diff options
| author | Valentin Rothberg <rothberg@redhat.com> | 2021-03-02 09:20:53 +0100 |
|---|---|---|
| committer | Valentin Rothberg <rothberg@redhat.com> | 2021-03-04 15:43:12 +0100 |
| commit | a090301bbb10424ce4f99e40c97959f0e8664718 (patch) | |
| tree | 3b2596e3d152204d35162b1ca89f524c5803ad8c /cmd | |
| parent | 833670079c5b1f95fbb7c9bb8ba9095f1c66c7b4 (diff) | |
| download | podman-a090301bbb10424ce4f99e40c97959f0e8664718.tar.gz podman-a090301bbb10424ce4f99e40c97959f0e8664718.tar.bz2 podman-a090301bbb10424ce4f99e40c97959f0e8664718.zip | |
podman cp: support copying on tmpfs mounts
Traditionally, the path resolution for containers has been resolved on
the *host*; relative to the container's mount point or relative to
specified bind mounts or volumes.
While this works nicely for non-running containers, it poses a problem
for running ones. In that case, certain kinds of mounts (e.g., tmpfs)
will not resolve correctly. A tmpfs is held in memory and hence cannot
be resolved relatively to the container's mount point. A copy operation
will succeed but the data will not show up inside the container.
To support these kinds of mounts, we need to join the *running*
container's mount namespace (and PID namespace) when copying.
Note that this change implies moving the copy and stat logic into
`libpod` since we need to keep the container locked to avoid race
conditions. The immediate benefit is that all logic is now inside
`libpod`; the code isn't scattered anymore.
Further note that Docker does not support copying to tmpfs mounts.
Tests have been extended to cover *both* path resolutions for running
and created containers. New tests have been added to exercise the
tmpfs-mount case.
For the record: Some tests could be improved by using `start -a` instead
of a start-exec sequence. Unfortunately, `start -a` is flaky in the CI
which forced me to use the more expensive start-exec option.
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Diffstat (limited to 'cmd')
| -rw-r--r-- | cmd/podman/containers/cp.go | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/cmd/podman/containers/cp.go b/cmd/podman/containers/cp.go index 7887e9539..7a62d982c 100644 --- a/cmd/podman/containers/cp.go +++ b/cmd/podman/containers/cp.go @@ -189,8 +189,9 @@ func copyFromContainer(container string, containerPath string, hostPath string) } putOptions := buildahCopiah.PutOptions{ - ChownDirs: &idPair, - ChownFiles: &idPair, + ChownDirs: &idPair, + ChownFiles: &idPair, + IgnoreDevices: true, } if !containerInfo.IsDir && (!hostInfo.IsDir || hostInfoErr != nil) { // If we're having a file-to-file copy, make sure to |