disk.EnableUUID: Specify TRUE.

  1. 8. In the **Virtual Hardware** panel of the **Customize hardware** tab, modify the specified values as required. Ensure that the amount of RAM, CPU, and disk storage meets the minimum requirements for the machine type. Also, make sure to select the correct network under **Add network adapter** if there are multiple networks available.
  2. 9. Complete the configuration and power on the VM.
  1. Continue to create more compute machines for your cluster.

Disk partitioning

In most cases, data partitions are originally created by installing FCOS, rather than by installing another operating system. In such cases, the OKD installer should be allowed to configure your disk partitions.

However, there are two cases where you might want to intervene to override the default partitioning when installing an OKD node:

  • Create separate partitions: For greenfield installations on an empty disk, you might want to add separate storage to a partition. This is officially supported for making /var or a subdirectory of /var, such as /var/lib/etcd, a separate partition, but not both.

    Kubernetes supports only two filesystem partitions. If you add more than one partition to the original configuration, Kubernetes cannot monitor all of them.

  • Retain existing partitions: For a brownfield installation where you are reinstalling OKD on an existing node and want to retain data partitions installed from your previous operating system, there are both boot arguments and options to coreos-installer that allow you to retain existing data partitions.

Creating a separate /var partition

In general, disk partitioning for OKD should be left to the installer. However, there are cases where you might want to create separate partitions in a part of the filesystem that you expect to grow.

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

  • /var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system.

  • /var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage.

  • /var: Holds data that you might want to keep separate for purposes such as auditing.

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

Because /var must be in place before a fresh installation of Fedora CoreOS (FCOS), the following procedure sets up the separate /var partition by creating a machine config that is inserted during the openshift-install preparation phases of an OKD installation.

Prerequisites

  • If container storage is on the root partition, ensure that this root partition is mounted with the pquota option by including rootflags=pquota in the GRUB command line.

  • If the container storage is on a partition that is mounted by /etc/fstab, ensure that the following mount option is included in the /etc/fstab file:

    1. /dev/sdb1 /var xfs defaults,pquota 0 0
  • If the container storage is on a partition that is mounted by systemd, ensure that the MachineConfig object includes the following mount option as in this example:

    1. spec:
    2. config:
    3. ignition:
    4. version: 3.1.0
    5. storage:
    6. disks:
    7. - device: /dev/sdb
    8. partitions:
    9. - label: var
    10. sizeMiB: 240000
    11. startMiB: 0
    12. filesystems:
    13. - device: /dev/disk/by-partlabel/var
    14. format: xfs
    15. path: /var
    16. systemd:
    17. units:
    18. - contents: |
    19. [Unit]
    20. Before=local-fs.target
    21. [Mount]
    22. Where=/var
    23. What=/dev/disk/by-partlabel/var
    24. Options=defaults,pquota
    25. [Install]
    26. WantedBy=local-fs.target
    27. enabled: true
    28. name: var.mount

Procedure

  1. Create a directory to hold the OKD installation files:

    1. $ mkdir $HOME/clusterconfig
  2. Run openshift-install to create a set of files in the manifest and openshift subdirectories. Answer the system questions as you are prompted:

    1. $ openshift-install create manifests --dir $HOME/clusterconfig
    2. ? SSH Public Key ...
    3. $ ls $HOME/clusterconfig/openshift/
    4. 99_kubeadmin-password-secret.yaml
    5. 99_openshift-cluster-api_master-machines-0.yaml
    6. 99_openshift-cluster-api_master-machines-1.yaml
    7. 99_openshift-cluster-api_master-machines-2.yaml
    8. ...
  3. Create a MachineConfig object and add it to a file in the openshift directory. For example, name the file 98-var-partition.yaml, change the disk device name to the name of the storage device on the worker systems, and set the storage size as appropriate. This attaches storage to a separate /var directory.

    1. apiVersion: machineconfiguration.openshift.io/v1
    2. kind: MachineConfig
    3. metadata:
    4. labels:
    5. machineconfiguration.openshift.io/role: worker
    6. name: 98-var-partition
    7. spec:
    8. config:
    9. ignition:
    10. version: 3.1.0
    11. storage:
    12. disks:
    13. - device: /dev/<device_name> (1)
    14. partitions:
    15. - sizeMiB: <partition_size>
    16. startMiB: <partition_start_offset> (2)
    17. label: var
    18. filesystems:
    19. - path: /var
    20. device: /dev/disk/by-partlabel/var
    21. format: xfs
    22. systemd:
    23. units:
    24. - name: var.mount
    25. enabled: true
    26. contents: |
    27. [Unit]
    28. Before=local-fs.target
    29. [Mount]
    30. Where=/var
    31. What=/dev/disk/by-partlabel/var
    32. [Install]
    33. WantedBy=local-fs.target
    1The storage device name of the disk that you want to partition.
    2When adding a data partition to the boot disk, a minimum value of 25000 mebibytes is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of FCOS might overwrite the beginning of the data partition.
  4. Run openshift-install again to create Ignition configs from a set of files in the manifest and openshift subdirectories:

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

Now you can use the Ignition config files as input to the vSphere installation procedures to install Fedora CoreOS (FCOS) systems.

Creating the cluster

To create the OKD cluster, you wait for the bootstrap process to complete on the machines that you provisioned by using the Ignition config files that you generated with the installation program.

Prerequisites

  • Create the required infrastructure for the cluster.

  • You obtained the installation program and generated the Ignition config files for your cluster.

  • You used the Ignition config files to create FCOS machines for your cluster.

  • Your machines have direct Internet access or have an HTTP or HTTPS proxy available.

Procedure

  1. Monitor the bootstrap process:

    1. $ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ (1)
    2. --log-level=info (2)
    1For <installation_directory>, specify the path to the directory that you stored the installation files in.
    2To view different installation details, specify warn, debug, or error instead of info.

    Example output

    1. INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
    2. INFO API v1.19.0 up
    3. INFO Waiting up to 30m0s for bootstrapping to complete...
    4. INFO It is now safe to remove the bootstrap resources

    The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.

  2. After bootstrap process is complete, remove the bootstrap machine from the load balancer.

    You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the machine itself.

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:

    1. $ export KUBECONFIG=<installation_directory>/auth/kubeconfig (1)
    1For <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:

    1. $ oc whoami

    Example output

    1. system:admin

Approving the certificate signing requests for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.

Prerequisites

  • You added machines to your cluster.

Procedure

  1. Confirm that the cluster recognizes the machines:

    1. $ oc get nodes

    Example output

    1. NAME STATUS ROLES AGE VERSION
    2. master-0 Ready master 63m v1.19.0
    3. master-1 Ready master 63m v1.19.0
    4. master-2 Ready master 64m v1.19.0
    5. worker-0 NotReady worker 76s v1.19.0
    6. worker-1 NotReady worker 70s v1.19.0

    The output lists all of the machines that you created.

    The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.

  2. Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

    1. $ oc get csr

    Example output

    1. NAME AGE REQUESTOR CONDITION
    2. csr-8b2br 15m system:serviceaccount:openshift-machine-config-operator:node-bootstrapper Pending
    3. csr-8vnps 15m system:serviceaccount:openshift-machine-config-operator:node-bootstrapper Pending
    4. ...

    In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

  3. If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:

    Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. Once the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.

    For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the oc exec, oc rsh, and oc logs commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the node-bootstrapper service account in the system:node or system:admin groups, and confirm the identity of the node.

    • To approve them individually, run the following command for each valid CSR:

      1. $ oc adm certificate approve <csr_name> (1)
      1<csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      1. $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve

      Some Operators might not become available until some CSRs are approved.

  4. Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

    1. $ oc get csr

    Example output

    1. NAME AGE REQUESTOR CONDITION
    2. csr-bfd72 5m26s system:node:ip-10-0-50-126.us-east-2.compute.internal Pending
    3. csr-c57lv 5m26s system:node:ip-10-0-95-157.us-east-2.compute.internal Pending
    4. ...
  5. If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:

    • To approve them individually, run the following command for each valid CSR:

      1. $ oc adm certificate approve <csr_name> (1)
      1<csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      1. $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
  6. After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

    1. $ oc get nodes

    Example output

    1. NAME STATUS ROLES AGE VERSION
    2. master-0 Ready master 73m v1.20.0
    3. master-1 Ready master 73m v1.20.0
    4. master-2 Ready master 74m v1.20.0
    5. worker-0 Ready worker 11m v1.20.0
    6. worker-1 Ready worker 11m v1.20.0

    It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

  • Your control plane has initialized.

Procedure

  1. Watch the cluster components come online:

    1. $ watch -n5 oc get clusteroperators

    Example output

    1. NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE
    2. authentication 4.6.0 True False False 3h56m
    3. cloud-credential 4.6.0 True False False 29h
    4. cluster-autoscaler 4.6.0 True False False 29h
    5. config-operator 4.6.0 True False False 6h39m
    6. console 4.6.0 True False False 3h59m
    7. csi-snapshot-controller 4.6.0 True False False 4h12m
    8. dns 4.6.0 True False False 4h15m
    9. etcd 4.6.0 True False False 29h
    10. image-registry 4.6.0 True False False 3h59m
    11. ingress 4.6.0 True False False 4h30m
    12. insights 4.6.0 True False False 29h
    13. kube-apiserver 4.6.0 True False False 29h
    14. kube-controller-manager 4.6.0 True False False 29h
    15. kube-scheduler 4.6.0 True False False 29h
    16. kube-storage-version-migrator 4.6.0 True False False 4h2m
    17. machine-api 4.6.0 True False False 29h
    18. machine-approver 4.6.0 True False False 6h34m
    19. machine-config 4.6.0 True False False 3h56m
    20. marketplace 4.6.0 True False False 4h2m
    21. monitoring 4.6.0 True False False 6h31m
    22. network 4.6.0 True False False 29h
    23. node-tuning 4.6.0 True False False 4h30m
    24. openshift-apiserver 4.6.0 True False False 3h56m
    25. openshift-controller-manager 4.6.0 True False False 4h36m
    26. openshift-samples 4.6.0 True False False 4h30m
    27. operator-lifecycle-manager 4.6.0 True False False 29h
    28. operator-lifecycle-manager-catalog 4.6.0 True False False 29h
    29. operator-lifecycle-manager-packageserver 4.6.0 True False False 3h59m
    30. service-ca 4.6.0 True False False 29h
    31. storage 4.6.0 True False False 4h30m
  2. Configure the Operators that are not available.

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.

The Prometheus console provides an ImageRegistryRemoved alert, for example:

“Image Registry has been removed. ImageStreamTags, BuildConfigs and DeploymentConfigs which reference ImageStreamTags may not work as expected. Please configure storage and update the config to Managed state by editing configs.imageregistry.operator.openshift.io.”

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 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. 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:

    1. $ 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:

      1. kind: PersistentVolumeClaim
      2. apiVersion: v1
      3. metadata:
      4. name: image-registry-storage (1)
      5. namespace: openshift-image-registry (2)
      6. spec:
      7. accessModes:
      8. - ReadWriteOnce (3)
      9. resources:
      10. requests:
      11. storage: 100Gi (4)
      1A unique name that represents the PersistentVolumeClaim object.
      2The namespace for the PersistentVolumeClaim object, which is openshift-image-registry.
      3The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node.
      4The size of the persistent volume claim.
    2. Create the PersistentVolumeClaim object from the file:

      1. $ oc create -f pvc.yaml -n openshift-image-registry
  3. Edit the registry configuration so that it references the correct PVC:

    1. $ oc edit config.imageregistry.operator.openshift.io -o yaml

    Example output

    1. storage:
    2. pvc:
    3. claim: (1)
    1Creating a custom PVC allows you to 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.

Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

  • Your control plane has initialized.

  • You have completed the initial Operator configuration.

Procedure

  1. Confirm that all the cluster components are online with the following command:

    1. $ watch -n5 oc get clusteroperators

    Example output

    1. NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE
    2. authentication 4.6.0 True False False 3h56m
    3. cloud-credential 4.6.0 True False False 29h
    4. cluster-autoscaler 4.6.0 True False False 29h
    5. config-operator 4.6.0 True False False 6h39m
    6. console 4.6.0 True False False 3h59m
    7. csi-snapshot-controller 4.6.0 True False False 4h12m
    8. dns 4.6.0 True False False 4h15m
    9. etcd 4.6.0 True False False 29h
    10. image-registry 4.6.0 True False False 3h59m
    11. ingress 4.6.0 True False False 4h30m
    12. insights 4.6.0 True False False 29h
    13. kube-apiserver 4.6.0 True False False 29h
    14. kube-controller-manager 4.6.0 True False False 29h
    15. kube-scheduler 4.6.0 True False False 29h
    16. kube-storage-version-migrator 4.6.0 True False False 4h2m
    17. machine-api 4.6.0 True False False 29h
    18. machine-approver 4.6.0 True False False 6h34m
    19. machine-config 4.6.0 True False False 3h56m
    20. marketplace 4.6.0 True False False 4h2m
    21. monitoring 4.6.0 True False False 6h31m
    22. network 4.6.0 True False False 29h
    23. node-tuning 4.6.0 True False False 4h30m
    24. openshift-apiserver 4.6.0 True False False 3h56m
    25. openshift-controller-manager 4.6.0 True False False 4h36m
    26. openshift-samples 4.6.0 True False False 4h30m
    27. operator-lifecycle-manager 4.6.0 True False False 29h
    28. operator-lifecycle-manager-catalog 4.6.0 True False False 29h
    29. operator-lifecycle-manager-packageserver 4.6.0 True False False 3h59m
    30. service-ca 4.6.0 True False False 29h
    31. storage 4.6.0 True False False 4h30m

    Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

    1. $ ./openshift-install --dir=<installation_directory> wait-for install-complete (1)
    1For <installation_directory>, specify the path to the directory that you stored the installation files in.

    Example output

    1. INFO Waiting up to 30m0s for the cluster to initialize...

    The command succeeds when the Cluster Version Operator finishes deploying the OKD cluster from Kubernetes API server.

    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.

  2. Confirm that the Kubernetes API server is communicating with the pods.

    1. To view a list of all pods, use the following command:

      1. $ oc get pods --all-namespaces

      Example output

      1. NAMESPACE NAME READY STATUS RESTARTS AGE
      2. openshift-apiserver-operator openshift-apiserver-operator-85cb746d55-zqhs8 1/1 Running 1 9m
      3. openshift-apiserver apiserver-67b9g 1/1 Running 0 3m
      4. openshift-apiserver apiserver-ljcmx 1/1 Running 0 1m
      5. openshift-apiserver apiserver-z25h4 1/1 Running 0 2m
      6. openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8 1/1 Running 0 5m
      7. ...
    2. View the logs for a pod that is listed in the output of the previous command by using the following command:

      1. $ oc logs <pod_name> -n <namespace> (1)
      1Specify the pod name and namespace, as shown in the output of the previous command.

      If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

You can add extra compute machines after the cluster installation is completed by following Adding compute machines to vSphere.

Backing up VMware vSphere volumes

OKD provisions new volumes as independent persistent disks to freely attach and detach the volume on any node in the cluster. As a consequence, it is not possible to back up volumes that use snapshots, or to restore volumes from snapshots. See Snapshot Limitations for more information.

Procedure

To create a backup of persistent volumes:

  1. Stop the application that is using the persistent volume.

  2. Clone the persistent volume.

  3. Restart the application.

  4. Create a backup of the cloned volume.

  5. Delete the cloned volume.

Additional resources

Next steps