Koji/BuildingImages

This page documents how images can be built in Koji. It covers the supported use cases, how to configure your Koji instance to build them, and how to build them once it is ready. This is a very new feature and there hasn't been much external testing yet, so please keep that mind if you run into difficulty. Be certain to read the next section to be certain your use case is supported as well. For additional questions and information, ask around in #koji on FreeNode IRC and sign up to the right mailing lists as the Koji project website dictates.

Supported Images & Use Cases
The way images are created in Koji is fairly straightforward. A chroot is initialized and populated with the packages and their dependencies from the livecd-build or appliance-build package group. Next, the kickstart file is copied into it if it was provided from local storage. If not, it is checked out into it from an SCM. It is then modified to use the repo associated with the build tag for the target specified in the command unless the --repo option was given. Both the original and the modified kickstart files are saved as part of the output for the task for later review. A livecd-creator or appliance-creator command is executed using the mock('--chroot', ...) method. Note: this process runs as root. This produces the desired image which is uploaded to /mnt/koji/images/ /$imageID if it is not a scratch image.

%include macros
A word of caution about kickstart files and the %include macro. livecd-creator and appliance-creator are smart enough to search the current directory of the submitted kickstart file if it has %include macros. If the kickstart specified to koji is from local storage, only that kickstart file will be copied into the chroot, and this creates a problem if it has %include macros, because the other kickstart files it needs will be inaccessible. This issue is not present when the kickstart file is retrieved from a remote SCM (such as the spin-kickstarts git repo), because the entire repository is checked out. Presumably it will include any other kickstart files the specified one is including in the same directory. A workaround for the issue would be to use ksflatten (from pykickstart) on kickstart files with %include macros that are going to be submitted to koji from the user's local disk.

Package Groups in the Kickstart File
Package Groups in the kickstart file cause a problem if the Koji repos do not define them, which they most likely don't since Koji's comps.xml is based on the "groups" set up from the CLI. {livecd,appliance}-creator's behavior is to ignore package groups that are not defined in the repo it is using, so this can be troublesome when creating the image since packages could be left out. There are a couple possible workarounds:


 * do not use package groups in the kickstart file and just specify a huge list of packages
 * use --repo and specify a repo that does have a comps.xml that defines the groups it uses

Only Include RPMs Built in Koji
The image building tasks will fail if your image tries to include a package that was not built in your build system. This is because the package does not have any origin information stored in Koji's database. The repos defined in the kickstart will automatically be overridden with the repo of the build tag for the build target, unless you use the --repo option. Since only packages you have built (or include from an external repo) should be there, you should never have this problem unless you use --repo.

No Signed or Debuginfo RPMs in Koji's Build Tags
If you need signed RPMs or debuginfo RPMs, you will run into trouble because Koji does not keep those in its build tag repos. The only work around for this is to create a repo yourself that includes these RPMs and then use --repo. This will force the image to take RPMs from that repo.

LiveCD-Specific Caveats
While livecd-tools does support building on SELinux disabled hosts, you can run into denials when booting if you create and use new files in the %post section of your kickstart file. If you do, you should either set the labels appropriately at the end of the %post section, or instigate an autorelabel at boot time.

Appliance-Specific Caveats
Koji only supports Appliances that are single disk images. If your kickstart file contains "part" commands for multiple devices, the task will fail. Patches are welcome to remove this limitation.

Build System Preparation
This section assumes you have know-how required to install and configure a new instance of Koji, and that you have already done so. You can learn how to do so here if you need to. Please ensure you are using the latest version of the software and that your database schema is updated as well. You should also have some familiarity with how livecd-creator and appliance-creator work.

Follow this procedure step by step to get things prepared they way they need to be. Italics indicate commands to run on the console. Any time you see, substitute in the desired image type. This can be either "livecd" or "appliance". You can enable both at once as well, just run the command twice using each value for.


 * mkdir /mnt/koji/images: Create a directory to put the finished images. This should be done on the system running kojihub.
 * chown apache:apache /mnt/koji/images: Let apache read and write to it.
 * Version 1.3.2 introduces another PythonOption in kojiweb.conf: KojiImagesURL. This option is set to the URL where completed LiveCD images can be downloaded from. Make sure that your apache server is allowing access to that location.
 * You need to set the topurl option in /etc/kojid/kojid.conf. Usually it looks something like http://your.domain.com/koji
 * koji add-host-to-channel  : add a builder to the channel
 * koji grant-permission : grant the permission to build an image type to a user. This step is optional since admins have all permissions.
 * You will need a tag and target to build the images from. The yum repo generated for the build tag of the target is what Koji will use to populate the LiveCDs with by default. (the alternative is to use the --repo option, more on that later)
 * koji add-group  -build: add the -build group
 * koji add-group-pkg  -build ...: add packages to the -build group. These package lists vary has packages and dependencies change. As of October, 2010 for Fedora 13 the needed packages for each image type are:
 * livecd: bash, coreutils, dbus-python, dmraid, livecd-tools, selinux-policy-targeted, yum
 * appliance: appliance-tools, bash, coreutils, grub, parted, selinux-policy, shadow-utils, policycoreutils

Building an Image
Building a LiveCD in Koji is accomplished with the spin-livecd directive. Like all other Koji directives, usage information is available with --help:

Usage: koji spin-livecd [options]  (Specify the --help global option for a list of other help options)

Options: -h, --help          show this help message and exit --nowait            Don't wait on livecd creation --noprogress        Do not display progress of the upload --background        Run the livecd creation task at a lower priority --isoname=ISONAME   Use a custom name for the iso file --ksurl=SCMURL      The URL to the SCM containing the kickstart file --ksversion=VERSION The syntax version used in the kickstart file --scratch           Create a scratch LiveCD image. --repo=REPO         Specify a comma-separated list of repos that will override the repo used to install RPMs in the LiveCD image. The repo associated with the target is the default.

For appliances, use the spin-appliance directive.

Usage: kojay spin-appliance [options]  (Specify the --help global option for a list of other help options)

Options: -h, --help           show this help message and exit --wait               Wait on the appliance creation, even if running in the background --nowait             Don't wait on appliance creation --noprogress         Do not display progress of the upload --background         Run the appliance creation task at a lower priority --ksurl=SCMURL       The URL to the SCM containing the kickstart file --ksversion=VERSION  The syntax version used in the kickstart file --scratch            Create a scratch appliance --tag                Interpret as a tag instead --repo=REPO          Specify a comma-separated list of repos that will override the repo used to install RPMs in the appliance. The build tag repo associated with the target is the default. --name=NAME          Specify the appliance file name --version=VERSION    Set an appliance version, used in .xml metadata --release=RELEASE    Set an appliance release number, used in .xml metadata --vmem=VMEM          Set the amount of virtual memory in the appliance in                        MB, default is 512 --vcpu=VCPU          Set the number of virtual cpus in the appliance, default is 1 --format=DISK_FORMAT Disk format, default is raw. Other options are qcow, qcow2, and vmx.