Re: [PATCH 02/26] remote: notify systemd when reloading config

On Wed, Jan 08, 2025 at 19:42:35 +0000, Daniel P. Berrangé wrote: > Switch to the 'notify-reload' service type and send notifications to > systemd when reloading configuration. > > Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; > --- > src/remote/libvirtd.service.in | 2 +- > src/remote/remote_daemon.c | 2 ++ > src/virtd.service.in | 2 +- > 3 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/src/remote/libvirtd.service.in b/src/remote/libvirtd.service.in > index 250b4a6fc3..b0a062e885 100644 > --- a/src/remote/libvirtd.service.in > +++ b/src/remote/libvirtd.service.in > @@ -26,7 +26,7 @@ After=xencommons.service > Conflicts=xendomains.service > > [Service] > -Type=notify > +Type=notify-reload ^^^ > Environment=LIBVIRTD_ARGS="--timeout 120" > EnvironmentFile=-@initconfdir@/libvirtd > ExecStart=@sbindir@/libvirtd $LIBVIRTD_ARGS > diff --git a/src/remote/remote_daemon.c b/src/remote/remote_daemon.c > index 1d079c7e4b..d44a365000 100644 > --- a/src/remote/remote_daemon.c > +++ b/src/remote/remote_daemon.c > @@ -452,9 +452,11 @@ static void daemonReloadHandlerThread(void *opaque G_GNUC_UNUSED) > virHookCall(VIR_HOOK_DRIVER_DAEMON, "-", > VIR_HOOK_DAEMON_OP_RELOAD, SIGHUP, "SIGHUP", NULL, NULL); > > + virSystemdNotifyReload(); The man page says for 'notify-reload': • Behavior of notify-reload is similar to notify, with one difference: the SIGHUP UNIX process signal is sent to the service's main process when the service is asked to reload and the manager will wait for a notification about the reload being finished. When initiating the reload process the service is expected to reply with a notification message via sd_notify(3) that contains the "RELOADING=1" field in combination with "MONOTONIC_USEC=" set to the current monotonic time (i.e. CLOCK_MONOTONIC in clock_gettime(2)) in μs, formatted as decimal string. Once reloading is complete another notification message must be sent, containing "READY=1". Using this service type and implementing this reload protocol is an efficient alternative to providing an ExecReload= command for reloading of the service's configuration. So IIUC we need to be also sending MONOTONIC_USEC= in addition to RELOADING=1 in order to do the handshake for 'notify-reload' properly.