Re: [libvirt PATCH 2/2] build: teach run script how to temporarily stop systemd units

On Wed, Mar 24, 2021 at 05:35:06PM +0100, Martin Kletzander wrote: > On Thu, Mar 18, 2021 at 06:30:27PM +0000, Daniel P. Berrangé wrote: > > When testing locally built daemons on a systemd host there can be quite > > a few systemd units that need temporarily stopping, and ideally > > restarting after the test is complete. This becomes a massive burden > > when modular daemons are running and you want to test libvirtd, as a > > huge number of units need stopping. > > > > The run script can facilitate this usage by looking at what units are > > running and automatically stopping any that are known to conflict with > > the daemon that is about to be run. > > > > It might be worth noting that this only affects running it as root. Good point. One day we might start using systemd for session daemons too[1]. [1] https://gitlab.com/libvirt/libvirt/-/issues/21 but for now this is root only. > > > Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; > > --- > > run.in | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- > > 1 file changed, 84 insertions(+), 2 deletions(-) > > > > diff --git a/run.in b/run.in > > index 99c67c586a..72d299dc4a 100644 > > --- a/run.in > > +++ b/run.in > > @@ -44,6 +44,7 @@ import os > > import os.path > > import random > > import sys > > +import subprocess > > > > # Function to intelligently prepend a path to an environment variable. > > # See https://stackoverflow.com/a/9631350 > > @@ -77,5 +78,86 @@ env["LIBVIRT_DIR_OVERRIDE"] = "1" > > # read problems when using glibc. > > env["MALLOC_PERTURB_"] = "%d" % random.randint(1, 255) > > > > -# Run the program. > > -os.execve(prog, args, env) > > +modular_daemons = [ > > + "virtinterfaced", > > + "virtlxcd", > > + "virtnetworkd", > > + "virtnodedevd", > > + "virtnwfilterd", > > + "virtproxyd", > > + "virtqemud", > > + "virtsecretd", > > + "virtstoraged", > > + "virtvboxd", > > + "virtvzd", > > + "virtxend", > > +] > > + > > +def is_modular_daemon(name): > > + return name in modular_daemons > > + > > +def is_monolithic_daemon(name): > > + return name == "libvirtd" > > + > > +def is_systemd_host(): > > + if os.getuid() != 0: > > + return False > > + return os.path.exists("/run/systemd/system") > > + > > +def daemon_units(name): > > + return [name + suffix for suffix in [ > > + ".service", ".socket", "-ro.socket", "-admin.socket"]] > > + > > +def is_unit_active(name): > > + ret = subprocess.call(["systemctl", "is-active", "-q", name]) > > + return ret == 0 > > + > > +def change_unit(name, action): > > + ret = subprocess.call(["systemctl", action, "-q", name]) > > + return ret == 0 > > + > > +try_stop_units = [] > > +if is_systemd_host(): > > + name = os.path.basename(prog) > > + > > + maybe_stopped_units = [] > > + if is_modular_daemon(name): > > + # Only need to stop libvirtd or this specific modular unit > > + maybe_stopped_units += daemon_units("libvirtd") > > + maybe_stopped_units += daemon_units(name) > > + elif is_monolithic_daemon(name): > > + # Need to stop libvirtd and/or all modular units > > + maybe_stopped_units += daemon_units("libvirtd") > > + for entry in modular_daemons: > > + maybe_stopped_units += daemon_units(entry) > > + > > + for unit in maybe_stopped_units: > > + if is_unit_active(unit): > > + try_stop_units.append(unit) > > + > > +if len(try_stop_units) == 0: > > + # Run the program directly, replacing ourselves > > + os.execve(prog, args, env) > > +else: > > + print("Temporarily stopping systemd units...") > > + stopped_units = [] > > + > > + try: > > + for unit in try_stop_units: > > + print(" > %s" % unit) > > + if not change_unit(unit, "stop"): > > + raise Exception("Unable to stop '%s'" % unit) > > + > > + stopped_units.append(unit) > > + > > + print("Running %s..." % prog) > > + ret = subprocess.call(prog, env=env) > > You are not passing any possible parameters here, I think you meant something > like the following: > > subprocess.call([prog] + args) > > no? Yes, you're right.

Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|