extract_untethered_rootimg reports failure, for example when the image
does not fit into the memory backed root, but imageboot.sh ignored it and
booted into the partly extracted root, which then hung later on. Stop
with a message saying why instead.
An untethered or uncompressed diskless boot downloaded the root image
only from the deployment server and retried it forever when that server
failed. Try the other managers that answered discovery as well, as the
tethered urlmount already does.
urlmount limits each small range request to 10 seconds, but the single
whole-image download cannot take a total limit. Give up on a connect
after 10 seconds and on a transfer that stalls for 30 seconds instead,
so a hung server moves on to the next one.
On an untethered root, files the initramfs writes before policy load
and sockets that unsquashfs creates without attributes have no label.
Label every inode without one, as the upper layer is in tethered mode.
With a tethered root (and on EL8 always), the initramfs writes the
overlay upper layer before the SELinux policy is loaded, so those files
are unlabeled_t. On a captured enforcing image sshd-keygen then cannot
search / and the node comes up without sshd.
Label exactly the upper layer paths with matchpathcon and chcon.
setfiles would recurse into the merged tree and restorecon is a no-op
before policy load. Built images have SELinux disabled and skip this.
With installtodisk and confluent_imagemethod=untethered (or
uncompressed) imageboot.sh first extracts the image to RAM and tears
down the image mount and the cryptimg device. installimage then hands
the empty /mnt/remote to image2disk.py, which wipes the target disk and
fails with:
FileNotFoundError: [Errno 2] No such file or directory: '/dev/mapper/cryptimg'
Writing the image to disk never needs the RAM copy, so treat the image
method as tethered when installtodisk is set. The same profile can then
be switched between untethered and installtodisk by only adding or
removing installtodisk.
source_remote imageboot.sh is the last thing the diskless cmdline hook
runs, so returning early on a failed extraction ended the hook and left
dracut to time out. Falling through instead reaches the existing
/sysroot/sbin/init guard, which reports the failure and holds the node so
it stays reachable over ssh, as it did before extraction was checked.
Unfortunately, the problem of urlmount's selinux context is left open.
urlmount starts before policy load, preventing transition.
However the policy blocks access urlmount needs when loaded.
`unsquashfs` can use multiple CPU cores during image extraction, significantly reducing boot time.
For example the whole boot time from PXE to shell on a 8-core VM, from approximately 45 seconds to 20 seconds.
This PR adds `squashfs-tools` as a dependency. Since the package is smaller than 1 MB, the additional image size is justified by the performance improvement.
For backward compatibility, the existing `cp`-based extraction method is used when `unsquashfs` is unavailable, such as with images built before this change.
The extraction logic has also been moved into the common functions and is now shared between EL9, EL10, and Ubuntu.
Both untethered `squashfs` images and `confluent_multisquash` images are supported.
Images must be rebuilt to include `unsquashfs` and benefit from the faster extraction path.
Centralize the SELinux chcon helper and use it for downloaded
systemd units, onboot hooks, and apiclient files across EL7 through EL10.
Include chcon in captured EL initramfs images.
Without this fix the onboot services failed to start on SELinux enabled
captured image.
By default, the squashfs file was being cached as well as the contents after extraction.
This is superfluous pressure on the cache of the OS.
However, it does help keep the image afloat through 'confignet', so
leave it on until onboot completes, then reclaim cache and disable further caching.
Jarrod Johnson
Markus Hilger
Jarrod Johnson