Currently the scan of the /proc/mounts file used to find cgroup mount points doesn't take into account that mount points may hidden by other mount points. For, example in certain Kubernetes environments the /proc/mounts contains the following lines: cgroup /sys/fs/cgroup/net_prio,net_cls cgroup ... tmpfs /sys/fs/cgroup tmpfs ... cgroup /sys/fs/cgroup/net_cls,net_prio cgroup ... In this particular environment the first mount point is hidden by the second one. The correct mount point is the third one, but libvirt will never process it because it only checks the first mount point for each controller (net_cls in this case). So libvirt will try to use the first mount point, which doesn't actually exist, and the complete detection process will fail. To avoid that issue this patch changes the virCgroupDetectMountsFromFile function so that when there are duplicates it takes the information from the last line in /proc/mounts. This requires removing the previous explicit condition to skip duplicates, and adding code to free the memory used by the processing of duplicated lines. Related-To: https://bugzilla.redhat.com/1468214 Related-To: https://github.com/kubevirt/libvirt/issues/4 Signed-off-by: Juan Hernandez <jhernand@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General
Public License, version 2.1 (or later). Some parts of the code that are
not part of the C library may have the more restrictive GNU General
Public License, version 2.1 (or later). See the files COPYING.LESSER
and COPYING
for full license terms & conditions.
Installation
Libvirt uses the GNU Autotools build system, so in general can be built and installed with the usual commands. For example, to build in a manner that is suitable for installing as root, use:
$ ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make
$ sudo make install
While to build & install as an unprivileged user
$ ./configure --prefix=$HOME/usr
$ make
$ make install
The libvirt code relies on a large number of 3rd party libraries. These will
be detected during execution of the configure
script and a summary printed
which lists any missing (optional) dependencies.
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: