On Sat, 2017-08-26 at 21:41 +0100, Radostin Stoyanov wrote: > Add "--overwrite" to enforce the overwrite of existing files. > > Add the flag "--absolute-names" to disable the strip of leading '/'s > This is used to get around the error "Cannot open:Permission denied" > which occurs when the qemu driver is used by virt-sandbox. It is used > for unprivileged users to create isolated environment in which tar is > executed to extract the content from container image layers. > > In particular this error occurs when the tar archive contains symbolic > link which has target path starting with '/'. > > Steps to reproduce: > $ mkdir /tmp/foo > $ cd /tmp/foo > $ touch file > $ ln -s /tmp/foo/file link > $ tar -cf archive.tar link > $ mkdir /tmp/foo/dest > $ virt-sandbox -c qemu:///session \ > -m host-bind:/mnt=/tmp/foo/dest \ > -- /bin/tar xf /tmp/foo/archive.tar -C /mnt > > Error message: > tar: link: Cannot open: Permission denied > tar: Exiting with failure status due to previous errors > --- > src/virtBootstrap/utils.py | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/src/virtBootstrap/utils.py b/src/virtBootstrap/utils.py > index 63ef57a..66cd301 100644 > --- a/src/virtBootstrap/utils.py > +++ b/src/virtBootstrap/utils.py > @@ -106,7 +106,11 @@ def safe_untar(src, dest): > > # Compression type is auto detected from tar > # Exclude files under /dev to avoid "Cannot mknod: Operation not permitted" > - params = ['--', '/bin/tar', 'xf', src, '-C', '/mnt', '--exclude', 'dev/*'] > + # Note: Here we use --absolute-names flag to get around the error message > + # "Cannot open: Permission denied" when symlynks are extracted, with the > + # qemu:/// driver. This flag must not be used outside virt-sandbox. > + params = ['--', '/bin/tar', 'xf', src, '-C', '/mnt', '--exclude', 'dev/*', > + '--overwrite', '--absolute-names'] > execute(virt_sandbox + params) > > ACK -- Cedric _______________________________________________ virt-tools-list mailing list virt-tools-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/virt-tools-list
