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Prerequisites

About installations in restricted networks

In OpenShift Container Platform 4.10, you can perform an installation that does not require an active connection to the internet to obtain software components. Restricted network installations can be completed using installer-provisioned infrastructure or user-provisioned infrastructure, depending on the cloud platform to which you are installing the cluster.

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 OpenShift Container Platform 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.

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 image stream tags.

Resource guidelines for installing OpenShift Container Platform on RHOSP

To support an OpenShift Container Platform installation, your Red Hat OpenStack Platform (RHOSP) quota must meet the following requirements:

Table 1. Recommended resources for a default OpenShift Container Platform cluster on RHOSP
Resource Value

Floating IP addresses

3

Ports

15

Routers

1

Subnets

1

RAM

112 GB

vCPUs

28

Volume storage

275 GB

Instances

7

Security groups

3

Security group rules

60

Server groups

2 - plus 1 for each additional availability zone in each machine pool

A cluster might function with fewer than recommended resources, but its performance is not guaranteed.

If RHOSP object storage (Swift) is available and operated by a user account with the swiftoperator role, it is used as the default backend for the OpenShift Container Platform image registry. In this case, the volume storage requirement is 175 GB. Swift space requirements vary depending on the size of the image registry.

By default, your security group and security group rule quotas might be low. If you encounter problems, run openstack quota set --secgroups 3 --secgroup-rules 60 <project> as an administrator to increase them.

An OpenShift Container Platform deployment comprises control plane machines, compute machines, and a bootstrap machine.

Control plane and compute machines

By default, the OpenShift Container Platform installation process stands up three control plane and three compute machines.

Each machine requires:

  • An instance from the RHOSP quota

  • A port from the RHOSP quota

  • A flavor with at least 16 GB memory, 4 vCPUs, and 25 GB storage space

Compute machines host the applications that you run on OpenShift Container Platform; aim to run as many as you can.

Bootstrap machine

During installation, a bootstrap machine is temporarily provisioned to stand up the control plane. After the production control plane is ready, the bootstrap machine is deprovisioned.

The bootstrap machine requires:

  • An instance from the RHOSP quota

  • A port from the RHOSP quota

  • A flavor with at least 16 GB memory, 4 vCPUs, and 25 GB storage space

Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.10, you require access to the internet to obtain the images that are necessary to install your cluster.

You must have internet access to:

  • Access OpenShift Cluster Manager to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.

  • Access Quay.io to obtain the packages that are required to install your cluster.

  • Obtain the packages that are required to perform cluster updates.

If your cluster cannot have direct internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the required content and use it to populate a mirror registry with the installation packages. With some installation types, the environment that you install your cluster in will not require internet access. Before you update the cluster, you update the content of the mirror registry.

Enabling Swift on RHOSP

Swift is operated by a user account with the swiftoperator role. Add the role to an account before you run the installation program.

If the Red Hat OpenStack Platform (RHOSP) object storage service, commonly known as Swift, is available, OpenShift Container Platform uses it as the image registry storage. If it is unavailable, the installation program relies on the RHOSP block storage service, commonly known as Cinder.

If Swift is present and you want to use it, you must enable access to it. If it is not present, or if you do not want to use it, skip this section.

Prerequisites
  • You have a RHOSP administrator account on the target environment.

  • The Swift service is installed.

  • On Ceph RGW, the account in url option is enabled.

Procedure

To enable Swift on RHOSP:

  1. As an administrator in the RHOSP CLI, add the swiftoperator role to the account that will access Swift:

    $ openstack role add --user <user> --project <project> swiftoperator

Your RHOSP deployment can now use Swift for the image registry.

Defining parameters for the installation program

The OpenShift Container Platform installation program relies on a file that is called clouds.yaml. The file describes Red Hat OpenStack Platform (RHOSP) configuration parameters, including the project name, log in information, and authorization service URLs.

Procedure
  1. Create the clouds.yaml file:

    • If your RHOSP distribution includes the Horizon web UI, generate a clouds.yaml file in it.

      Remember to add a password to the auth field. You can also keep secrets in a separate file from clouds.yaml.

    • If your RHOSP distribution does not include the Horizon web UI, or you do not want to use Horizon, create the file yourself. For detailed information about clouds.yaml, see Config files in the RHOSP documentation.

      clouds:
        shiftstack:
          auth:
            auth_url: http://10.10.14.42:5000/v3
            project_name: shiftstack
            username: shiftstack_user
            password: XXX
            user_domain_name: Default
            project_domain_name: Default
        dev-env:
          region_name: RegionOne
          auth:
            username: 'devuser'
            password: XXX
            project_name: 'devonly'
            auth_url: 'https://10.10.14.22:5001/v2.0'
  2. If your RHOSP installation uses self-signed certificate authority (CA) certificates for endpoint authentication:

    1. Copy the certificate authority file to your machine.

    2. Add the cacerts key to the clouds.yaml file. The value must be an absolute, non-root-accessible path to the CA certificate:

      clouds:
        shiftstack:
          ...
          cacert: "/etc/pki/ca-trust/source/anchors/ca.crt.pem"

      After you run the installer with a custom CA certificate, you can update the certificate by editing the value of the ca-cert.pem key in the cloud-provider-config keymap. On a command line, run:

      $ oc edit configmap -n openshift-config cloud-provider-config
  3. Place the clouds.yaml file in one of the following locations:

    1. The value of the OS_CLIENT_CONFIG_FILE environment variable

    2. The current directory

    3. A Unix-specific user configuration directory, for example ~/.config/openstack/clouds.yaml

    4. A Unix-specific site configuration directory, for example /etc/openstack/clouds.yaml

      The installation program searches for clouds.yaml in that order.

Setting cloud provider options

Optionally, you can edit the cloud provider configuration for your cluster. The cloud provider configuration controls how OpenShift Container Platform interacts with Red Hat OpenStack Platform (RHOSP).

For a complete list of cloud provider configuration parameters, see the cloud.conf specification.

Procedure
  1. If you have not already generated manifest files for your cluster, generate them by running the following command:

    $ openshift-install --dir <destination_directory> create manifests
  2. In a text editor, open the cloud-provider configuration manifest file. For example:

    $ vi openshift/manifests/cloud-provider-config.yaml
  3. Modify the options based on the cloud.conf specification.

    Configuring Octavia for load balancing is a common case. For example:

    #...
    [LoadBalancer]
    use-octavia=true (1)
    lb-provider = "amphora" (2)
    floating-network-id="d3deb660-4190-40a3-91f1-37326fe6ec4a"(3)
    #...
    1 This property enables Octavia integration.
    2 This property sets the Octavia provider that your load balancer uses. It accepts "ovn" or "amphora" as values. If you choose to use OVN, you must also set lb-method to SOURCE_IP_PORT.
    3 This property is required if you want to use multiple external networks with your cluster. The cloud provider creates floating IP addresses on the network that is specified here.

    Prior to saving your changes, verify that the file is structured correctly. Clusters might fail if properties are not placed in the appropriate section.

  4. Save the changes to the file and proceed with installation.

    You can update your cloud provider configuration after you run the installer. On a command line, run:

    $ oc edit configmap -n openshift-config cloud-provider-config

    After you save your changes, your cluster will take some time to reconfigure itself. The process is complete if none of your nodes have a SchedulingDisabled status.

Creating the RHCOS image for restricted network installations

Download the Red Hat Enterprise Linux CoreOS (RHCOS) image to install OpenShift Container Platform on a restricted network Red Hat OpenStack Platform (RHOSP) environment.

Prerequisites
  • Obtain the OpenShift Container Platform installation program. For a restricted network installation, the program is on your mirror registry host.

Procedure
  1. Log in to the Red Hat Customer Portal’s Product Downloads page.

  2. Under Version, select the most recent release of OpenShift Container Platform 4.10 for RHEL 8.

    The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available.

  3. Download the Red Hat Enterprise Linux CoreOS (RHCOS) - OpenStack Image (QCOW) image.

  4. Decompress the image.

    You must decompress the image before the cluster can use it. The name of the downloaded file might not contain a compression extension, like .gz or .tgz. To find out if or how the file is compressed, in a command line, enter:

    $ file <name_of_downloaded_file>
  5. Upload the image that you decompressed to a location that is accessible from the bastion server, like Glance. For example:

    $ openstack image create --file rhcos-44.81.202003110027-0-openstack.x86_64.qcow2 --disk-format qcow2 rhcos-${RHCOS_VERSION}

    Depending on your RHOSP environment, you might be able to upload the image in either .raw or .qcow2 formats. If you use Ceph, you must use the .raw format.

    If the installation program finds multiple images with the same name, it chooses one of them at random. To avoid this behavior, create unique names for resources in RHOSP.

The image is now available for a restricted installation. Note the image name or location for use in OpenShift Container Platform deployment.

Creating the installation configuration file

You can customize the OpenShift Container Platform cluster you install on Red Hat OpenStack Platform (RHOSP).

Prerequisites
  • Obtain the OpenShift Container Platform installation program and the pull secret for your cluster. For a restricted network installation, these files are on your mirror host.

  • Have the imageContentSources values that were generated during mirror registry creation.

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

  • Retrieve a Red Hat Enterprise Linux CoreOS (RHCOS) image and upload it to an accessible location.

  • Obtain service principal permissions at the subscription level.

Procedure
  1. Create the install-config.yaml file.

    1. Change to the directory that contains the installation program and run the following command:

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

      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 OpenShift Container Platform version.

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

      1. Optional: Select an SSH key to use to access your cluster machines.

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

      2. Select openstack as the platform to target.

      3. Specify the Red Hat OpenStack Platform (RHOSP) external network name to use for installing the cluster.

      4. Specify the floating IP address to use for external access to the OpenShift API.

      5. Specify a RHOSP flavor with at least 16 GB RAM to use for control plane and compute nodes.

      6. Select the base domain to deploy the cluster to. All DNS records will be sub-domains of this base and will also include the cluster name.

      7. Enter a name for your cluster. The name must be 14 or fewer characters long.

      8. Paste the pull secret from the Red Hat OpenShift Cluster Manager.

  2. In the install-config.yaml file, set the value of platform.openstack.clusterOSImage to the image location or name. For example:

    platform:
      openstack:
          clusterOSImage: http://mirror.example.com/images/rhcos-43.81.201912131630.0-openstack.x86_64.qcow2.gz?sha256=ffebbd68e8a1f2a245ca19522c16c86f67f9ac8e4e0c1f0a812b068b16f7265d
  3. Edit the install-config.yaml file to provide the additional information that is required for an installation in a restricted network.

    1. Update the pullSecret value to contain the authentication information for your registry:

      pullSecret: '{"auths":{"<mirror_host_name>:5000": {"auth": "<credentials>","email": "you@example.com"}}}'

      For <mirror_host_name>, specify the registry domain name that you specified in the certificate for your mirror registry, and for <credentials>, specify the base64-encoded user name and password for your mirror registry.

    2. Add the additionalTrustBundle parameter and value.

      additionalTrustBundle: |
        -----BEGIN CERTIFICATE-----
        ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
        -----END CERTIFICATE-----

      The value must be the contents of the certificate file that you used for your mirror registry, which can be an existing, trusted certificate authority or the self-signed certificate that you generated for the mirror registry.

    3. Add the image content resources, which look like this excerpt:

      imageContentSources:
      - mirrors:
        - <mirror_host_name>:5000/<repo_name>/release
        source: quay.example.com/openshift-release-dev/ocp-release
      - mirrors:
        - <mirror_host_name>:5000/<repo_name>/release
        source: registry.example.com/ocp/release

      To complete these values, use the imageContentSources that you recorded during mirror registry creation.

  4. Make any other modifications to the install-config.yaml file that you require. You can find more information about the available parameters in the Installation configuration parameters section.

  5. Back up the install-config.yaml file so that you can use it to install multiple clusters.

    The install-config.yaml file is consumed during the installation process. If you want to reuse the file, you must back it up now.

Configuring the cluster-wide proxy during installation

Production environments can deny direct access to the internet and instead have an HTTP or HTTPS proxy available. You can configure a new OpenShift Container Platform cluster to use a proxy by configuring the proxy settings in the install-config.yaml file.

Kuryr installations default to HTTP proxies.

Prerequisites
  • For Kuryr installations on restricted networks that use the Proxy object, the proxy must be able to reply to the router that the cluster uses. To add a static route for the proxy configuration, from a command line as the root user, enter:

    $ ip route add <cluster_network_cidr> via <installer_subnet_gateway>
  • The restricted subnet must have a gateway that is defined and available to be linked to the Router resource that Kuryr creates.

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

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

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

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

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

    apiVersion: v1
    baseDomain: my.domain.com
    proxy:
      httpProxy: http://<username>:<pswd>@<ip>:<port> (1)
      httpsProxy: https://<username>:<pswd>@<ip>:<port> (2)
      noProxy: example.com (3)
    additionalTrustBundle: | (4)
        -----BEGIN CERTIFICATE-----
        <MY_TRUSTED_CA_CERT>
        -----END CERTIFICATE-----
    ...
    1 A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
    2 A proxy URL to use for creating HTTPS connections outside the cluster.
    3 A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations.
    4 If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the trustedCA field of the Proxy object. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.

    The installation program does not support the proxy readinessEndpoints field.

  2. Save the file and reference it when installing OpenShift Container Platform.

The installation program creates a cluster-wide proxy that is named cluster that uses the proxy settings in the provided install-config.yaml file. If no proxy settings are provided, a cluster Proxy object is still created, but it will have a nil spec.

Only the Proxy object named cluster is supported, and no additional proxies can be created.

Installation configuration parameters

Before you deploy an OpenShift Container Platform cluster, you provide parameter values to describe your account on the cloud platform that hosts your cluster and optionally customize your cluster’s platform. When you create the install-config.yaml installation configuration file, you provide values for the required parameters through the command line. If you customize your cluster, you can modify the install-config.yaml file to provide more details about the platform.

After installation, you cannot modify these parameters in the install-config.yaml file.

Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 2. Required parameters
Parameter Description Values

apiVersion

The API version for the install-config.yaml content. The current version is v1. The installer may also support older API versions.

String

baseDomain

The base domain of your cloud provider. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the baseDomain and metadata.name parameter values that uses the <metadata.name>.<baseDomain> format.

A fully-qualified domain or subdomain name, such as example.com.

metadata

Kubernetes resource ObjectMeta, from which only the name parameter is consumed.

Object

metadata.name

The name of the cluster. DNS records for the cluster are all subdomains of {{.metadata.name}}.{{.baseDomain}}.

String of lowercase letters, hyphens (-), and periods (.), such as dev. The string must be 14 characters or fewer long.

platform

The configuration for the specific platform upon which to perform the installation: alibabacloud, aws, baremetal, azure, ibmcloud, openstack, ovirt, vsphere, or {}. For additional information about platform.<platform> parameters, consult the table for your specific platform that follows.

Object

pullSecret

Get a pull secret from the Red Hat OpenShift Cluster Manager to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io.

{
   "auths":{
      "cloud.openshift.com":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      },
      "quay.io":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      }
   }
}

Network configuration parameters

You can customize your installation configuration based on the requirements of your existing network infrastructure. For example, you can expand the IP address block for the cluster network or provide different IP address blocks than the defaults.

Only IPv4 addresses are supported.

Table 3. Network parameters
Parameter Description Values

networking

The configuration for the cluster network.

Object

You cannot modify parameters specified by the networking object after installation.

networking.networkType

The cluster network provider Container Network Interface (CNI) plug-in to install.

Either OpenShiftSDN or OVNKubernetes. The default value is OpenShiftSDN.

networking.clusterNetwork

The IP address blocks for pods.

The default value is 10.128.0.0/14 with a host prefix of /23.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23

networking.clusterNetwork.cidr

Required if you use networking.clusterNetwork. An IP address block.

An IPv4 network.

An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between 0 and 32.

networking.clusterNetwork.hostPrefix

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. A hostPrefix value of 23 provides 510 (2^(32 - 23) - 2) pod IP addresses.

A subnet prefix.

The default value is 23.

networking.serviceNetwork

The IP address block for services. The default value is 172.30.0.0/16.

The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network.

An array with an IP address block in CIDR format. For example:

networking:
  serviceNetwork:
   - 172.30.0.0/16

networking.machineNetwork

The IP address blocks for machines.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  machineNetwork:
  - cidr: 10.0.0.0/16

networking.machineNetwork.cidr

Required if you use networking.machineNetwork. An IP address block. The default value is 10.0.0.0/16 for all platforms other than libvirt. For libvirt, the default value is 192.168.126.0/24.

An IP network block in CIDR notation.

For example, 10.0.0.0/16.

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

Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Table 4. Optional parameters
Parameter Description Values

additionalTrustBundle

A PEM-encoded X.509 certificate bundle that is added to the nodes' trusted certificate store. This trust bundle may also be used when a proxy has been configured.

String

cgroupsV2

Enables Linux control groups version 2 (cgroups v2) on specific nodes in your cluster. The OpenShift Container Platform process for enabling cgroups v2 disables all cgroup version 1 controllers and hierarchies. The OpenShift Container Platform cgroups version 2 feature is in Developer Preview and is not supported by Red Hat at this time.

true

compute

The configuration for the machines that comprise the compute nodes.

Array of MachinePool objects.

compute.architecture

Determines the instruction set architecture of the machines in the pool. Currently, clusters with varied architectures are not supported. All pools must specify the same architecture. Valid values are amd64 (the default).

String

compute.hyperthreading

Whether to enable or disable simultaneous multithreading, or hyperthreading, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.