Chapter 5. Preparing PXE assets for OpenShift Container Platform Use the following procedures to create the assets needed to PXE boot an OpenShift Container Platform cluster using the Agent-based Installer. The assets you create in these procedures will deploy a single-node OpenShift Container Platform installation. You can use these procedures as a basis and modify configurations according to your requirements. See Installing an OpenShift Container Platform cluster with the Agent-based Installer to learn about more configurations available with the Agent-based Installer. 5.1. Prerequisites You reviewed details about the OpenShift Container Platform installation and update processes. 5.2. Downloading the Agent-based Installer Use this procedure to download the Agent-based Installer and the CLI needed for your installation. Procedure Log in to the OpenShift Container Platform web console using your login credentials. Navigate to Datacenter . Click Run Agent-based Installer locally . Select the operating system and architecture for the OpenShift Installer and Command line interface . Click Download Installer to download and extract the install program. Download or copy the pull secret by clicking on Download pull secret or Copy pull secret . Click Download command-line tools and place the openshift-install binary in a directory that is on your PATH . 5.3. Creating the preferred configuration inputs Use this procedure to create the preferred configuration inputs used to create the PXE files. Procedure Install nmstate dependency by running the following command: USD sudo dnf install /usr/bin/nmstatectl -y Place the openshift-install binary in a directory that is on your PATH. Create a directory to store the install configuration by running the following command: USD mkdir ~/<directory_name> Note This is the preferred method for the Agent-based installation. Using GitOps ZTP manifests is optional. Create the install-config.yaml file by running the following command: USD cat << EOF > ./<directory_name>/install-config.yaml apiVersion: v1 baseDomain: test.example.com compute: - architecture: amd64 1 hyperthreading: Enabled name: worker replicas: 0 controlPlane: architecture: amd64 hyperthreading: Enabled name: master replicas: 1 metadata: name: sno-cluster 2 networking: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23 machineNetwork: - cidr: 192.168.0.0/16 networkType: OVNKubernetes 3 serviceNetwork: - 172.30.0.0/16 platform: none: {} pullSecret: '<pull_secret>' 4 sshKey: '<ssh_pub_key>' 5 EOF 1 Specify the system architecture, valid values are amd64 and arm64 . 2 Required. Specify your cluster name. 3 Specify the cluster network plugin to install. The supported values are OVNKubernetes and OpenShiftSDN . The default value is OVNKubernetes . 4 Specify your pull secret. 5 Specify your SSH public key. Note If you set the platform to vSphere or baremetal , you can configure IP address endpoints for cluster nodes in three ways: IPv4 IPv6 IPv4 and IPv6 in parallel (dual-stack) IPv6 is supported only on bare metal platforms. Example of dual-stack networking networking: clusterNetwork: - cidr: 172.21.0.0/16 hostPrefix: 23 - cidr: fd02::/48 hostPrefix: 64 machineNetwork: - cidr: 192.168.11.0/16 - cidr: 2001:DB8::/32 serviceNetwork: - 172.22.0.0/16 - fd03::/112 networkType: OVNKubernetes platform: baremetal: apiVIPs: - 192.168.11.3 - 2001:DB8::4 ingressVIPs: - 192.168.11.4 - 2001:DB8::5 Note When you use a disconnected mirror registry, you must add the certificate file that you created previously for your mirror registry to the additionalTrustBundle field of the install-config.yaml file. Create the agent-config.yaml file by running the following command: USD cat > agent-config.yaml << EOF apiVersion: v1beta1 kind: AgentConfig metadata: name: sno-cluster rendezvousIP: 192.168.111.80 1 hosts: 2 - hostname: master-0 3 interfaces: - name: eno1 macAddress: 00:ef:44:21:e6:a5 rootDeviceHints: 4 deviceName: /dev/sdb networkConfig: 5 interfaces: - name: eno1 type: ethernet state: up mac-address: 00:ef:44:21:e6:a5 ipv4: enabled: true address: - ip: 192.168.111.80 prefix-length: 23 dhcp: false dns-resolver: config: server: - 192.168.111.1 routes: config: - destination: 0.0.0.0/0 -hop-address: 192.168.111.2 -hop-interface: eno1 table-id: 254 EOF 1 This IP address is used to determine which node performs the bootstrapping process as well as running the assisted-service component. You must provide the rendezvous IP address when you do not specify at least one host's IP address in the networkConfig parameter. If this address is not provided, one IP address is selected from the provided hosts' networkConfig . 2 Optional: Host configuration. The number of hosts defined must not exceed the total number of hosts defined in the install-config.yaml file, which is the sum of the values of the compute.replicas and controlPlane.replicas parameters. 3 Optional: Overrides the hostname obtained from either the Dynamic Host Configuration Protocol (DHCP) or a reverse DNS lookup. Each host must have a unique hostname supplied by one of these methods. 4 Enables provisioning of the Red Hat Enterprise Linux CoreOS (RHCOS) image to a particular device. The installation program examines the devices in the order it discovers them, and compares the discovered values with the hint values. It uses the first discovered device that matches the hint value. 5 Optional: Configures the network interface of a host in NMState format. Optional: To create an iPXE script, add the bootArtifactsBaseURL to the agent-config.yaml file: apiVersion: v1beta1 kind: AgentConfig metadata: name: sno-cluster rendezvousIP: 192.168.111.80 bootArtifactsBaseURL: <asset_server_URL> Where <asset_server_URL> is the URL of the server you will upload the PXE assets to. Additional resources Deploying with dual-stack networking . Configuring the install-config yaml file . See Configuring a three-node cluster to deploy three-node clusters in bare metal environments. About root device hints . NMState state examples . Optional: Creating additional manifest files 5.4. Creating the PXE assets Use the following procedure to create the assets and optional script to implement in your PXE infrastructure. Procedure Create the PXE assets by running the following command: USD openshift-install agent create pxe-files The generated PXE assets and optional iPXE script can be found in the boot-artifacts directory. Example filesystem with PXE assets and optional iPXE script boot-artifacts ├─ agent.x86_64-initrd.img ├─ agent.x86_64.ipxe ├─ agent.x86_64-rootfs.img └─ agent.x86_64-vmlinuz Note Red Hat Enterprise Linux CoreOS (RHCOS) supports multipathing on the primary disk, allowing stronger resilience to hardware failure to achieve higher host availability. Multipathing is enabled by default in the agent ISO image, with a default /etc/multipath.conf configuration. Upload the PXE assets and optional script to your infrastructure where they will be accessible during the boot process. Note If you generated an iPXE script, the location of the assets must match the bootArtifactsBaseURL you added to the agent-config.yaml file.

Commands:
sudo dnf install /usr/bin/nmstatectl -y
mkdir ~/<directory_name>
cat << EOF > ./<directory_name>/install-config.yaml apiVersion: v1 baseDomain: test.example.com compute: - architecture: amd64 1 hyperthreading: Enabled name: worker replicas: 0 controlPlane: architecture: amd64 hyperthreading: Enabled name: master replicas: 1 metadata: name: sno-cluster 2 networking: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23 machineNetwork: - cidr: 192.168.0.0/16 networkType: OVNKubernetes 3 serviceNetwork: - 172.30.0.0/16 platform: none: {} pullSecret: '<pull_secret>' 4 sshKey: '<ssh_pub_key>' 5 EOF
networking: clusterNetwork: - cidr: 172.21.0.0/16 hostPrefix: 23 - cidr: fd02::/48 hostPrefix: 64 machineNetwork: - cidr: 192.168.11.0/16 - cidr: 2001:DB8::/32 serviceNetwork: - 172.22.0.0/16 - fd03::/112 networkType: OVNKubernetes platform: baremetal: apiVIPs: - 192.168.11.3 - 2001:DB8::4 ingressVIPs: - 192.168.11.4 - 2001:DB8::5
cat > agent-config.yaml << EOF apiVersion: v1beta1 kind: AgentConfig metadata: name: sno-cluster rendezvousIP: 192.168.111.80 1 hosts: 2 - hostname: master-0 3 interfaces: - name: eno1 macAddress: 00:ef:44:21:e6:a5 rootDeviceHints: 4 deviceName: /dev/sdb networkConfig: 5 interfaces: - name: eno1 type: ethernet state: up mac-address: 00:ef:44:21:e6:a5 ipv4: enabled: true address: - ip: 192.168.111.80 prefix-length: 23 dhcp: false dns-resolver: config: server: - 192.168.111.1 routes: config: - destination: 0.0.0.0/0 next-hop-address: 192.168.111.2 next-hop-interface: eno1 table-id: 254 EOF
apiVersion: v1beta1 kind: AgentConfig metadata: name: sno-cluster rendezvousIP: 192.168.111.80 bootArtifactsBaseURL: <asset_server_URL>
openshift-install agent create pxe-files
boot-artifacts ├─ agent.x86_64-initrd.img ├─ agent.x86_64.ipxe ├─ agent.x86_64-rootfs.img └─ agent.x86_64-vmlinuz