Chapter 9. Preparing and deploying a KVM Guest Image by using RHEL image builder
Chapter 9. Preparing and deploying a KVM Guest Image by using RHEL image builder Use RHEL image builder to create a .qcow2 purpose-built that you can deploy on a Kernel-based Virtual Machine (KVM) based hypervisor. Creating a customized KVM guest image involves the following high-level steps: Create a blueprint for the .qcow2 image. Create a .qcow2 image by using RHEL image builder. Create a virtual machine from the KVM guest image. 9.1. Creating customized KVM guest images by using RHEL image builder You can create a customized .qcow2 KVM guest image by using RHEL image builder. The following procedure shows the steps on the GUI, but you can also use the CLI. Prerequisites You must be in the root or weldr group to access the system. The cockpit-composer package is installed. On a RHEL system, you have opened the RHEL image builder dashboard of the web console. You have created a blueprint. See Creating a blueprint in the web console interface . Procedure Click the blueprint name you created. Select the tab Images . Click Create Image to create your customized image. The Create Image window opens. From the Type drop-down menu list, select QEMU Image(.qcow2) . Set the size that you want the image to be when instantiated and click Create . A small pop-up on the upper right side of the window informs you that the image creation has been added to the queue. After the image creation process is complete, you can see the Image build complete status. Verification Click the breadcrumbs icon and select the Download option. RHEL image builder downloads the KVM guest image .qcow2 file at your default download location. Additional resources Creating a blueprint in the web console interface 9.2. Creating a virtual machine from a KVM guest image With RHEL image builder, you can build a .qcow2 image, and use a KVM guest image to create a VM. The KVM guest images created using RHEL image builder already have cloud-init installed and enabled. Prerequisites You created a .qcow2 image by using RHEL image builder. See Creating a blueprint in the web console interface. You have the qemu-kvm package installed on your system. You can check if the /dev/kvm device is available on your system, and virtualization features are enabled in the BIOS. You have the libvirt and virt-install packages installed on your system. You have the genisoimage utility, that is provided by the xorriso package, installed on your system. Procedure Move the .qcow2 image that you created by using RHEL image builder to the /var/lib/libvirt/images/ directory. Create a directory, for example, cloudinitiso and navigate to this newly created directory: Create a file named meta-data . Add the following information to this file: Create a file named user-data . Add the following information to the file: ssh_authorized_keys is your SSH public key. You can find your SSH public key in ~/.ssh/ <id_rsa.pub>\ . Use the genisoimage utility to create an ISO image that includes the user-data and meta-data files. Create a new VM from the KVM Guest Image using the virt-install command. Include the ISO image you created on step 4 as an attachment to the VM image. --graphics none - means it is a headless RHEL 9 VM. --vcpus 4 - means that it uses 4 virtual CPUs. --memory 4096 - means it uses 4096 MB RAM. The VM installation starts: Verification After the boot is complete, the VM shows a text login interface. To log in to the local console of the VM, use user the details from the user-data file: Enter admin as a username and press Enter . Enter password as password and press Enter . After the login authentication is complete, you have access to the VM using the CLI. Additional resources Enabling virtualization . Configuring and managing cloud-init for RHEL 9 . cloud-init significant directories and files .
mkdir cloudinitiso cd cloudinitiso instance-id: citest local-hostname: vmname #cloud-config user: admin password: password chpasswd: {expire: False} ssh_pwauth: True ssh_authorized_keys: - ssh-rsa AAA...fhHQ== your.email@example.com genisoimage -output cloud-init.iso -volid cidata -joliet -rock user-data meta-data I: -input-charset not specified, using utf-8 (detected in locale settings) Total translation table size: 0 Total rockridge attributes bytes: 331 Total directory bytes: 0 Path table size(bytes): 10 Max brk space used 0 183 extents written (0 MB) virt-install --memory 4096 --vcpus 4 --name myvm --disk rhel-9-x86_64-kvm.qcow2,device=disk,bus=virtio,format=qcow2 --disk cloud-init.iso,device=cdrom --os-variant rhel 9 --virt-type kvm --graphics none --import Starting install Connected to domain mytestcivm [ OK ] Started Execute cloud user/final scripts. [ OK ] Reached target Cloud-init target. Red Hat Enterprise Linux 9 (Ootpa) Kernel 4.18.0-221.el8.x86_64 on an x86_64