In some cases we cannot do a fast bind-mount of the files we want
in our jail since we don't have cap_sys_admin for loolmount inside
eg. docker.
Thus we need to fallback to hard-linking, however various security
systems namespace parts of our tree, such that link() fails with
EXDEV even across the (apparently) same file-system.
As such we need to assemble a copy of what we want to hard-link
close to our jails. However, this needs to be owned by root / the
system to avoid having writable files shared between jails. Hence
we need cap_chown in addition to cap_fowner, to get ownership right
and then hard-link.
Change-Id: Iba0ef46ddbc1c03f3dc7177bc1ec1755624135db
Signed-off-by: Michael Meeks <michael.meeks@collabora.com>
The temporary directories created for convert-to
and insertfile are used only once and should be
cleaned up to avoid clutter.
We also de-poco the temp directory creation as
it doesn't add value and do a bit of cleanup.
Change-Id: Ie1fd5b4749788ff4407f2cc886d405258f65f97a
Signed-off-by: Ashod Nakashian <ashod.nakashian@collabora.co.uk>
We should have no symlinks in the jail whatsoever, except
those we create to files known to exist in the jail.
Unfortunately, some systems have some of the /etc files
as symlinks. When we create hard-links to these files,
they can't be accessed from the jail, since the path
they point to isn't replicated in systemplate and jails.
First change here is to always link to the source file or,
when copying, to copy the source rather than a symlink.
Next, to detect modifications, we compare not just the
size and timestamp, but also the contents. This way we
can be certain that any modification will be detected.
Finally, when we copy at least one file in the
systemplate/etc directory, we flag it by creating the
'copied' file. This way we have a reliable indicator
and don't need to second guess if the files are
hard-linked or copied.
We also avoid some noisy errors when we fail to update
systemplate when it's read-only by first checking
if systemplate is writable or not and insue a friendly
log instead.
Change-Id: Ie8c3e70ea4ec19ee098309f8666c00639fa7319b
We now gracefully fallback to copying when/if systemplate
is readonly.
The bulk of the change is to support proper cleanup in
both cases.
First, we had to move as much of the jail bootstrapping
into the loolwsd-systemplate-setup script, so systemplate
will be as complete as possible before it is locked down.
Next, we needed to update the jail with graceful fallback
to linking/copying upon failure. For that, the jail setup
logic in Kit.cpp has been reworked to support not just
update failures, but also more comprehensive mounting
failures as well.
Finally, jail cleanup now is seamless. To support proper
cleanup when we had mounting enabled but had to fallback,
we mark jails that aren't mounted so we can 'rm -rf' the
contents safely and without fear or causing undue damage
(as unlikely as that is, technically we wouldn't want to
rm systemplate files, if mounting read-only had failed).
There are a few minor refactorings of JailUtil to make
it cleaner and more robust.
Change-Id: Iac34869cb84f45acf64fbbc46d46898367b496d2
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/101260
Tested-by: Jenkins
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Andras Timar <andras.timar@collabora.com>
For various reasons, systemplate may be read-only
or under a different owner and therefore impossible
to update the dynamic files in it.
To support such a scenario, we first link the
eight dynamic files in /etc when creating systemplate.
If this fails, we copy the files.
When creating jails, we always check that all the
dynamic files are up-to-date. If they are, nothing
further is necessary and we bind-mount, if enabled
and possible.
However, if the dynamic files are not up-to-date,
we disable bind-mounting and force linking
the files in the jails. Failing that, we copy them,
which is not ideal, but allows us to ensure the
dynamic files are up-to-date as we copy them too.
Ideally, the dynamic files in question would be
hard-link (or at least soft-linked) in systemplate
at creation. From then on we would bind-mount
the jails and everything would work perfectly and
no files would need updating. This patch is fallback
for when this scheme fails, which should be exceedingly
rare anyway, but which still ensures correct operation.
Change-Id: I09c6f057c49396579aaddb1b8bf4af0930dd4247
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/100834
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Tested-by: Jenkins
Reviewed-by: Andras Timar <andras.timar@collabora.com>
When tests are run in parallel, they will all
compete to update and set up the systemplate
directory, which has a handful of files that
need to be up-to-date. This is a source of errors.
Normally, these files are linked (hard- or soft-
link, whichever succeeds). With linking, we
only need to worry about the initial setup,
as the files will never be out-of-date from
then on. However, when linking fails, we need
to copy the files, and update them (by copying
over fresh versions of the files, if necessary)
every time a new kit is forked. Copying over
is tricky, as it's not atomic. To make it
atomic, we copy the files to the destination
directory under a temporary (random) name,
and then rename to the final name (which is
atomic, including replacing the target file,
if it exists).
No such race exists in production, where there
is (or should be) but one instance of loolwsd
(which does the initial setup) and forkit
(which updates systemplate before forking
new kit instances).
This is an issue with parallel tests only.
Change-Id: I6ba1514d00a84da7397d28efeb6378619711d52f
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/97785
Tested-by: Jenkins
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
The new utility is safer and more readable.
Change-Id: I3a86675378d458cb004e5534dbf2b401936d0e57
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/98183
Tested-by: Jenkins
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
loolmount now works and supports mounting and
unmounting, plus numerous improvements,
refactoring, logging, etc.. When enabled,
binding improves the jail setup time by anywhere
from 2x to orders of magnitude (in docker, f.e.).
A new config entry mount_jail_tree controls
whether mounting is used or the old method of
linking/copying of jail contents. It is set to
true by default and falls back to linking/copying.
A test mount is done when the setting is enabled,
and if mounting fails, it's disabled to avoid noise.
Temporarily disabled for unit-tests until we can
cleanup lingering mounts after Jenkins aborts our
build job. In a future patch we will have mount/jail
cleanup as part of make.
The network/system files in /etc that need frequent
refreshing are now updated in systemplate to make
their most recent version available in the jails.
These files can change during the course of loolwsd
lifetime, and are unlikely to be updated in
systemplate after installation at all. We link to
them in the systemplate/etc directory, and if that
fails, we copy them before forking each kit
instance to have the latest.
This reworks the approach used to bind-mount the
jails and the templates such that the total is
now down to only three mounts: systemplate, lo, tmp.
As now systemplate and lotemplate are shared, they
must be mounted as readonly, this means that user/
must now be moved into tmp/user/ which is writable.
The mount-points must be recursive, because we mount
lo/ within the mount-point of systemplate (which is
the root of the jail). But because we (re)bind
recursively, and because both systemplate and
lotemplate are mounted for each jails, we need to
make them unbindable, so they wouldn't multiply the
mount-points for each jails (an explosive growth!)
Contrarywise, we don't want the mount-points to
be shared, because we don't expect to add/remove
mounts after a jail is created.
The random temp directory is now created and set
correctly, plus many logging and other improvements.
Change-Id: Iae3fda5e876cf47d2cae6669a87b5b826a8748df
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/92829
Tested-by: Jenkins
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
