With that, the Dockerfile modifications[0] currently done externally
are done now here. That means that the created rootfs tarball can be
directly used within a Dockerfile to create a container from scratch:
FROM scratch
ADD livecd.ubuntu-oci.rootfs.tar.gz /
CMD ["/bin/bash"]
[0]
https://github.com/tianon/docker-brew-ubuntu-core/blob/master/update.sh
(cherry picked from commit a81972a58b004897bf3e5c14ff371bc2f6b5e4b8)
This is a copy of the ubuntu-base project.
Currently ubuntu-base is used as a base for the docker/OCI container
images. The rootfs tarball that is created with ubuntu-base is
published under [0]. That tarball is used in the FROM statement of the
Dockerfile as base and then a couple of modifications are done inside
of the Dockerfile[1].
The ubuntu-oci project will include the changes that are currently
done in the Dockerfile. With that:
1) a Dockerfile using that tarball will be just a 2 line thing:
FROM scratch
ADD ubuntu-hirsute-core-cloudimg-amd64-root.tar.gz /
CMD ["/bin/bash"]
2) Ubuntu has the full control about the build process of the
docker/OCI container. No external sources (like [1]) need to be
modified anymore.
3) Ubuntu can publish containers without depending on the official
dockerhub containers[2]. Currently the containers for the AWS ECR
registry[3] use as a base[4] the official dockerhub containers. That's
no longer needed because a container just needs a Dockerfile described
in 1)
When the ubuntu-oci project has the modifications from [1] included,
we'll also update [1] to use the ubuntu-oci rootfs tarball as a base
and drop the modifications done at [1].
Note: Creating a new ubuntu-oci project instead of using ubuntu-base
will make sure that we don't break users who are currently using
ubuntu-base rootfs tarballs for doing their own thing.
[0] https://partner-images.canonical.com/core/
[1]
https://github.com/tianon/docker-brew-ubuntu-core/blob/master/update.sh
[2] https://hub.docker.com/_/ubuntu
[3] https://gallery.ecr.aws/ubuntu/ubuntu
[4]
https://launchpad.net/~ubuntu-docker-images/ubuntu-docker-images/+oci/ubuntu/+recipe/ubuntu-20.04
(cherry picked from commit ac4a95b9314cf1f8ce01f42016c271c0a6078372)
I recently pulled initramfs logic out of the base build hook, and
dropped that into the `replace_kernel` function. Any cloud image that
does not leverage the generic virtual kernel was expected to call
`replace_kernel` to pull in a custom kernel. That function will
disable initramfs boot for images that use a custom kernel.
Minimal cloud images on amd64 use the linux-kvm kernel, but the build
hook does not utilize the `replace_kernel` function. Instead, the
kernel flavor is set in `auto/config`. I pulled that logic out of
`auto/config` and am now calling `replace_kernel` in the build hook.
I also moved a call to generate the package list so that it will pick
up the change to the linux-kvm kernel.
Change mount option for ubuntu-cpc images from "defaults" to
"umask=0077". ESP partitions might contain sensitive data and
non-root users shouldn't have read access on it.
With this change, when we attempt to boot with an initramfs and fail,
initrdless_boot_fallback_triggered is set to non-zero in the grubenv.
This value can be checked after boot by looking in /boot/grub/grubenv
or by using the grub-editenv list command.
Addresses LP: #1870189
Initramfs-less boot, which is a boot optimization, should only be
applied where we know it could work for users and provide an improved
boot boot experience; images with custom kernels are candidates for
that.
Generic cloud images with the linux-generic kernel are not able to
boot without an initramfs. Previously, these images attempted to boot
without an initramfs, would fail, and then retry with an initramfs.
This slows the boot and is confusing behavior.
One can call divert_grub; replace_kernel; undivert_grub. And
replace_kernel will call into force_boot_without_initramfs, which
under certain conditions can call divert_grub &
undivert_grub. Resulting in undivert_grub called twice in a row.
When undivert_grub is called twice in a row it wipes
systemd-detect-virt binary from disk, as the rm call is unguarded to
check that there is something to divert if systemd package is
installed. And if the systemd package is not installed, it does not
check that systemd-detect-virt file is in-fact what divert_grub has
created.
Add a guard to check that systemd-detect-virt is the placeholder one,
before removing it.
LP: #1902260
(cherry picked from commit 096a00f40459187719840ccad99e86c7ade2ec12)
Do not use removable uefi bootloader path in the cloud-images by
default, as that prevents upgrades of the bootloader.
LP: #1912830
(cherry picked from commit 7c760864fdcb278ca37396f06f5e3f297428d63d)
