Re: [libvirt] [PATCH v2] polkit: Allow password-less access for 'libvirtadm' group

On 04/29/2015 11:28 AM, Daniel P. Berrange wrote: > On Wed, Apr 29, 2015 at 11:04:42AM -0400, Cole Robinson wrote: >> Many users, who admin their own machines, want to be able to access >> system libvirtd via tools like virt-manager without having to enter >> a root password. Just google 'virt-manager without password' and >> you'll find many hits. I've read at least 5 blog posts over the years >> describing slightly different ways of achieving this goal. >> >> Let's finally add official support for this. >> >> Install a polkit-1 rules file granting password-less auth for any user >> in the new 'libvirtadm' group. Create the group on RPM install >> >> https://bugzilla.redhat.com/show_bug.cgi?id=957300 >> --- >> v2: >> - Name the group libvirtadm (danpb) >> - Name the source file libvirt.rules and rename on install (eblake) >> >> daemon/Makefile.am | 13 +++++++++++++ >> daemon/libvirt.rules | 9 +++++++++ >> libvirt.spec.in | 15 +++++++++++++-- >> 3 files changed, 35 insertions(+), 2 deletions(-) >> create mode 100644 daemon/libvirt.rules >> >> diff --git a/daemon/Makefile.am b/daemon/Makefile.am >> index 300b9a5..974feed 100644 >> --- a/daemon/Makefile.am >> +++ b/daemon/Makefile.am >> @@ -53,6 +53,7 @@ EXTRA_DIST = \ >> libvirtd.init.in \ >> libvirtd.upstart \ >> libvirtd.policy.in \ >> + libvirt.rules \ >> libvirtd.sasl \ >> libvirtd.service.in \ >> libvirtd.socket.in \ >> @@ -233,6 +234,8 @@ policyauth = auth_admin_keep_session >> else ! WITH_POLKIT0 >> policydir = $(datadir)/polkit-1/actions >> policyauth = auth_admin_keep >> +rulesdir = $(datadir)/polkit-1/rules.d >> +rulesfile = libvirt.rules >> endif ! WITH_POLKIT0 >> endif WITH_POLKIT >> >> @@ -263,9 +266,19 @@ if WITH_POLKIT >> install-data-polkit:: >> $(MKDIR_P) $(DESTDIR)$(policydir) >> $(INSTALL_DATA) libvirtd.policy $(DESTDIR)$(policydir)/org.libvirt.unix.policy >> +if ! WITH_POLKIT0 >> + $(MKDIR_P) $(DESTDIR)$(rulesdir) >> + $(INSTALL_DATA) $(srcdir)/$(rulesfile) $(DESTDIR)$(rulesdir)/50-libvirt.rules >> +endif ! WITH_POLKIT0 >> + >> uninstall-data-polkit:: >> rm -f $(DESTDIR)$(policydir)/org.libvirt.unix.policy >> rmdir $(DESTDIR)$(policydir) || : >> +if ! WITH_POLKIT0 >> + rm -f $(DESTDIR)$(rulesdir)/50-libvirt.rules >> + rmdir $(DESTDIR)$(rulesdir) || : >> +endif ! WITH_POLKIT0 >> + >> else ! WITH_POLKIT >> install-data-polkit:: >> uninstall-data-polkit:: >> diff --git a/daemon/libvirt.rules b/daemon/libvirt.rules >> new file mode 100644 >> index 0000000..e70c09b >> --- /dev/null >> +++ b/daemon/libvirt.rules >> @@ -0,0 +1,9 @@ >> +// Allow any user in the 'libvirtadm' group to connect to system libvirtd >> +// without entering a password. >> + >> +polkit.addRule(function(action, subject) { >> + if (action.id == "org.libvirt.unix.manage" && >> + subject.isInGroup("libvirtadm")) { >> + return polkit.Result.YES; >> + } >> +}); >> diff --git a/libvirt.spec.in b/libvirt.spec.in >> index 20af502..10a28a2 100644 >> --- a/libvirt.spec.in >> +++ b/libvirt.spec.in >> @@ -1645,9 +1645,9 @@ then >> fi >> >> %if %{with_libvirtd} >> +%pre daemon >> %if ! %{with_driver_modules} >> %if %{with_qemu} >> -%pre daemon >> %if 0%{?fedora} || 0%{?rhel} >= 6 >> # We want soft static allocation of well-known ids, as disk images >> # are commonly shared across NFS mounts by id rather than name; see >> @@ -1661,11 +1661,21 @@ if ! getent passwd qemu >/dev/null; then >> useradd -r -g qemu -G kvm -d / -s /sbin/nologin -c "qemu user" qemu >> fi >> fi >> -exit 0 >> %endif >> %endif >> %endif >> >> + %if %{with_polkit} >> + %if 0%{?fedora} || 0%{?rhel} >= 6 >> +# 'libvirtadm' group is just to allow password-less polkit access to >> +# libvirtd. The uid number is irrelevant, so we use dynamic allocation >> +# described at the above link. >> +getent group libvirtadm >/dev/null || groupadd -r libvirtadm > > Hmm, you know I think we should probably file a bug against the > 'setup' RPM in Fedora to request allocation of a group ID value > for this, so we can default to using a fixed group ID, as we do > for other users/groups we create > The recommendations don't seem to suggest that: https://fedoraproject.org/wiki/Packaging:UsersAndGroups?rd=Packaging/User... Quote: Soft static allocation is only appropriate for packages where the UID or GID values are shared between computers I can't think of a good case when we would need that for libvirtadm... cetainly no files need to be owned by it