90bea22c73
Previously, fuse-overlayfs always used user.fuseoverlayfs.override_stat for the upper layer while honoring user.containers.override_stat for lower layers so that it can consume a layer created by containers/storage. It turned out that containers/storage also needs to get the overriding extended attribute set by fuse-overlayfs and to set one for the upper layer to make the root directory of the upper layer inherit the mode of a lower layer. Adding code to get and to set user.fuseoverlayfs.override_stat to containers/storage is a bit ugly. The underlying problem is that fuse-overlayfs changes what name to use ad hoc. Fix it by always preferring user.containers.override_stat, which containers/storage honors, over user.fuseoverlayfs.overlayfs, which is specific to fuse-overlayfs. Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
fuse-overlayfs
An implementation of overlay+shiftfs in FUSE for rootless containers.
Usage:
$ fuse-overlayfs -o lowerdir=lowerdir/a:lowerdir/b,upperdir=up,workdir=workdir merged
Specify a different UID/GID mapping:
$ fuse-overlayfs -o uidmapping=0:10:100:100:10000:2000,gidmapping=0:10:100:100:10000:2000,lowerdir=lowerdir/a:lowerdir/b,upperdir=up,workdir=workdir merged
Requirements:
If you are not using the static build as explained in the next chapter, your system needs libfuse > v3.2.1.
- On Fedora:
dnf install fuse3-devel - On Ubuntu > v19.04:
apt install libfuse3-dev
Also, please note that, when using fuse-overlayfs from a user namespace
(for example, when using rootless podman) a Linux Kernel > v4.18.0 is required.
Static Build:
This project provides a convenient way to automatically perform a static build using a container. The result is a self-contained binary without dependencies, that can be copied across hosts.
-
Install
buildahas explained here; -
Both the build and deploy host require the special device
/dev/fuse; there are a few ways to obtain it:
- install
fuse2orfuse3using the package manager of your choice (dnf, apt, pacman, etc): the install script will usually create the device automatically; or - manually create the device with the command
mknod /dev/fuse -m 0666 c 10 229(see this code)
-
Clone this repository, and switch to the top-level folder containing the file "
Containerfile.static.ubuntu"; -
Launch the build with the command (note the single dot
.at the end):
buildah bud -v $PWD:/build/fuse-overlayfs -t fuse-overlayfs -f ./Containerfile.static.ubuntu .
- Copy the resulting binary to your host:
sudo cp fuse-overlayfs /usr/bin/