While fsck.ext4 and fsck.vfat are part of the initramfs, it turns out
that fsck itself isn't!
While it normally gets included in the initramfs, for some reason that
doesn't happen with our image creation, so it isn't available on first
boot, so explicitly copy 'fsck' so that it will be included.
For that to work, 'logsave' is needed too, so include that as well.
During boot up, initramfs wants to check the filesystems and it does so
via `fsck`, which then (presumably) checks the filesystem being used
and calls the appropriate fsck.* to do the actual checking.
But when `fsck` itself isn't available you get the following warning:
"Warning: fsck not present, so skipping root file system"
When it is available, you'll get a message like this:
"Begin: Will now check root file system ... fsck from util-linux 2.38.1"
Let's also follow our own advise and not *assume* the needed fsck
programs are present in initramfs, but add them explicitly.
Now we can start the resize operations while knowing the current
filesystem is in a proper/clean state.
The main trigger was a missing program in the initramfs, which probably
everyone assumed was there ... but wasn't. (See next commit ...)
So instead list every program that we need/call, so that we *know* that
that program is included in the initramfs.
Also document this new 'policy'.
Also group the programs by the package which has them and sort the list
alphabetically by the package names.
sfdisk is a bit crusty - it doesn't understand gpt partition tables very well,
for example. By switching to parted, we can handle gpt issues (which may be
useful in the future, and is definitely useful for other boards), and we no
longer have to hardcode that 4M alignment workaround. Parted will tell us
the free space at the end of the disk.
Because we're already using partprobe, there's no additional dependencies
needed.
Switch away from using a systemd service for the initial root resize.
Instead, we resize the root partition and filesystem in the initrd.
To simplify things, the initrd script will check whether it should resize
the partition on every boot. It does this by checking if the entire disk
(ignoring an empty 4MB) is in use. However, the scripts themselves are
deleted from the system after the initrd is generated. After the image
is installed, the resize script should exist only in the initrd. When the
kernel gets upgraded (eg, for a security update) or a new initrd is generated
due to a package install, the new initrd will not contain the resize script.
At that point, nothing will remain from the image's initial resize
bootstrapping process.
This process (but not the scripts) is similar to what cloud-initramfs-growroot
does. However, that particular package has an indirect dependency on Python,
and we don't necessarily want that overhead in our images just for resizing.
Diederik de Haas