livemedia-creator¶

Quickstart¶

Run this to create a bootable live iso:

sudo livemedia-creator --make-iso \
--iso=/extra/iso/boot.iso --ks=./docs/fedora-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/fedora-livemedia.ks --lorax-templates=./share/

If you want to watch the install you can pass --vnc vnc and use a vnc client to connect to localhost:0

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.

How ISO creation works¶

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 passing --vnc vnc and 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 disk 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/ or the directory specified by --lorax-templates

Currently the standard lorax templates are used to make a bootable iso, but it should be possible to modify them to output other results. They are written using the Mako template system which is very flexible.

Kickstarts¶

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.

1. Flatten the xfce kickstart using ksflatten

2. Add zerombr so you don’t get the disk init dialog

3. Add clearpart –all

4. Add swap partition

5. bootloader target

6. Add shutdown to the kickstart

7. 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"

8. Add a root password:

   rootpw rootme
   network --bootproto=dhcp --activate
   zerombr
   clearpart --all
   bootloader --location=mbr
   part swap --size=512
   shutdown
   

9. 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

10. 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

11. Don’t delete initramfs files from /boot in %post

12. 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.

Anaconda image install (no-virt)¶

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:

1. It will be most reliable when building images for the same release that the host is running. Because Anaconda has expectations about the system it is running under you may encounter strange bugs if you try to build newer or older releases.
2. Make sure selinux is set to permissive or disabled. It won’t install correctly with selinux set to enforcing yet.
3. It may totally trash your host. So far I haven’t had this happen, but the possibility exists that a bug in Anaconda could result in it operating on real devices. I recommend running it in a virt or on a system that you can afford to lose all data from.

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=./fedora-livemedia.ks

AMI Images¶

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/fedora-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.

Appliance Creation¶

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 --qcow2, for example:

sudo livemedia-creator --make-appliance --iso=/path/to/boot.iso --ks=./docs/fedora-minimal.ks \
--qcow2 --app-file=minimal-test.xml --image-name=minimal-test.img

Filesystem Image Creation¶

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-install 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/fedora-minimal.ks

You can name the output image with --image-name and set a label on the filesystem with --fs-label

TAR File Creation¶

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/fedora-minimal.ks \
--image-name=fedora-root.tar.xz

Live Image for PXE Boot¶

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.

Atomic Live Image for PXE Boot¶

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.

Using Mock to Create Images¶

As of lorax version 22.2 you can use livemedia-creator and anaconda version 22.15 inside of a mock chroot with –make-iso and –make-fsimage.

On the host system:

1. yum install -y mock

2. Add a user to the mock group to use for running mock. eg. builder

3. Create a new /etc/mock/ config file based on the rawhide one, or modify the existing one so that the following options are setup:

   config_opts['chroot_setup_cmd'] = 'install @buildsys-build anaconda-tui lorax'
   
   # build results go into /home/builder/results/
   config_opts['plugin_conf']['bind_mount_opts']['dirs'].append(('/home/builder/results','/results/'))
   

   If you are creating images for a branched release of Fedora you should also enable the updates-testing repository so that you get the latest builds in your mock chroot.

The following steps are run as the builder user who is a member of the mock group.

4. Make a directory for results matching the bind mount above mkdir ~/results/

5. Copy the example kickstarts cp /usr/share/docs/lorax/*ks .

6. Make sure tar and dracut-network are in the %packages section and that the url points to the correct repo

7. Init the mock mock -r fedora-rawhide-x86_64 --init

8. Copy the kickstart inside the mock mock -r fedora-rawhide-x86_64 --copyin ./fedora-minimal.ks /root/

9. Make a minimal iso:

   mock -r fedora-rawhide-x86_64 --chroot -- livemedia-creator --no-virt \
   --resultdir=/results/try-1 --logfile=/results/logs/try-1/try-1.log \
   --make-iso --ks /root/fedora-minimal.ks
   

Results will be in ./results/try-1 and logs under /results/logs/try-1/ including anaconda logs and livemedia-creator logs. The new iso will be located at ~/results/try-1/images/boot.iso, and the ~/results/try-1/ directory tree will also contain the vmlinuz, initrd, etc.

OpenStack Image Creation¶

OpenStack supports partitioned disk images so --make-disk can be used to create images for importing into glance, OpenStack’s image storage component. You need to have access to an OpenStack provider that allows image uploads, or setup your own using the instructions from the RDO Project <https://www.rdoproject.org/Quickstart>.

The example kickstart, fedora-openstack.ks, is only slightly different than the fedora-minimal.ks one. It adds the cloud-init and cloud-utils-growpart packages. OpenStack supports setting up the image using cloud-init, and cloud-utils-growpart will grow the image to fit the instance’s disk size.

Create a qcow2 image using the kickstart like this:

sudo livemedia-creator --make-disk --iso=/path/to/boot.iso --ks=/path/to/fedora-openstack.ks --qcow2

Import the resulting disk image into the OpenStack system, either via the web UI, or glance on the cmdline:

glance image-create --name "fedora-openstack" --is-public true --disk-format qcow2 \
--container-format bare --file ./fedora-openstack.qcow2

If qcow2 wasn’t used then --disk-format should be set to raw.

Docker Image Creation¶

Use lmc to create a tarfile as described in the TAR File Creation section, but substitute the fedora-docker.ks example kickstart which removes the requirement for core files and the kernel.

You can then import the tarfile into docker like this (as root):

cat /var/tmp/fedora-root.tar.xz | docker import - fedora-root

And then run bash inside of it:

sudo docker run -i -t fedora-root /bin/bash

Debugging problems¶

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 the --vnc vnc command 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 virsh to destroy the domain.

1. Use sudo virsh list to show the name of the virt. It will start with LiveOS and contain a UUID.
2. Run sudo virsh destroy <name> to destroy the domain.
3. Wait 20 seconds or so for lmc to detect that the domain vanished. It should handle cleanup.

If lmc didn’t handle the cleanup for some reason you can do this: 1. sudo virsh undefine <name> 2. sudo umount /tmp/tmpXXXX to unmount the iso from its mountpoint. 3. sudo rm -rf /tmp/tmpXXXX 4. sudo rm /var/tmp/diskXXXXX to remove the disk image.

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.

Hacking¶

Development on this will take place as part of the lorax project, and on the anaconda-devel-list mailing list, and on github

Feedback, enhancements and bugs are welcome. You can use bugzilla to report bugs against the lorax component.