This is a followup to my message in December suggesting that we deprecate use of the netcf package: https://www.redhat.com/archives/libvir-list/2020-December/msg00183.html (or Message-Id: <4889202b-734c-4d0f-472c-d86894319878@xxxxxxxxxx> for those of you who keep a local archive) Each of these patches takes a baby step in the direction of removing netcf from libvirt: 1) makes it possible to explicitly disable netcf in a build without uninstalling netcf-devel. 2) makes netcf=disabled the default for all normal builds 3) switches all RHEL/Fedora/CentOS rpm builds to disable netcf, and no longer require that netcf and netcf-devel be installed. I purposefully didn't include a patch to completely remove all traces of netcf; we can leave it disabled for awhile before taking that step. Much of the basic functionality provided by the netcf backend to the interface driver is also provided by the udev backend which is used when netcf isn't available. Some differences: 1) the udev backend can't make any modifications to host interface configuration. It is only useful for reading a list of host network devices, and querying some basic status of those interfaces (*not* the contents of configuration files, but how the interface is currently setup) 2) With the netcf backend, "virsh iface-list --all" shows a list of those interfaces that have an ifcfg-blah file in /etc/sysconfig/network-scripts. With the udev backend, the same command shows a list of all network devices currently on the host, as provided by the udev function udev_enumerate_add_match_subsystem(enumerate, "net") (with some exceptions - see udeevGetDevices()). This means that, for example, the bridge devices created by libvirt for virtual networks (virbrX) will show in the list when using udev. 3) The udev backend doesn't fill in IP address info about the devices in the output of "virsh iface-dumpxml" (netcf does). 4) The udev driver *does* go to the trouble of filling in the MTU of every interface, even when it is the default value of 1500. In the end, all the information it reports is correct (well, item (2) is debatable - it depends on what you would use the info for), but it is different, which is why I'm sending this as an RFC - I'd appreciate if people can build and try running something like this script with existing libvirt as well as with the patches applied: http://people.redhat.com/lstump/ncfresults and compare the before/after. The real question is whether or not this difference really "makes a difference" to anyone. My guess/hope is that the answer to this is "no". As far as I know, there aren't any management applications that use the virInterface API (even virt-manager has stopped) so it's probably only humans using virsh that encounter it. (If it's considered important, we could 1) filter out the bridge devices used by libvirt virtual networks, and 2) copy the netcf code that fills in IP address info. I don't want to spend time doing that if nobody's going to use it anyway, though.) Laine Stump (3): build: support explicitly disabling netcf build: make netcf=disabled the default rpm: disable netcf for the interface driver on RHEL/Fedora/CentOS libvirt.spec.in | 8 ++------ meson.build | 9 ++++++--- 2 files changed, 8 insertions(+), 9 deletions(-) -- 2.29.2
