projects / mirror_lxcfs.git / blame
| Commit | Line | Data |
|---|---|---|
| 60f73aff SG |
1 | # lxcfs |
| 2 | ||
| c397924a | 3 | ## Introduction |
| 12993ccc CB |
4 | LXCFS is a small FUSE filesystem written with the intention of making Linux |
| 5 | containers feel more like a virtual machine. It started as a side-project of | |
| 6 | `LXC` but is useable by any runtime. | |
| 758ad80c | 7 | |
| 12993ccc CB |
8 | LXCFS will take care that the information provided by crucial files in `procfs` |
| 9 | such as: | |
| 10 | ||
| 11 | ``` | |
| 12 | /proc/cpuinfo | |
| 13 | /proc/diskstats | |
| 14 | /proc/meminfo | |
| 15 | /proc/stat | |
| 16 | /proc/swaps | |
| 17 | /proc/uptime | |
| 18 | ``` | |
| 19 | ||
| 20 | are container aware such that the values displayed (e.g. in `/proc/uptime`) | |
| 21 | really reflect how long the container is running and not how long the host is | |
| 22 | running. | |
| 23 | ||
| 24 | Prior to the implementation of cgroup namespaces by Serge Hallyn `LXCFS` also | |
| 25 | provided a container aware `cgroupfs` tree. It took care that the container | |
| 26 | only had access to cgroups underneath it's own cgroups and thus provided | |
| 27 | additional safety. For systems without support for cgroup namespaces `LXCFS` | |
| 28 | will still provide this feature. | |
| 955ce662 | 29 | |
| c397924a | 30 | ## Usage |
| 758ad80c SH |
31 | The recommended command to run lxcfs is: |
| 32 | ||
| c397924a | 33 | sudo mkdir -p /var/lib/lxcfs |
| 40dd7f1b | 34 | sudo lxcfs /var/lib/lxcfs |
| 7456f3b5 | 35 | |
| 12993ccc CB |
36 | A container runtime wishing to use `LXCFS` should then bind mount the |
| 37 | approriate files into the correct places on container startup. | |
| 38 | ||
| 39 | ### LXC | |
| 7456f3b5 SG |
40 | In order to use lxcfs with systemd-based containers, you can either use |
| 41 | LXC 1.1 in which case it should work automatically, or otherwise, copy | |
| 77647bf9 EG |
42 | the `lxc.mount.hook` and `lxc.reboot.hook` files (once built) from this tree to |
| 43 | `/usr/share/lxcfs`, make sure it is executable, then add the | |
| 44 | following lines to your container configuration: | |
| 5b1e45dd | 45 | ``` |
| 77647bf9 | 46 | lxc.mount.auto = cgroup:mixed |
| 1a188fcb | 47 | lxc.autodev = 1 |
| ef65395d | 48 | lxc.kmsg = 0 |
| 77647bf9 | 49 | lxc.include = /usr/share/lxc/config/common.conf.d/00-lxcfs.conf |
| 5b1e45dd | 50 | ``` |
| 12993ccc CB |
51 | |
| 52 | ## Upgrading LXCFS without breaking running containers | |
| 53 | LXCFS is implemented using a simple shared library without any external | |
| 54 | dependencies other than `FUSE`. It is completely reloadable without having to | |
| 55 | umount it. This ensures that container can be kept running even when the shared | |
| 56 | library is upgraded. | |
| 57 | ||
| 58 | To force a reload of the shared library at the next possible instance simply | |
| 59 | send `SIGUSR1` to the pid of the running `LXCFS` process. This can be as simple | |
| 60 | as doing: | |
| 61 | ||
| 62 | kill -s USR1 $(pidof lxcfs) |