From Fedora Project Wiki

Anaconda Updates

anaconda has the capability to incorporate updates at runtime to fix any bugs or issues with the installer. These updates are generally distributed as a disk image file (referred to as updates.img from here on out). The updates.img can be used in a few different ways.


Updates types

There are a number of sources for the updates.

Updates from the Network

The easiest and most popular way to use an updates.img is via the network. This is how almost all updates images you'll see in bug reports and mailing lists are distributed. This does not require you to modify your installation tree at all.

To use this method, you will need to edit your kernel command line to include the inst.updates key, like this: If you're booting via an ISO, to edit the kernel command line, you will need to use the e key in GRUB.

 linux inst.updates=http://some.website.com/path/to/updates.img

If you have multiple network interfaces, anaconda will first prompt you to select one (unless you have used the ksdevice= boot parameter). It will then attempt to configure this link using DHCP. If you require other networking configuration, you will need to use various options. ksdevice= can be used to specify a different network device, and the ip= option (along with others for gateway, nameserver, and so forth) can be used for static configuration. All anaconda config options are described elsewhere .

If you are making your own updates.img, just upload it to a web server you have access to and pass the location as above.

Updates from a disk image

You can also put an updates.img on a block device (either a floppy or a USB key). This can be done only with an ext2 filesystem type of updates.img. For a floppy drive, insert your floppy and then run

 dd if=updates.img of=/dev/fd0 bs=72k count=20

to put the contents of the image on your floppy. Then, boot the installer with

 linux updates

and you will be prompted to provide the location of your update disk.

You can also use a USB key or flash media -- just replace /dev/fd0 with the device that your USB key is at.

Updates from the Tree

If you're doing a CD, hard drive, HTTP, or FTP install you can also put the updates.img in your tree to be picked up by all installs automatically. Put the file in the images/ directory. It must have exactly the name updates.img, even if you received it with a different name.

For NFS installs, there are two options. You can either put the image in images/ as above or explode the image into the RHupdates/ directory in your installation tree.

This updates.img is only retrieved from the location where stage2 image is pulled from. If you use inst.repo boot option to specify your installation tree, but you also use inst.stage2 boot option with a different location, only the inst.stage2 location is going to be searched for the updates.img file, and not the inst.repo location.

How to Create an Anaconda Updates Image

If you are working on anaconda or looking at a bug and want to test your own bug fixes, it's easy to create your own updates.img file. anaconda supports two formats: an ext2 filesystem image and the more common gzip-compressed cpio archive. The automatic tools shipped with anaconda deal in the second form, so that's what will be discussed here.

The easiest way to create an image is to run:

$ scripts/makeupdates -b <builddir>

from the anaconda source tree. This will package up all the changes to the tree since the last release and create a file named "updates.img" in the top of the tree. Remember to use the correct git branch for the Fedora release you are working on or testing. The help screen documents the several options that can be used.

An updates.img can include more than just files from anaconda, though. It can also include shared libraries, graphics, other python modules, and certain data files used by anaconda. To add files to an existing image (or create an entirely new one), just do the following:

$ scripts/upd-updates updates.img file1 file2 ...

Note that the placement of files in an image is a little picky. For instance, python modules must be in their proper subdirectory mirroring the layout of /usr/lib/python?.?/site-packages/.

Another way to create an image containing files outside of anaconda is to create the required filesystem structure and compress it manually. For example, let's say you want to overwrite some configuration file in /etc:

$ mkdir -p updates/etc/
$ cp my.cfg updates/etc/
$ cd updates
$ find . | cpio -o -c | gzip > ../updates.img
$ cd ..

How to Examine an Anaconda Updates Image

updates.img files provided by the Fedora project and generated by the makeupdates script are compressed cpio archives. To examine one of these files, use lsinitrd:

$ lsinitrd updates.img

To explode one, do the following:

$ mkdir dest
$ cd dest
$ gunzip -dc /path/to/updates.img | cpio -id

Advanced Usage

Available Options

   usage: makeupdates [-h] [-k] [-c] [-t TAG] [-o OFFSET] [-p]
                      [-a PATH_TO_RPM [PATH_TO_RPM ...]] [-f ARCH] [-b BUILDDIR]
   
   Make Anaconda updates image
   
   optional arguments:
     -h, --help            show this help message and exit
     -k, --keep            do not delete updates subdirectory
     -c, --compile         compile code if there are isys changes
     -t TAG, --tag TAG     make updates image from TAG to HEAD
     -o OFFSET, --offset OFFSET
                           make image from (latest_tag - OFFSET) to HEAD
     -p, --po              update translations
     -a PATH_TO_RPM [PATH_TO_RPM ...], --add PATH_TO_RPM [PATH_TO_RPM ...]
                           add contents of RPMs to the updates image
     -f ARCH, --fetch ARCH
                           auto-fetch new dependencies from Koji for ARCH
     -b BUILDDIR, --builddir BUILDDIR
                           build directory for shared objects

Including Updates for an Older Installation Image

If your installation image has an older Anaconda (for example you have a Beta image but you want to test all the changes that happened in Anaconda since the image was created), you can use the -t makeupdates option, together with the Anaconda release tag corresponding to the Anaconda version on your image. Makupdates will then include all changes that were added since the given Anaconda version was released.


How to Find Anaconda Version for an Installation Image

There are multiple ways how to do that:

  • switch to TTY1 and check the first line on the screen
  • check the first line of the anaconda.log file in /tmp/ during installation
  • check the first line of the anaconda.log file in /var/log/anaconda on a system installed with your installation image during installation
  • check the version of the Anaconda package in the repository that has been used to generate your installation image

Example

  • boot a Fedora installation image
  • find what version of Anaconda is installed on the image
    • lets say that the image contains Anaconda 22.16-1
    • this version corresponds to the anaconda-22.16-1 Git tag
    • you can run git tag in the Anaconda git repository to list all valid tags
  • run makeupdates -t with the tag:
makeupdates -t anaconda-22.16-1
  • an updates image containing all changes since the commit tagged anaconda-22.16-1 will be created

Including Changes in C Code

While Anaconda is mostly written in Python, there are a few pieces of C code, mostly in the form of custom GTK Widgets and the isys helper module. The makeupdates ignores changes in C code by default, but by passing the -c option you can tell it to look for C code canges, recompile the affected modules and include the resulting binaries in the updates image.

Just take not that for the compilation to finish successfully, the host system needs to match the given Installation Image. This is especially important when rebuilding the custom GTK widgets.

So it is for example not possible to use the -c option on a Fedora 21 system to build an updates image with C code changes for a RHEL7 Installation Image or the other way around.