| Authors: | Brian C. Lane <bcl@redhat.com> |
|---|
livemedia-creator uses Anaconda, kickstart and Lorax to create bootable media that use the same install path as a normal system installation. It can be used to make live isos, bootable (partitioned) disk images, tarfiles, and filesystem images for use with virtualization and container solutions like libvirt, docker, and OpenStack.
The general idea is to use virt-install with kickstart and an Anaconda boot.iso to install into a disk image and then use the disk image to create the bootable media.
livemedia-creator –help will describe all of the options available. At the minimum you need:
--make-iso to create a final bootable .iso or one of the other --make-* options.
--iso to specify the Anaconda install media to use with virt-install.
--ks to select the kickstart file describing what to install.
To use livemedia-creator with virtualization you will need to have virt-install installed.
If you are going to be using Anaconda directly, with --no-virt mode, make sure you have the anaconda-tui package installed.
Conventions used in this document:
lmc is an abbreviation for livemedia-creator.
builder is the system where livemedia-creator is being run
image is the disk image being created by running livemedia-creator
See the output from livemedia-creator --help for the commandline arguments.
Run this to create a bootable live iso:
sudo livemedia-creator --make-iso \
--iso=/extra/iso/boot.iso --ks=./docs/rhel7-livemedia.ks
You can run it directly from the lorax git repo like this:
sudo PATH=./src/sbin/:$PATH PYTHONPATH=./src/ ./src/sbin/livemedia-creator \
--make-iso --iso=/extra/iso/boot.iso \
--ks=./docs/rhel7-livemedia.ks --lorax-templates=./share/
You can observe the installation using vnc. The logs will show what port was chosen, or you can use a specific port by passing it. eg. --vnc vnc:127.0.0.1:5
This is usually a good idea when testing changes to the kickstart. lmc tries to monitor the logs for fatal errors, but may not catch everything.
There are 2 stages, the install stage which produces a disk or filesystem image as its output, and the boot media creation which uses the image as its input. Normally you would run both stages, but it is possible to stop after the install stage, by using --image-only, or to skip the install stage and use a previously created disk image by passing --disk-image or --fs-image
When creating an iso virt-install boots using the passed Anaconda installer iso and installs the system based on the kickstart. The %post section of the kickstart is used to customize the installed system in the same way that current spin-kickstarts do.
livemedia-creator monitors the install process for problems by watching the install logs. They are written to the current directory or to the base directory specified by the –logfile command. You can also monitor the install by using a vnc client. This is recommended when first modifying a kickstart, since there are still places where Anaconda may get stuck without the log monitor catching it.
The output from this process is a partitioned disk image. kpartx can be used to mount and examine it when there is a problem with the install. It can also be booted using kvm.
When creating an iso the disk image’s / partition is copied into a formatted filesystem image which is then used as the input to lorax for creation of the final media.
The final image is created by lorax, using the templates in /usr/share/lorax/live/ or the live directory below the directory specified by --lorax-templates. The templates are written using the Mako template system with some extra commands added by lorax.
The docs/ directory includes several example kickstarts, one to create a live desktop iso using GNOME, and another to create a minimal disk image. When creating your own kickstarts you should start with the minimal example, it includes several needed packages that are not always included by dependencies.
Or you can use existing spin kickstarts to create live media with a few changes. Here are the steps I used to convert the Fedora XFCE spin.
Flatten the xfce kickstart using ksflatten
Add zerombr so you don’t get the disk init dialog
Add clearpart –all
Add swap partition
bootloader target
Add shutdown to the kickstart
Add network –bootproto=dhcp –activate to activate the network This works for F16 builds but for F15 and before you need to pass something on the cmdline that activate the network, like sshd:
livemedia-creator --kernel-args="sshd"
Add a root password:
rootpw rootme
network --bootproto=dhcp --activate
zerombr
clearpart --all
bootloader --location=mbr
part swap --size=512
shutdown
In the livesys script section of the %post remove the root password. This really depends on how the spin wants to work. You could add the live user that you create to the %wheel group so that sudo works if you wanted to.
passwd -d root > /dev/null
Remove /etc/fstab in %post, dracut handles mounting the rootfs
cat /dev/null > /dev/fstab
Do this only for live iso’s, the filesystem will be mounted read only if there is no /etc/fstab
Don’t delete initramfs files from /boot in %post
When creating live iso’s you need to have, at least, these packages in the %package section:: dracut-config-generic dracut-live -dracut-config-rescue grub-efi memtest86+ syslinux
One drawback to using virt-install is that it pulls the packages from the repo each time you run it. To speed things up you either need a local mirror of the packages, or you can use a caching proxy. When using a proxy you pass it to livemedia-creator like this:
--proxy=http://proxy.yourdomain.com:3128
You also need to use a specific mirror instead of mirrormanager so that the packages will get cached, so your kickstart url would look like:
url --url="http://dl.fedoraproject.org/pub/fedora/linux/development/rawhide/x86_64/os/"
You can also add an update repo, but don’t name it updates. Add –proxy to it as well.
You can create images without using virt-install by passing --no-virt on the cmdline. This will use Anaconda’s directory install feature to handle the install. There are a couple of things to keep in mind when doing this:
The logs from anaconda will be placed in an ./anaconda/ directory in either the current directory or in the directory used for –logfile
Example cmdline:
sudo livemedia-creator --make-iso --no-virt --ks=./rhel7-livemedia.ks
Note
Using no-virt to create a partitioned disk image (eg. –make-disk or –make-vagrant) will only create disks usable on the host platform (BIOS or UEFI). You can create BIOS partitioned disk images on UEFI by using virt.
Amazon EC2 images can be created by using the –make-ami switch and an appropriate kickstart file. All of the work to customize the image is handled by the kickstart. The example currently included was modified from the cloud-kickstarts version so that it would work with livemedia-creator.
Example cmdline:
sudo livemedia-creator --make-ami --iso=/path/to/boot.iso --ks=./docs/rhel7-livemedia-ec2.ks
This will produce an ami-root.img file in the working directory.
At this time I have not tested the image with EC2. Feedback would be welcome.
livemedia-creator can now replace appliance-tools by using the –make-appliance switch. This will create the partitioned disk image and an XML file that can be used with virt-image to setup a virtual system.
The XML is generated using the Mako template from /usr/share/lorax/appliance/libvirt.xml You can use a different template by passing --app-template <template path>
Documentation on the Mako template system can be found at the Mako site
The name of the final output XML is appliance.xml, this can be changed with --app-file <file path>
The following variables are passed to the template:
- disks
A list of disk_info about each disk. Each entry has the following attributes:
name base name of the disk image file
format “raw”
checksum_type “sha256”
checksum sha256 checksum of the disk image
name Name of appliance, from –app-name argument
arch Architecture
memory Memory in KB (from --ram)
vcpus from --vcpus
networks list of networks from the kickstart or []
title from --title
project from --project
releasever from --releasever
The created image can be imported into libvirt using:
virt-image appliance.xml
You can also create qcow2 appliance images using --image-type=qcow2, for example:
sudo livemedia-creator --make-appliance --iso=/path/to/boot.iso --ks=./docs/rhel7-minimal.ks \
--image-type=qcow2 --app-file=minimal-test.xml --image-name=minimal-test.img
livemedia-creator can be used to create un-partitined filesystem images using the --make-fsimage option. As of version 21.8 this works with both virt and no-virt modes of operation. Previously it was only available with no-virt.
Kickstarts should have a single / partition with no extra mountpoints.
livemedia-creator --make-fsimage --iso=/path/to/boot.iso --ks=./docs/rhel7-minimal.ks
You can name the output image with --image-name and set a label on the filesystem with --fs-label
The --make-tar command can be used to create a tar of the root filesystem. By default it is compressed using xz, but this can be changed using the --compression and --compress-arg options. This option works with both virt and no-virt install methods.
As with --make-fsimage the kickstart should be limited to a single / partition.
For example:
livemedia-creator --make-tar --iso=/path/to/boot.iso --ks=./docs/rhel7-minimal.ks \
--image-name=rhel7-root.tar.xz
The --make-pxe-live command will produce squashfs image containing live root filesystem that can be used for pxe boot. Directory with results will contain the live image, kernel image, initrd image and template of pxe configuration for the images.
The --make-ostree-live command will produce the same result as --make-pxe-live for installations of Atomic Host. Example kickstart for such an installation using Atomic installer iso with local repo included in the image can be found in docs/rhel-atomic-pxe-live.ks.
The PXE images can also be created with --no-virt by using the example kickstart in docs/rhel-atomic-pxe-live-novirt.ks. This also works inside the mock environment.
Sometimes an installation will get stuck. When using virt-install the logs will be written to ./virt-install.log and most of the time any problems that happen will be near the end of the file. lmc tries to detect common errors and will cancel the installation when they happen. But not everything can be caught. When creating a new kickstart it is helpful to use vnc so that you can monitor the installation as it happens, and if it gets stuck without lmc detecting the problem you can switch to tty1 and examine the system directly.
If it does get stuck the best way to cancel is to use kill -9 on the virt-install pid, lmc will detect that the process died and cleanup.
If lmc didn’t handle the cleanup for some reason you can do this: 1. sudo umount /tmp/lmc-XXXX to unmount the iso from its mountpoint. 2. sudo rm -rf /tmp/lmc-XXXX 3. sudo rm /var/tmp/lmc-disk-XXXXX to remove the disk image.
Note that lmc uses the lmc- prefix for all of its temporary files and directories to make it easier to find and clean up leftovers.
The logs from the virt-install run are stored in virt-install.log, logs from livemedia-creator are in livemedia.log and program.log
You can add --image-only to skip the .iso creation and examine the resulting disk image. Or you can pass --keep-image to keep it around after the iso has been created.
Cleaning up aborted --no-virt installs can sometimes be accomplished by running the anaconda-cleanup script. As of Fedora 18 anaconda is multi-threaded and it can sometimes become stuck and refuse to exit. When this happens you can usually clean up by first killing the anaconda process then running anaconda-cleanup.