https://github.com/rootfs/install-glusterfs-on-fc21
https://github.com/rootfs/install-glusterfs-on-fc21
Last synced: about 2 months ago
JSON representation
- Host: GitHub
- URL: https://github.com/rootfs/install-glusterfs-on-fc21
- Owner: rootfs
- License: bsd-3-clause
- Created: 2015-03-03T16:31:52.000Z (over 10 years ago)
- Default Branch: master
- Last Pushed: 2018-05-30T15:24:29.000Z (about 7 years ago)
- Last Synced: 2025-03-27T09:51:54.323Z (2 months ago)
- Language: C
- Size: 8.79 KB
- Stars: 8
- Watchers: 2
- Forks: 5
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
## Background
A Docker host (such as CoreOS and RedHat Atomic Host) usually is a minimal OS without Gluster client package. If you want to mount a Gluster filesystem, it is quite hard to do it on the host.
## Solution
I just worked out a solution to create a [Super Privileged Container](http://developerblog.redhat.com/2014/11/06/introducing-a-super-privileged-container-concept/) and run mount in the SPC's namespace but create the mount in host's namespace.
The idea is to inject my own mount before [mount(2)](http://linux.die.net/man/2/mount) is called, so we can reset the namespace, thank Colin for the mount [patch idea](https://lists.projectatomic.io/projectatomic-archives/atomic-devel/2015-February/msg00064.html).
But since I don't want to patch any existing util, I followed [Sage Weil's suggestion](http://pad.ceph.com/p/I-containers) and used [ld.preload](http://man7.org/linux/man-pages/man8/ld.so.8.html) instead. This idea can thus be applied to gluster, nfs, cephfs, and so on, once we update the switch [here](https://github.com/rootfs/install-glusterfs-on-fc21/blob/master/mymount.c#L46)
The code is at my [repo](https://github.com/rootfs/install-glusterfs-on-fc21).
Docker image is [hchen/install-glusterfs-on-fc21](https://registry.hub.docker.com/u/hchen/install-glusterfs-on-fc21/)
## How it works
First pull my Docker image
# docker pull hchen/install-glusterfs-on-fc21
Then run the image in [Super Privileged Container](http://developerblog.redhat.com/2014/11/06/introducing-a-super-privileged-container-concept/) mode
# docker run --privileged -d --net=host -e sysimage=/host -v /:/host -v /dev:/dev -v /proc:/proc -v /var:/var -v /run:/run hchen/install-glusterfs-on-fc21
Get the the container's PID:
# docker inspect --format {{.State.Pid}}
My PID is *865*, I use this process's namespace to run the mount, note the */mnt* is in *host's* name space
# nsenter --mount=/proc/865/ns/mnt mount -t glusterfs : /mnt
Alas, you can check on your Docker host to see this gluster fs mount at */mnt*.