When an empty volume is mounted into a container, Docker will
chown that volume appropriately for use in the container. Podman
does this as well, but there are differences in the details. In
Podman, a chown is presently a one-and-done deal; in Docker, it
will continue so long as the volume remains empty. Mount into a
dozen containers, but never add content, the chown occurs every
time. The chown is also linked to copy-up; it will always occur
when a copy-up occurred, despite the volume now not being empty.
This PR changes our logic to (mostly) match Docker's.
For some reason, the chowning also stops if the volume is chowned
to root at any point. This feels like a Docker bug, but as they
say, bug for bug compatible.
In retrospect, using bools for NeedsChown and NeedsCopyUp was a
mistake. Docker isn't actually tracking this stuff; they're just
doing a copy-up and permissions change unconditionally as long as
the volume is empty. They also have the two linked as one
operation, seemingly, despite happening at very different times
during container init. Replicating that in our stateful system is
nontrivial, hence the need for the new CopiedUp field. Basically,
we never want to chown a volume with contents in it, except if
that data is a result of a copy-up that resulted from mounting
into the current container. Tracking who did the copy-up is the
easiest way to do this.
Fixes#22571
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
Moving from Go module v4 to v5 prepares us for public releases.
Move done using gomove [1] as with the v3 and v4 moves.
[1] https://github.com/KSubedi/gomove
Signed-off-by: Matt Heon <mheon@redhat.com>
This contains the implementation of (most) container functions,
with stubs for all pod and volume functions. Presently accessed
via environment variable only for testing purposes.
Signed-off-by: Matt Heon <mheon@redhat.com>
We added the concept of image volumes in 2.2.0, to support
inspecting an image from within a container. However, this is a
strictly read-only mount, with no modification allowed.
By contrast, the new `image` volume driver creates a c/storage
container as its underlying storage, so we have a read/write
layer. This, in and of itself, is not especially interesting, but
what it will enable in the future is. If we add a new command to
allow these image volumes to be committed, we can now distribute
volumes - and changes to them - via a standard OCI image registry
(which is rather new and quite exciting).
Future work in this area:
- Add support for `podman volume push` (commit volume changes and
push resulting image to OCI registry).
- Add support for `podman volume pull` (currently, we require
that the image a volume is created from be already pulled; it
would be simpler if we had a dedicated command that did the
pull and made a volume from it)
- Add support for scratch images (make an empty image on demand
to use as the base of the volume)
- Add UOR support to `podman volume push` and
`podman volume pull` to enable both with non-image volume
drivers
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
We now use the golang error wrapping format specifier `%w` instead of
the deprecated github.com/pkg/errors package.
[NO NEW TESTS NEEDED]
Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
add two new options to the volume create command: copy and nocopy.
When nocopy is specified, the files from the container image are not
copied up to the volume.
Closes: https://github.com/containers/podman/issues/14722
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
add a new option to completely disable xfs quota usage for a volume.
xfs quota set on a volume, even just for tracking disk usage, can
cause weird errors if the volume is later re-used by a container with
a different quota projid. More specifically, link(2) and rename(2)
might fail with EXDEV if the source file has a projid that is
different from the parent directory.
To prevent such kind of issues, the volume should be created
beforehand with `podman volume create -o o=noquota $ID`
Closes: https://github.com/containers/podman/issues/14049
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Fix handling of "bind" and "tmpfs" olumes to actually work.
Allow bind, tmpfs local volumes to work in rootless mode.
Also removed the string "error" from all error messages that begine with it.
All Podman commands are printed with Error:, so this causes an ugly
stutter.
Fixes: https://github.com/containers/podman/issues/12013
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Podman uses the volume option map to check if it has to mount the volume
or not when the container is started. Commit 28138dafcc39 added to uid
and gid options to this map, however when only uid/gid is set we cannot
mount this volume because there is no filesystem or device specified.
Make sure we do not try to mount the volume when only the uid/gid option
is set since this is a simple chown operation.
Also when a uid/gid is explicity set, do not chown the volume based on
the container user when the volume is used for the first time.
Fixes#10620
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
As part of a fix for an earlier bug (#5698) we added the ability
for Podman to chown volumes to correctly match the user running
in the container, even in adverse circumstances (where we don't
know the right UID/GID until very late in the process). However,
we only did this for volumes created automatically by a
`podman run` or `podman create`. Volumes made by
`podman volume create` do not get this chown, so their
permissions may not be correct. I've looked, and I don't think
there's a good reason not to do this chwon for all volumes the
first time the container is started.
I would prefer to do this as part of volume copy-up, but I don't
think that's really possible (copy-up happens earlier in the
process and we don't have a spec). There is a small chance, as
things stand, that a copy-up happens for one container and then
a chown for a second, unrelated container, but the odds of this
are astronomically small (we'd need a very close race between two
starting containers).
Fixes#9608
Signed-off-by: Matthew Heon <mheon@redhat.com>
We missed bumping the go module, so let's do it now :)
* Automated go code with github.com/sirkon/go-imports-rename
* Manually via `vgrep podman/v2` the rest
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
This implements support for mounting and unmounting volumes
backed by volume plugins. Support for actually retrieving
plugins requires a pull request to land in containers.conf and
then that to be vendored, and as such is not yet ready. Given
this, this code is only compile tested. However, the code for
everything past retrieving the plugin has been written - there is
support for creating, removing, mounting, and unmounting volumes,
which should allow full functionality once the c/common PR is
merged.
A major change is the signature of the MountPoint function for
volumes, which now, by necessity, returns an error. Named volumes
managed by a plugin do not have a mountpoint we control; instead,
it is managed entirely by the plugin. As such, we need to cache
the path in the DB, and calls to retrieve it now need to access
the DB (and may fail as such).
Notably absent is support for SELinux relabelling and chowning
these volumes. Given that we don't manage the mountpoint for
these volumes, I am extremely reluctant to try and modify it - we
could easily break the plugin trying to chown or relabel it.
Also, we had no less than *5* separate implementations of
inspecting a volume floating around in pkg/infra/abi and
pkg/api/handlers/libpod. And none of them used volume.Inspect(),
the only correct way of inspecting volumes. Remove them all and
consolidate to using the correct way. Compat API is likely still
doing things the wrong way, but that is an issue for another day.
Fixes#4304
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
With the advent of Podman 2.0.0 we crossed the magical barrier of go
modules. While we were able to continue importing all packages inside
of the project, the project could not be vendored anymore from the
outside.
Move the go module to new major version and change all imports to
`github.com/containers/libpod/v2`. The renaming of the imports
was done via `gomove` [1].
[1] https://github.com/KSubedi/gomove
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
After a restart, pods and containers both run a refresh()
function to prepare to run after a reboot. Until now, volumes
have not had a similar function, because they had no per-boot
setup to perform.
Unfortunately, this was not noticed when in-memory locking was
introduced to volumes. The refresh() routine is, among other
things, responsible for ensuring that locks are reserved after a
reboot, ensuring they cannot be taken by a freshly-created
container, pod, or volume. If this reservation is not done, we
can end up with two objects using the same lock, potentially
needing to lock each other for some operations - classic recipe
for deadlocks.
Add a refresh() function to volumes to perform lock reservation
and ensure it is called as part of overall refresh().
Fixes#4605Fixes#4621
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
Previously, we only did this for volumes created at the same time
as the container. However, this is not correct behavior - Docker
does so for all named volumes, even those made with
'podman volume create' and mounted into a container later.
Fixes#3945
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
When we fail to remove a container's SHM, that's an error, and we
need to report it as such. This may be part of our lingering
storage woes.
Also, remove MNT_DETACH. It may be another cause of the storage
removal failures.
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
When volume options and the local volume driver are specified,
the volume is intended to be mounted using the 'mount' command.
Supported options will be used to volume the volume before the
first container using it starts, and unmount the volume after the
last container using it dies.
This should work for any local filesystem, though at present I've
only tested with tmpfs and btrfs.
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
I was looking into why we have locks in volumes, and I'm fairly
convinced they're unnecessary.
We don't have a state whose accesses we need to guard with locks
and syncs. The only real purpose for the lock was to prevent
concurrent removal of the same volume.
Looking at the code, concurrent removal ought to be fine with a
bit of reordering - one or the other might fail, but we will
successfully evict the volume from the state.
Also, remove the 'prune' bool from RemoveVolume. None of our
other API functions accept it, and it only served to toggle off
more verbose error messages.
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
iFix builtin volumes to work with podman volume
Currently builtin volumes are not recored in podman volumes when
they are created automatically. This patch fixes this.
Remove container volumes when requested
Currently the --volume option on podman remove does nothing.
This will implement the changes needed to remove the volumes
if the user requests it.
When removing a volume make sure that no container uses the volume.
Signed-off-by: Daniel J Walsh dwalsh@redhat.com
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Add support for podman volume and its subcommands.
The commands supported are:
podman volume create
podman volume inspect
podman volume ls
podman volume rm
podman volume prune
This is a tool to manage volumes used by podman. For now it only handle
named volumes, but eventually it will handle all volumes used by podman.
Signed-off-by: umohnani8 <umohnani@redhat.com>
