In OKD version 4, you can install a cluster on bare metal infrastructure that you provision in a restricted network.

While you might be able to follow this procedure to deploy a cluster on virtualized or cloud environments, you must be aware of additional considerations for non-bare metal platforms. Review the information in the guidelines for deploying OKD on non-tested platforms before you attempt to install an OKD cluster in such an environment.

Prerequisites

  • Create a registry on your mirror host and obtain the imageContentSources data for your version of OKD.

    Because the installation media is on the mirror host, you can use that computer to complete all installation steps.

  • Provision persistent storage for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.

  • Review details about the OKD installation and update processes.

  • If you use a firewall and plan to use telemetry, you must configure the firewall to allow the sites that your cluster requires access to.

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

About installations in restricted networks

In OKD 4, you can perform an installation that does not require an active connection to the internet to obtain software components. You complete an installation in a restricted network on only infrastructure that you provision, not infrastructure that the installation program provisions, so your platform selection is limited.

If you choose to perform a restricted network installation on a cloud platform, you still require access to its cloud APIs. Some cloud functions, like Amazon Web Service’s IAM service, require internet access, so you might still require internet access. Depending on your network, you might require less internet access for an installation on bare metal hardware or on VMware vSphere.

To complete a restricted network installation, you must create a registry that mirrors the contents of the OKD registry and contains the installation media. You can create this registry on a mirror host, which can access both the internet and your closed network, or by using other methods that meet your restrictions.

Restricted network installations always use user-provisioned infrastructure. Because of the complexity of the configuration for user-provisioned installations, consider completing a standard user-provisioned infrastructure installation before you attempt a restricted network installation. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network.

Additional limits

Clusters in restricted networks have the following additional limitations and restrictions:

  • The ClusterVersion status includes an Unable to retrieve available updates error.

  • By default, you cannot use the contents of the Developer Catalog because you cannot access the required ImageStreamTags.

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, control plane, and compute machines must use the Fedora CoreOS (FCOS) as the operating system.

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.

Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

Machine Operating System vCPU Virtual RAM Storage

Bootstrap

FCOS

4

16 GB

120 GB

Control plane

FCOS

4

16 GB

120 GB

Compute

FCOS or RHEL 7.6

2

8 GB

120 GB

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.

Prerequistes
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 1. All machines to all machines
Protocol Port Description

ICMP

N/A

Network reachability tests

TCP

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 NodePort

Table 2. All machines to control plane
Protocol Port Description

TCP

2379-2380

etcd server, peer, and metrics ports

6443

Kubernetes API

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.

    Session persistence is not required for the API load balancer to function properly.

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

    Table 3. API load balancer
    Port Back-end machines (pool members) Internal External Description

    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 4. Application Ingress load balancer
    Port Back-end machines (pool members) Internal External Description

    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.

User-provisioned DNS requirements

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 5. Required DNS records
Component Record Description

Kubernetes API

api.<cluster_name>.<base_domain>.

This DNS A/AAAA or CNAME record must point to the load balancer for the control plane machines. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

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

This DNS A/AAAA or CNAME record must point to the load balancer for the control plane machines. This record 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 it cannot resolve the node names, proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

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

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

Generating 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.

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:

    $ ssh-keygen -t rsa -b 4096 -N '' \
        -f <path>/<file_name> (1)
    1 Specify the path and file name, such as ~/.ssh/id_rsa, of the new SSH key.

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

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

    $ eval "$(ssh-agent -s)"
    Example output
    Agent pid 31874
  3. Add your SSH private key to the ssh-agent:

    $ ssh-add <path>/<file_name> (1)
    Example output
    Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
    1 Specify 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. If you install a cluster on infrastructure that you provision, you must provide this key to your cluster’s machines.

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.

  • Obtain the imageContentSources section from the output of the command to mirror the repository.

  • Obtain the contents of the certificate for your mirror registry.

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

    $ 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.

    • Unless you use a registry that FCOS trusts by default, such as docker.io, you must provide the contents of the certificate for your mirror repository in the additionalTrustBundle section. In most cases, you must provide the certificate for your mirror.

    • You must include the imageContentSources section from the output of the command to mirror the repository.

  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 bare metal

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.

apiVersion: v1
baseDomain: example.com (1)
compute:
- hyperthreading: Enabled  (2) (3)
  name: worker
  replicas: 0 (4)
controlPlane:
  hyperthreading: Enabled  (2) (3)
  name: master (3)
  replicas: 3 (5)
metadata:
  name: test (6)
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 (7)
    hostPrefix: 23 (8)
  networkType: OpenShiftSDN
  serviceNetwork: (9)
  - 172.30.0.0/16
platform:
  none: {} (10)
fips: false (11)
pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' (12)
sshKey: 'ssh-ed25519 AAAA...' (13)
additionalTrustBundle: | (14)
  -----BEGIN CERTIFICATE-----
  ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
  -----END CERTIFICATE-----
imageContentSources: (15)
- mirrors:
  - <local_registry>/<local_repository_name>/release
  source: quay.io/openshift-release-dev/ocp-release
- mirrors:
  - <local_registry>/<local_repository_name>/release
  source: registry.svc.ci.openshift.org/ocp/release
1 The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. 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.
3 Whether 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.

4 You 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.
5 The 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.
6 The cluster name that you specified in your DNS records.
7 A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
8 The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.
9 The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
10 You must set the platform to none. You cannot provide additional platform configuration variables for bare metal infrastructure.
11 Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Fedora CoreOS (FCOS) machines that OKD runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with FCOS instead.
12 For <local_registry>, specify the registry domain name, and optionally the port, that your mirror registry uses to serve content. For example registry.example.com or registry.example.com:5000. For <credentials>, specify the base64-encoded user name and password for your mirror registry.
13 The 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.

14 Provide the contents of the certificate file that you used for your mirror registry.
15 Provide the imageContentSources section from the output of the command to mirror the repository.

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.

For bare metal installations, if you do not assign node IP addresses from the range that is specified in the networking.machineNetwork[].cidr field in the install-config.yaml file, you must include them in the proxy.noProxy field.

Prerequisites
  • An existing install-config.yaml file.

  • Review the sites that your cluster requires access to and determine whether any need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. Add sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.

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

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

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

    apiVersion: v1
    baseDomain: my.domain.com
    proxy:
      httpProxy: http://<username>:<pswd>@<ip>:<port> (1)
      httpsProxy: http://<username>:<pswd>@<ip>:<port> (2)
      noProxy: example.com (3)
    additionalTrustBundle: | (4)
        -----BEGIN CERTIFICATE-----
        <MY_TRUSTED_CA_CERT>
        -----END CERTIFICATE-----
    ...
    1 A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http. 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.
    2 A proxy URL to use for creating HTTPS connections outside the cluster. If this field is not specified, then httpProxy is used for both HTTP and HTTPS connections. 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.
    3 A comma-separated list of destination domain names, domains, IP addresses, or other network CIDRs to exclude proxying. Preface a domain with . to include all subdomains of that domain. Use * to bypass proxy for all destinations.
    4 If provided, the installation program generates a ConfigMap 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 ConfigMap that merges these contents with the Fedora CoreOS (FCOS) trust bundle, and this ConfigMap 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.

Configuring a three-node cluster

You can optionally install and run three-node clusters in OKD with no workers. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for development, production, and testing.

Procedure
  • Edit the install-config.yaml file to set the number of compute replicas, which are also known as worker replicas, to 0, as shown in the following compute stanza:

    compute:
    - name: worker
      platform: {}
      replicas: 0

Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to 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. For a restricted network installation, these files are on your mirror host.

  • Create the install-config.yaml installation configuration file.

Procedure
  1. Generate the Kubernetes manifests for the cluster:

    $ ./openshift-install create manifests --dir=<installation_directory> (1)
    Example output
    INFO Consuming Install Config from target directory
    WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings
    1 For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.

    Because you create your own compute machines later in the installation process, you can safely ignore this warning.

If you are running a three-node cluster, skip the following step to allow the masters to be schedulable.

  1. Modify the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file to prevent pods from being scheduled on the control plane machines:

    1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.

    2. Locate the mastersSchedulable parameter and set its value to False.

    3. Save and exit the file.

  2. Obtain the Ignition config files:

    $ ./openshift-install create ignition-configs --dir=<installation_directory> (1)
    1 For <installation_directory>, specify the same installation directory.

    The following files are generated in the directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign

Creating Fedora CoreOS (FCOS) machines

Before you install a cluster on bare metal infrastructure that you provision, you must create FCOS machines for it to use. To create the machines, follow either the steps to use an ISO image or network PXE booting.

There are several methods of configuring FCOS during ISO and PXE installations. These include:

  • Kernel arguments: For a PXE install, you can APPEND arguments to the kernel of the live installer. For an ISO install, you can interrupt the live install boot process to add kernel arguments. In both cases, you can use special coreos.inst.* arguments to direct the live installer, as well as standard installation boot arguments for turning standard kernel services on or off.

  • Ignition configs: You need to generate an OKD Ignition config file (*.ign) for the type of node you are installing (worker, control plane, or bootstrap). You pass the location of the Ignition config to the installed system so that it takes effect on first boot. In special cases, you can create a separate, limited Ignition config to pass to the live system. That Ignition config could do a certain set of tasks, such as reporting success to a provisioning system after completing installation. This special Ignition config is consumed by the installer and should not be used to include the standard worker and master Ignition configs.

  • coreos-installer: You can boot the live ISO installer to a shell prompt, which allows you to prepare the permanent system in a variety of ways before first boot. In particular, you can run the coreos-installer command to identify various artifacts to include, work with disk partitions, and set up networking. In some cases, you can configure features on the live system and copy them to the installed system.

Whether to use an ISO or PXE install depends on your situation. A PXE install requires an available DHCP service and more preparation, but can make the installation process more automated. An ISO install is a more manual process and can be inconvenient if you are setting up more than a few machines.

Creating Fedora CoreOS (FCOS) machines using an ISO image

Before you install a cluster on bare metal infrastructure that you provision, you must create FCOS machines for it to use. You can use an ISO image to create the machines.

Prerequisites
  • Obtain the Ignition config files for your cluster.

  • Have access to an HTTP server that can be accessed from your computer, and from the machines that you create.

Procedure
  1. Upload the control plane, compute, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    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. Use the ISO to start the FCOS installation. Use one of the following installation options:

    • Burn the ISO image to a disk and boot it directly.

    • Use ISO redirection via a LOM interface.

  4. Boot the ISO image. You can interrupt the installation boot process to add kernel arguments. However, for this ISO procedure you should use the coreos-installer command instead of adding kernel arguments. If you run the live installer without options or interruption, the installer boots up to a shell prompt on the live system, ready for you to install FCOS to disk.

  5. Review the “Advanced FCOS installation reference” section for different ways of configuring features, such as networking and disk partitions, before running the coreos-installer.

  6. Run the coreos-installer command. At a minimum, you must identify the Ignition config file location for your node type, and the location of the disk you are installing to. Here is an example:

    $ coreos-installer install \
         --ignition-url=https://host/worker.ign /dev/sda
  7. After FCOS installs, the system reboots. During the system reboot, it applies the Ignition config file that you specified.

  8. Continue to create the other machines for your cluster.

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

Creating Fedora CoreOS (FCOS) machines by PXE or iPXE booting

Before you install a cluster on bare metal infrastructure that you provision, you must create FCOS machines for it to use. You can use PXE or iPXE booting to create the machines.

Prerequisites
  • Obtain the Ignition config files for your cluster.

  • Configure suitable PXE or iPXE infrastructure.

  • Have access to an HTTP server that you can access from your computer.

Procedure
  1. Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  2. Obtain the FCOS kernel, initramfs and rootfs files from the FCOS Downloads page

  3. Upload the rootfs, kernel, and initramfs files to your HTTP server.

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

  4. Configure the network boot infrastructure so that the machines boot from their local disks after FCOS is installed on them.

  5. Configure PXE or iPXE installation for the FCOS images.

    Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:

    • For PXE:

      DEFAULT pxeboot
      TIMEOUT 20
      PROMPT 0
      LABEL pxeboot
          KERNEL http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> (1)
          APPEND initrd=http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign (2) (3)
      1 Specify the location of the live kernel file that you uploaded to your HTTP server. The URL must be HTTP, TFTP, or FTP; HTTPS and NFS are not supported.
      2 If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3 Specify locations of the FCOS files that you uploaded to your HTTP server. The initrd parameter value is the location of the initramfs file, the coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file. You can also add more kernel arguments to the APPEND line to configure networking or other boot options.
    • For iPXE:

      kernel  http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign (1) (2)
      initrd http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img
      boot
      1 Specify locations of the FCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd parameter value is the location of the initramfs file. The coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.
      2 If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
  6. Continue to create the machines for your cluster.

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

Advanced Fedora CoreOS (FCOS) installation configuration

A key reason for doing a bare metal installation of Fedora CoreOS (FCOS) nodes for OKD is to be able to do configuration that is not available through default OKD installation methods. This section describes some of the configurations that you can do using techniques that include:

  • Passing kernel arguments to the live installer

  • Running coreos-installer manually from the live system

  • Embedding Ignition configs in an ISO

The advanced configuration topics for bare metal Fedora CoreOS (FCOS) installations detailed in this section relate to disk partitioning, networking, and using Ignition configs in different ways.

Using advanced networking options for PXE and ISO installations

Networking for OKD nodes uses DHCP by default to gather all necessary configuration settings. To set up static IP addresses or configure special settings, such as bonding, you can do one of the following:

  • Pass special kernel parameters when you boot the live installer.

  • Use a MachineConfig to copy networking files to the installed system.

  • Configure networking from a live installer shell prompt, then copy those settings to the installed system so that they take effect when the installed system first boots.

To configure a PXE or iPXE installation, use one of the following options:

  • See the "Advanced RHCOS installation reference" tables.

  • Use a MachineConfig to copy networking files to the installed system.

To configure an ISO installation, use the following procedure.

Procedure
  1. Boot the ISO installer.

  2. From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.

  3. Run the coreos-installer command to install the system, adding the --copy-network option to copy networking configuration. For example:

    $ coreos-installer install --copy-network \
         --ignition-url=http://host/worker.ign /dev/sda
  4. Reboot into the installed system.

Disk partitioning

In most 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 only officially supported for making /var or a subdirectory of /var a separate partition, but not both. If you create more than one partition, Kubernetes will not be able to monitor them both.

  • Retain existing partitions: For a brownfield installation, where you are reinstalling on an existing OKD node and want to retain data partitions 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 a separate partition 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: 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 MachineConfig that is inserted during the openshift-install preparation phases of an OKD installation.

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

    $ 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:

    $ openshift-install create manifests --dir $HOME/clusterconfig
    ? SSH Public Key ...
    $ ls $HOME/clusterconfig/openshift/
    99_kubeadmin-password-secret.yaml
    99_openshift-cluster-api_master-machines-0.yaml
    99_openshift-cluster-api_master-machines-1.yaml
    99_openshift-cluster-api_master-machines-2.yaml
    ...
  3. Create a MachineConfig and add it to a file in the openshift directory. For example, name the file 98-var-partition.yaml, change the 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.

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker
      name: 98-var-partition
    spec:
      config:
        ignition:
          version: 3.1.0
        storage:
          disks:
          - device: /dev/<device_name> (1)
            partitions:
            - sizeMiB: <partition_size>
              startMiB: <partition_start_offset> (2)
              label: var
          filesystems:
            - path: /var
              device: /dev/disk/by-partlabel/var
              format: xfs
        systemd:
          units:
            - name: var.mount
              enabled: true
              contents: |
                [Unit]
                Before=local-fs.target
                [Mount]
                Where=/var
                What=/dev/disk/by-partlabel/var
                [Install]
                WantedBy=local-fs.target
    1 The storage device name of the disk that you want to partition.
    2 When adding a data partition to the boot disk, a minimum value of 25000 mebibytes is recommended. The root filesystem 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 filesystem 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:

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

Now you can use the Ignition config files as input to the ISO or PXE bare metal installation procedures to install Fedora CoreOS (FCOS) systems.

Retaining existing partitions

For an ISO installation, you can add options to the coreos-installer command line that causes the installer to maintain one or more existing partitions. For a PXE installation, you can APPEND coreos.inst options to preserve partitions.

Saved partitions might be partitions from an existing OKD system that has data partitions that you want to keep. Here are a few tips:

  • If you save existing partitions, and those partitions do not leave enough space for FCOS, installation will fail without damaging the saved partitions.

  • Identify the disk partitions you want to keep either by partition label or by number.

For an ISO installation

This example preserves any partition in which the partition label begins with data (data*):

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partlabel 'data*' /dev/sda

The following example illustrates running the coreos-installer in a way that preserves the sixth (6) partition on the disk:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partindex 6 /dev/sda

This example preserves partitions 5 and higher:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign
        --save-partindex 5- /dev/sda

In the previous examples where partition saving is used, coreos-installer recreates the partition immediately.

For a PXE installation

This APPEND option preserves any partition in which the partition label begins with 'data' ('data*'):

coreos.inst.save_partlabel=data*

This APPEND option preserves partitions 5 and higher:

coreos.inst.save_partindex=5-

This APPEND option preserves partition 6:

coreos.inst.save_partindex=6

Identifying Ignition configs

When doing an FCOS bare metal installation, there are two types of Ignition configs that you can provide, with different reasons for providing each one:

  • Permanent install Ignition config: Every bare metal FCOS installation needs to pass one of the Ignition config files generated by openshift-installer, such as bootstrap.ign, master.ign and worker.ign, to carry out the installation.

    It is not recommended to modify these files.

    For PXE installations, you pass the Ignition configs on the APPEND line using the coreos.inst.ignition_url= option. For ISO installations, after the ISO boots to the shell prompt, you identify the Ignition config on the coreos-installer command line with the --ignition-url= option.

  • Live install Ignition config: This type must be created manually and should be avoided if possible, as it is not supported by Red Hat. With this method, the Ignition config passes to the live install medium, runs immediately upon booting, and performs setup tasks before and/or after the FCOS system installs to disk. This method should only be used for performing tasks that must be performed once and not applied again later, such as with advanced partitioning that cannot be done using a MachineConfig.

    For PXE or ISO boots, you can create the Ignition config and APPEND the ignition.config.url= option to identify the location of the Ignition config. You also need to append ignition.firstboot ignition.platform.id=metal or the ignition.config.url option will be ignored.

Embedding an Ignition config in the FCOS ISO

You can embed a live install Ignition config directly in an FCOS ISO image. When the ISO image is booted, the embedded config will be applied automatically.

This type of configuration must be created manually and should be avoided if possible, as it is not supported by Red Hat.

Procedure
  1. Download the coreos-installer binary from the following image mirror page: https://mirror.openshift.com/pub/openshift-v4/clients/coreos-installer/latest/.

  2. Retrieve the FCOS ISO image and the Ignition config file, and copy them into an accessible directory, such as /mnt:

    # cp rhcos-<version>-live.x86_64.iso live.ign /mnt/
    # chmod 644 /mnt/rhcos-<version>-live.x86_64.iso
  3. Run the following command to embed the Ignition config into the ISO:

    # ./coreos-installer iso ignition embed -i /mnt/live.ign \
         /mnt/rhcos-<version>-live.x86_64.iso

    You can now use that ISO to install FCOS using the specified live install Ignition config.

    Using coreos-installer iso ignition embed to embed a file generated by openshift-installer, such as bootstrap.ign, master.ign and worker.ign, is unsupported and not recommended.

  4. To show the contents of the embedded Ignition config and direct it into a file, run:

    # ./coreos-installer iso ignition show /mnt/rhcos-<version>-live.x86_64.iso > mylive.ign
    # diff -s live.ign mylive.ign
    Example output
    Files live.ign and mylive.ign are identical
  5. To remove the Ignition config and return the ISO to its pristine state so you can reuse it, run:

    # ./coreos-installer iso ignition remove /mnt/rhcos-<version>-live.x86_64.iso

    You can now embed another Ignition config into the ISO or use the ISO in its pristine state.

Advanced FCOS installation reference

This section illustrates the networking configuration and other advanced options that allow you to modify the Fedora CoreOS (FCOS) bare metal install process. The following tables describe the kernel arguments and command-line options you can use with the FCOS live installer and the coreos-installer command.

Routing and bonding options at FCOS boot prompt

If you install FCOS from an ISO image, you can add kernel arguments manually when you boot that image to configure the node’s networking. If no networking arguments are used, the installation defaults to using DHCP.

When adding networking arguments, you must also add the rd.neednet=1 kernel argument.

The following table describes how to use ip=, nameserver=, and bond= kernel arguments for live ISO installs.

Table 6. Routing and bonding options for ISO
Description Examples

To configure an IP address, either use DHCP (ip=dhcp) or set an individual static IP address (ip=<host_ip>). If setting a static IP, you must then identify the DNS server IP address (nameserver=<dns_ip>) on each node. This example sets:

  • The node’s IP address to 10.10.10.2

  • The gateway address to 10.10.10.254

  • The netmask to 255.255.255.0

  • The hostname to core0.example.com

  • The DNS server address to 4.4.4.41

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
nameserver=4.4.4.41

Specify multiple network interfaces by specifying multiple ip= entries.

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none

You can combine DHCP and static IP configurations on systems with multiple network interfaces.

ip=enp1s0:dhcp
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none

You can provide multiple DNS servers by adding a nameserver= entry for each server.

nameserver=1.1.1.1
nameserver=8.8.8.8

Optional: Bonding multiple network interfaces to a single interface is supported using the bond= option. In these two examples:

  • The syntax for configuring a bonded interface is: bond=name[:network_interfaces][:options]

  • name is the bonding device name (bond0), network_interfaces represents a comma-separated list of physical (ethernet) interfaces (em1,em2), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.

  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

To configure the bonded interface to use DHCP, set the bond’s IP address to dhcp. For example:

bond=bond0:em1,em2:mode=active-backup
ip=bond0:dhcp

To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:

bond=bond0:em1,em2:mode=active-backup
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
coreos.inst boot options for ISO or PXE install

While you can pass most standard boot arguments to the live installer, there are several arguments that are specific to the FCOS live installer.

  • For ISO, these options can be added by interrupting the boot at the bootloader menu.

  • For PXE or iPXE, these options must be added to the APPEND line before starting the PXE kernel.

The following table shows the FCOS live installer boot options for ISO and PXE installs.

Table 7. coreos.inst boot options
Argument Description

coreos.inst.install_dev

Required. The block device on the system to install to. It is recommended to use the full path, such as /dev/sda, although sda is allowed.

coreos.inst.ignition_url

Optional: The URL of the Ignition config to embed into the installed system. If no URL is specified, no Ignition config is embedded. Only HTTP and HTTPS protocols are supported.

coreos.inst.save_partlabel

Optional: Comma-separated labels of partitions to preserve during the install. Glob-style wildcards are permitted. The specified partitions do not need to exist.

coreos.inst.save_partindex

Optional: Comma-separated indexes of partitions to preserve during the install. Ranges m-n are permitted, and either m or n can be omitted. The specified partitions do not need to exist.

coreos.inst.insecure

Optional: Permits the OS image that is specified by coreos.inst.image_url to be unsigned.

coreos.inst.image_url

Optional: Download and install the specified FCOS image.

  • This argument should not be used in production environments and is intended for debugging purposes only.

  • While this argument can be used to install a version of FCOS that does not match the live media, it is recommended that you instead use the media that matches the version you want to install.

  • If you are using coreos.inst.image_url, you must also use coreos.inst.insecure. This is because the bare-metal media are not GPG-signed for OKD.

coreos.inst.skip_reboot

Optional: The system will not reboot after installing. Once the install finishes, you will receive a prompt that allows you to inspect what is happening during installation. This argument should not be used in production environments and is intended for debugging purposes only.

coreos.inst.platform_id

Optional: The Ignition platform ID of the platform the FCOS image is being installed on. Default is metal. This option determines whether or not to request an Ignition config from the cloud provider, such as VMware. For example: coreos.inst.platform_id=vmware.

ignition.config.url

Optional: The URL of the Ignition config for the live boot. For example, this can be used to customize how coreos-installer is invoked, or to run code before or after the installation. This is different from coreos.inst.ignition_url, which is the Ignition config for the installed system.

coreos-installer options for ISO install

You can also install FCOS by invoking the coreos-installer command directly from the command line. The kernel arguments in the previous table provide a shortcut for automatically invoking coreos-installer at boot time, but you can pass similar arguments directly to coreos-installer when running it from a shell prompt.

The following table shows the options and subcommands you can pass to the coreos-installer command during a live install.

Table 8. coreos-installer command-line options, arguments, and subcommands

Command-line options

Option

Description

-u, --image-url <url>

Specify the image URL manually.

-i, --ignition-file <path>

Embed an Ignition config from a file.

I, --ignition-url <URL>

Embed an Ignition config from a URL.

--ignition-hash <digest>

Digest type-value of the Ignition config.

-p, --platform <name>

Override the Ignition platform ID for the installed system.

--append-karg <arg>…​

Append a default kernel argument to the installed system.

--delete-karg <arg>…​

Delete a default kernel argument from the installed system.

-n, --copy-network

Copy the network configuration from the install environment.

--network-dir <path>

For use with -n. Default is /etc/NetworkManager/system-connections/.

--save-partlabel <lx>..

Save partitions with this label glob.

--save-partindex <id>…​

Save partitions with this number or range.

--insecure

Skip signature verification.

--insecure-ignition

Allow Ignition URL without HTTPS or hash.

--architecture <name>

Target CPU architecture. Default is x86_64.

--preserve-on-error

Do not clear partition table on error.

-h, --help

Print help information.

-f, --image-file <path>

Specify a local image file manually. Used for debugging.

Command-line argument

Argument

Description

<device>

The destination device.

coreos-installer embedded Ignition commands

Command

Description

$ coreos-installer iso ignition embed <options> --ignition-file <file_path> <ISO_image>

Embed an Ignition config in an ISO image.

coreos-installer iso ignition show <options> <ISO_image>

Show the embedded Ignition config from an ISO image.

coreos-installer iso ignition remove <options> <ISO_image>

Remove the embedded Ignition config from an ISO image.

coreos-installer ISO Ignition options

Option

Description

-f, --force

Overwrite an existing Ignition config.

-i, --ignition-file <path>

The Ignition config to be used. Default is stdin.

-o, --output <path>

Write the ISO to a new output file.

-h, --help

Print help information.

coreos-installer PXE Ignition commands

Command

Description

Note that not all of these options are accepted by all subcommands.

coreos-installer pxe ignition wrap <options>

Wrap an Ignition config in an image.

coreos-installer pxe ignition unwrap <options> <image_name>

Show the wrapped Ignition config in an image.

coreos-installer PXE Ignition options

Option

Description

Note that not all of these options are accepted by all subcommands.

-i, --ignition-file <path>

The Ignition config to be used. Default is stdin.

-o, --output <path>

Write the ISO to a new output file.

-h, --help

Print help information.

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.

Procedure
  1. Monitor the bootstrap process:

    $ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ (1)
        --log-level=info (2)
    
    1 For <installation_directory>, specify the path to the directory that you stored the installation files in.
    2 To view different installation details, specify warn, debug, or error instead of info.
    Example output
    INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
    INFO API v1.19.0 up
    INFO Waiting up to 30m0s for bootstrapping to complete...
    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

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
  • Deploy an OKD cluster.

  • Install 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

Approving the CSRs 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.

Prerequisites
  • You added machines to your cluster.

Procedure
  1. Confirm that the cluster recognizes the machines:

    $ oc get nodes
    Example output
    NAME      STATUS    ROLES   AGE  VERSION
    master-0  Ready     master  63m  v1.19.0
    master-1  Ready     master  63m  v1.19.0
    master-2  Ready     master  64m  v1.19.0
    worker-0  NotReady  worker  76s  v1.19.0
    worker-1  NotReady  worker  70s  v1.19.0

    The output lists all of the machines that you created.

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

    $ oc get csr
    Example output
    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending (1)
    csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending (2)
    csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
    ...
    1 A client request CSR.
    2 A server request CSR.

    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. After you approve the initial CSRs, the subsequent node client CSRs are automatically approved by the cluster kube-controller-manager. You must implement a method of automatically approving the kubelet serving certificate requests.

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

      $ 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:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
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:

    $ watch -n5 oc get clusteroperators
    Example output
    NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.6.0   True        False         False      3h56m
    cloud-credential                           4.6.0   True        False         False      29h
    cluster-autoscaler                         4.6.0   True        False         False      29h
    config-operator                            4.6.0   True        False         False      6h39m
    console                                    4.6.0   True        False         False      3h59m
    csi-snapshot-controller                    4.6.0   True        False         False      4h12m
    dns                                        4.6.0   True        False         False      4h15m
    etcd                                       4.6.0   True        False         False      29h
    image-registry                             4.6.0   True        False         False      3h59m
    ingress                                    4.6.0   True        False         False      4h30m
    insights                                   4.6.0   True        False         False      29h
    kube-apiserver                             4.6.0   True        False         False      29h
    kube-controller-manager                    4.6.0   True        False         False      29h
    kube-scheduler                             4.6.0   True        False         False      29h
    kube-storage-version-migrator              4.6.0   True        False         False      4h2m
    machine-api                                4.6.0   True        False         False      29h
    machine-approver                           4.6.0   True        False         False      6h34m
    machine-config                             4.6.0   True        False         False      3h56m
    marketplace                                4.6.0   True        False         False      4h2m
    monitoring                                 4.6.0   True        False         False      6h31m
    network                                    4.6.0   True        False         False      29h
    node-tuning                                4.6.0   True        False         False      4h30m
    openshift-apiserver                        4.6.0   True        False         False      3h56m
    openshift-controller-manager               4.6.0   True        False         False      4h36m
    openshift-samples                          4.6.0   True        False         False      4h30m
    operator-lifecycle-manager                 4.6.0   True        False         False      29h
    operator-lifecycle-manager-catalog         4.6.0   True        False         False      29h
    operator-lifecycle-manager-packageserver   4.6.0   True        False         False      3h59m
    service-ca                                 4.6.0   True        False         False      29h
    storage                                    4.6.0   True        False         False      4h30m
  2. Configure the Operators that are not available.

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 PersistentVolume, 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.

Changing the image registry’s management state

To start the image registry, you must change the Image Registry Operator configuration’s managementState from Removed to Managed.

Procedure
  • Change managementState Image Registry Operator configuration from Removed to Managed. For example:

    $ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"managementState":"Managed"}}'

Configuring registry storage for bare metal

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites
  • Cluster administrator permissions.

  • A cluster on bare metal.

  • Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.

    OKD supports ReadWriteOnce access for image registry storage when you have only one replica. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.

  • Must have "100Gi" capacity.

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

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

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

    $ oc get pod -n openshift-image-registry

    If the storage type is emptyDIR, the replica number cannot be greater than 1.

  3. Check the registry configuration:

    $ oc edit configs.imageregistry.operator.openshift.io
    Example output
    storage:
      pvc:
        claim:

    Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.

  4. Check the clusteroperator status:

    $ oc get clusteroperator image-registry
  5. Ensure that your registry is set to managed to enable building and pushing of images.

    • Run:

      $ oc edit configs.imageregistry/cluster

      Then, change the line

      managementState: Removed

      to

      managementState: Managed

Configuring storage for the image registry in non-production clusters

You must configure storage for the image registry Operator. For non-production clusters, you can set the image registry to an empty directory. If you do so, all images are lost if you restart the registry.

Procedure
  • To set the image registry storage to an empty directory:

    $ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'

    Configure this option for only non-production clusters.

    If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:

    Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found

    Wait a few minutes and run the command again.

Configuring block registry storage for bare metal

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Block storage volumes are supported but not recommended for use with the 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 one (1) replica:

    $ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
  2. Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.

  3. Edit the registry configuration so that it references the correct PVC.

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:

    $ watch -n5 oc get clusteroperators
    Example output
    NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.6.0   True        False         False      3h56m
    cloud-credential                           4.6.0   True        False         False      29h
    cluster-autoscaler                         4.6.0   True        False         False      29h
    config-operator                            4.6.0   True        False         False      6h39m
    console                                    4.6.0   True        False         False      3h59m
    csi-snapshot-controller                    4.6.0   True        False         False      4h12m
    dns                                        4.6.0   True        False         False      4h15m
    etcd                                       4.6.0   True        False         False      29h
    image-registry                             4.6.0   True        False         False      3h59m
    ingress                                    4.6.0   True        False         False      4h30m
    insights                                   4.6.0   True        False         False      29h
    kube-apiserver                             4.6.0   True        False         False      29h
    kube-controller-manager                    4.6.0   True        False         False      29h
    kube-scheduler                             4.6.0   True        False         False      29h
    kube-storage-version-migrator              4.6.0   True        False         False      4h2m
    machine-api                                4.6.0   True        False         False      29h
    machine-approver                           4.6.0   True        False         False      6h34m
    machine-config                             4.6.0   True        False         False      3h56m
    marketplace                                4.6.0   True        False         False      4h2m
    monitoring                                 4.6.0   True        False         False      6h31m
    network                                    4.6.0   True        False         False      29h
    node-tuning                                4.6.0   True        False         False      4h30m
    openshift-apiserver                        4.6.0   True        False         False      3h56m
    openshift-controller-manager               4.6.0   True        False         False      4h36m
    openshift-samples                          4.6.0   True        False         False      4h30m
    operator-lifecycle-manager                 4.6.0   True        False         False      29h
    operator-lifecycle-manager-catalog         4.6.0   True        False         False      29h
    operator-lifecycle-manager-packageserver   4.6.0   True        False         False      3h59m
    service-ca                                 4.6.0   True        False         False      29h
    storage                                    4.6.0   True        False         False      4h30m

    When all of the cluster Operators are AVAILABLE, you can complete the installation.

  2. Monitor for cluster completion:

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

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

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

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

      $ oc logs <pod_name> -n <namespace> (1)
      1 Specify 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.

  4. Register your cluster on the Cluster registration page.

Next steps