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.

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)

+ except KeyboardInterrupt as ex: + pass + finally: + print("Re-starting original systemd units...") + stopped_units.reverse() + for unit in stopped_units: + print(" > %s" % unit) + if not change_unit(unit, "start"): + print(" ! unable to restart %s" % unit, file=sys.stderr) -- 2.30.2

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 :|