On Wed, May 17, 2017 at 03:08:23PM +0200, Daniel Kučera wrote: > Hi all, > > I'm using libvirt-go and I following code to listen for lifecycle events: > > func event_listen() { > log.Printf("event_listen %s", conf.Libvirt.LocalUrl) > hv, err := libvirt.NewConnect(conf.Libvirt.LocalUrl) > > lifecycleCallback := func(c *libvirt.Connect, d *libvirt.Domain, event > *libvirt.DomainEventLifecycle) { > event_message(c, d, "lifecycle", event) > } > > _, err = hv.DomainEventLifecycleRegister(nil, lifecycleCallback) > if err != nil { > log.Printf("unable to register event callback") > return > } > > log.Printf("Libvirt event listener started") > > go func() { > for err == nil { > err = libvirt.EventRunDefaultImpl() > log.Printf("EventRunDefaultImpl err: %+v", err) > } > time.Sleep(time.Second) > event_listen() > }() > > } > > It works ok until I restart libvirtd (service libvirtd restart). After > that, the inner go func waits some time and continues without error. But > the callback is not working anymore. > > My question is, how can I detect hv reconnect (I guess it's happening in > background) so I know when to reinitialize callbacks? There is a separate event you can listen to that notifies when the connection is closed. See the RegisterCloseCallback() method on the Connect object. Basically register a callback there, and when it fires, unregister your existing domain event callbacks, and close your existing Connect object handle. Then fire a goroutine that loops once every few seconds trying to open a new Connect object, and when that succeeds register new domain event callbacks. 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 :|

On Wed, May 17, 2017 at 03:41:09PM +0200, Daniel Kučera wrote: > Hi Daniel, > > I tried that but it doesn't work: > > func libvirt_close_callback(conn *libvirt.Connect, reason > libvirt.ConnectCloseReason){ > log.Printf("close callback: %+v", reason) > } > > func event_listen() { > log.Printf("event_listen %s", conf.Libvirt.LocalUrl) > hv, err := libvirt.NewConnect(conf.Libvirt.LocalUrl) > > err = hv.RegisterCloseCallback(libvirt_close_callback) > if err != nil { > log.Printf("unable to register close callback") > return > } > ... > > The callback fires only when I kill my app, Looks like you are missing a call to libvirt.EventRegisterDefaultImpl(), which must be the first you do do before even connecting to libvirt. 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 :|

On Wed, May 17, 2017 at 03:49:45PM +0200, Daniel Kučera wrote: > No, I'm not, I'm calling it sooner: > > func libvirt_start() { > libvirt.EventRegisterDefaultImpl() > event_listen() > } Well the following example works as expected for me package main import ( "github.com/libvirt/libvirt-go" "log" ) func libvirt_close_callback(conn *libvirt.Connect, reason libvirt.ConnectCloseReason) { log.Printf("In here") } func main() { libvirt.EventRegisterDefaultImpl() hv, err := libvirt.NewConnect("qemu:///session") err = hv.RegisterCloseCallback(libvirt_close_callback) if err != nil { log.Printf("unable to register close callback") return } for { libvirt.EventRunDefaultImpl() } } Printing out "In here" immediately when I kill libvirtd 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 :|