Re: [libvirt] [PATCH] m4: Change default QEMU credentials to qemu:qemu

Our current defaults are root:wheel on FreeBSD and macOS, root:root everywhere else. Looking at what downstream distributions actually do, we can see that these defaults are overriden the vast majority of the time, with a number of variations showing up in the wild: * qemu:qemu -> Used by CentOS, Fedora, Gentoo, OpenSUSE, RHEL and... As it turns out, our very own spec file :) * libvirt-qemu:libvirt-qemu -> Used by Debian. * libvirt-qemu:kvm -> Used by Ubuntu. * nobody:nobody -> Used by Arch Linux. Based on the above, we can conclude that qemu:qemu are the preferred credentials to be used when spawning a QEMU process, while our current defaults get very little love. Changing our defaults aligns with what most downstreams are actually doing, promotes running QEMU under a non-root user - which is a very good idea anyway - and shields random people building libvirt from source from unwittingly running their guests as root.

Note that there are a very small number of downstreams that don't override our defaults: Alpine Linux, FreeBSD and macOS. Of those, only Alpine Linux is affected by this change; all three should arguably have been setting --with-qemu-user and --with-qemu-group explicitly regardless of this change. Signed-off-by: Andrea Bolognani <abologna(a)redhat.com&gt; --- Proof that I'm not making any of this up ;) * Alpine Linux https://github.com/alpinelinux/aports/blob/master/main/libvirt/APKBUILD * Arch Linux https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=libvirt-git#n113 * CentOS https://git.centos.org/blob/rpms!libvirt.git/8d86411e5109d791edf49c7f43c0... * Debian https://salsa.debian.org/libvirt-team/libvirt/blob/debian/sid/debian/rule... * Fedora https://src.fedoraproject.org/rpms/libvirt/blob/f29/f/libvirt.spec#_204 * FreeBSD https://github.com/freebsd/freebsd-ports/blob/master/devel/libvirt/Makefile * Gentoo https://github.com/gentoo/gentoo/blob/master/app-emulation/libvirt/libvir... * macOS (Homebrew) https://github.com/Homebrew/homebrew-core/blob/master/Formula/libvirt.rb * OpenSUSE https://build.opensuse.org/package/view_file/openSUSE:Leap:15.0:Update/li... * Ubuntu https://git.launchpad.net/ubuntu/+source/libvirt/tree/debian/rules?h=ubun... * Upstream https://libvirt.org/git/?p=libvirt.git;a=blob;f=libvirt.spec.in;h=b7a35a0... m4/virt-driver-qemu.m4 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/m4/virt-driver-qemu.m4 b/m4/virt-driver-qemu.m4 index cb05c34265..2a1b86e891 100644 --- a/m4/virt-driver-qemu.m4 +++ b/m4/virt-driver-qemu.m4 @@ -44,8 +44,8 @@ AC_DEFUN([LIBVIRT_DRIVER_CHECK_QEMU], [ default_qemu_user=root default_qemu_group=wheel else - default_qemu_user=root - default_qemu_group=root + default_qemu_user=qemu + default_qemu_group=qemu