[Podman] Re: bind-propagation=rshared has no effect

Rudolf Vesely via Podman podman(a)lists.podman.io writes: > On Wednesday, February 23rd, 2022 at 08:52, Giuseppe Scrivano gscrivan(a)redhat.com wrote: > > > Rudolf Vesely via Podman podman(a)lists.podman.io writes: > > > > > On Wednesday, February 23rd, 2022 at 08:17, Giuseppe Scrivano gscrivan(a)redhat.com wrote: > > > > > > > Rudolf Vesely via Podman podman(a)lists.podman.io writes: > > > > > > > > > Hi Everybody, > > > > > > > > > > I tried to mount filesystem inside unprivileged container using > > > > > > > > > > fuse3 and it's working. The only thing I had to do was to mount > > > > > > > > > > /dev/fuse using "--device" and add "SYS_ADMIN" capability. > > > > > > > > > > Example: > > > > > > > > > > podman run \ > > > > > > > > > > -d \ > > > > > > > > > > --device=/dev/fuse \ > > > > > > > > > > --cap-add SYS_ADMIN \ > > > > > > > > > > localhost/myimage > > > > > > > > > > After that I can mount fuse inside. > > > > > > > > > > Now I'd like to access the mounted filesystem from another container in a pod or from the container host. In order to do that I used "bind-propagation=rshared" like this: > > > > > > > > > > podman run \ > > > > > > > > > > --mount=type=bind,source=/from,destination=/to,bind-propagation=rshared \ > > > > > > > > > > -d \ > > > > > > > > > > --device=/dev/fuse \ > > > > > > > > > > --cap-add SYS_ADMIN \ > > > > > > > > > > localhost/myimage > > > > > > > > > > When I mount fuse inside the container into "/to" or "/to/subfolder" I > > > > > > > > > > can again see / access the filesystem from inside of the container but > > > > > > > > > > I don't see it from the host / from another containers in a pod that > > > > > > > > > > mount "/from". > > > > > > > > > > Could you please tell me Am I missing something? > > > > > > > > mount points created from a rootless environment won't be propagated to > > > > > > > > the host, even if you specify rshared. > > > > > > > > They will be propagated in the rootless mount namespace, that you can > > > > > > > > access with "podman unshare". > > > > > > > > You first need to setup a mount point in the "podman unshare" > > > > > > > > environment, e.g.: > > > > > > > > $ podman unshare mount --make-shared --bind /from /from > > > > > > > > $ podman run -v /from:/to:rshared .... > > > > > > > > Is the mount accessible from other containers now? > > > > > > Hi Giuseppe, > > > > > > That was my initial trial since I don't need to access it from the > > > > > > host. I wanted to run two containers - the first mounting FUSE and > > > > > > the second running app that accesses the mounted data. > > > > > > I tried to run the two containers in a pod and outside of the pod. > > > > > > I tried to run the second with > > > > > > podman run --mount=type=bind,source=/from,destination=/to,bind-propagation=rshared > > > > > > and without > > > > > > podman run --mount=type=bind,source=/from,destination=/to > > > > > > and even with > > > > > > podman run --mount=type=bind,source=/from,destination=/to,bind-propagation=rshared --device=/dev/fuse --cap-add SYS_ADMIN > > > > > > But the second container does not see the mounted data. > > > > > > And if I mount the fuse on the first to "/from/mount" and I also > > > > > > "touch /from/abc" then the second container will see the directory > > > > > > "/to/mount" and the file "/to/abc" but the "/to/mount" directory will > > > > > > be empty. > > > > have you used `podman unshare mount --make-shared --bind /from /from` > > > > before creating the first container? > > > > Podman mailing list -- podman(a)lists.podman.io > > > > To unsubscribe send an email to podman-leave(a)lists.podman.io > > The fuse is mounted using rclone: https://rclone.org/commands/rclone_mount/ > > with option: --allow-other > > When I run rclone mount inside of the first container it looks like for example this: > > name_of_s3_mount: on /from type fuse.rclone (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) > > or when mounting as normal user inside of the container: > > name_of_s3_mount: on /from type fuse.rclone (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000,allow_other) > > And I can confirm that in both cases, all users inside of the first container can see the data. > > I've just tried inside of the first container after rclone mount: > > mount --make-shared --rbind /from /from > > and that has no effect. > > Forgot to mention that "/etc/fuse.conf" has "user_allow_other" option on both host and inside of the first container. you need to run `podman unshare mount --make-shared --bind /from /from` from the host before creating the container, not from the container. Please be careful, the `/from` directory must be the same one you use for the source for the bind mount when you create the container: $ mkdir /tmp/from $ podman unshare mount --make-shared --bind /tmp/from /tmp/from $ podman run -d --privileged --rm -v/tmp/from:/to:rshared alpine sh -c 'mount -t tmpfs tmpfs /to; touch /to/new-file; sleep 100' $ podman unshare ls /tmp/from new-file $ ls /tmp/from $ podman run --rm --rm -v/tmp/from:/to alpine sh -c 'ls /to' new-file The new-file is visible from the mount that can be shared among different containers, but it is not visible from the host. Podman mailing list -- podman(a)lists.podman.io To unsubscribe send an email to podman-leave(a)lists.podman.io