Otherwise the creation of `test-xattrs` breaks the check for an empty
directory in libtest.sh, breaking installed-tests.
Signed-off-by: Simon McVittie <smcv@debian.org>
The dirtree object is required for traversing, so don't use the
load_variant_if_exists() function. This will return a
G_IO_ERROR_NOT_FOUND to the caller rather than trying to ref a NULL
variant in ostree_repo_commit_traverse_iter_init_dirtree() if the object
is missing.
https://bugzilla.gnome.org/show_bug.cgi?id=764091
If a commit only pull has been done, then the commit object exists in
the object store in addition to the commitpartial file. Traversing this
partial commit will likely fail, but that's expected. If traverse
returns a G_IO_ERROR_NOT_FOUND in this case, continue with pruning.
https://bugzilla.gnome.org/show_bug.cgi?id=764091
I'm trying to improve the developer experience on OSTree-managed
systems, and I had an epiphany the other day - there's no reason we
have to be absolutely against mutating the current rootfs live. The
key should be making it easy to rollback/reset to a known good state.
I see this command as useful for two related but distinct workflows:
- `ostree admin unlock` will assume you're doing "development". The
semantics hare are that we mount an overlayfs on `/usr`, but the
overlay data is in `/var/tmp`, and is thus discarded on reboot.
- `ostree admin unlock --hotfix` first clones your current deployment,
then creates an overlayfs over `/usr` persistent
to this deployment. Persistent in that now the initramfs switchroot
tool knows how to mount it as well. In this model, if you want
to discard the hotfix, at the moment you roll back/reboot into
the clone.
Note originally, I tried using `rofiles-fuse` over `/usr` for this,
but then everything immediately explodes because the default (at least
CentOS 7) SELinux policy denies tons of things (including `sshd_t`
access to `fusefs_t`). Sigh.
So the switch to `overlayfs` came after experimentation. It still
seems to have some issues...specifically `unix_chkpwd` is broken,
possibly because it's setuid? Basically I can't ssh in anymore.
But I *can* `rpm -Uvh strace.rpm` which is handy.
NOTE: I haven't tested the hotfix path fully yet, specifically
the initramfs bits.
In some cases (such as `ostree-sysroot-cleanup.c`), the surrounding
code would be substantially cleaner if it was also ported to
fd-relative, but I'm going to do that in a separate patch.
That way these patches are easier to review for mechanical
correctness. I used an Emacs keyboard macro as the poor man's
[Coccinelle](http://coccinelle.lip6.fr/).
⚠️ There is a notable spiked pit trap here around
`posix_fallocate()` and `errno`. This has bit other projects,
see e.g.
7bb87460e6
Otherwise the port was straightforward.
Since we hard-depend on GLib 2.40, we can start using GSubprocess.
This is part of dropping our dependency on libgsystem, which is
deprecated in favor of libglnx (as well as migrating things to GLib).
The test tries to get a filesystem that supports xattrs by writing
to /var/tmp, but in some automated build environments the entire
build chroot is on a tmpfs.
Signed-off-by: Simon McVittie <smcv@debian.org>
I'd like to encourage people to make OSTree-managed systems more
strictly read-only in multiple places. Ideally everywhere is
read-only normally besides `/var/`, `/tmp/`, and `/run`.
`/boot` is a good example of something to make readonly. Particularly
now that there's work on the `admin unlock` verb, we need to protect
the system better against things like `rpm -Uvh kernel.rpm` because
the RPM-packaged kernel won't understand how to do OSTree right.
In order to make this work of course, we *do* need to remount `/boot`
as writable when we're doing an upgrade that changes the kernel
configuration. So the strategy is to detect whether it's read-only,
and if so, temporarily mount read-write, then remount read-only when
the upgrade is done.
We can generalize this in the future to also do `/etc` (and possibly
`/sysroot/ostree/` although that gets tricky).
One detail: In order to detect "is this path a mountpoint" is
nontrivial - I looked at copying the systemd code, but the right place
is to use `libmount` anyways.
This content currently lives here:
<https://wiki.gnome.org/Projects/OSTree/RelatedProjects>. Moving it
into the manual in Markdown:
- Makes it look better
- It's more useful alongside the rest of the docs
- Is much less crummy in general than the GNOME wiki
It used to be allowed to run something like "ostree remote refs" on
a read-only (e.g. system) repo. However, the summary cache caused that to
break. This commit just makes it not save the cache if we get some kind
of permission error when writing it. It'll still work, even without the
cache.
https://bugzilla.gnome.org/show_bug.cgi?id=763855
Simon McVittie
Colin Walters
Dan Nicholson
Alexander Larsson
Stef Walter