func (c *Conn) initConnection() error {
var err error
c.sysconn, err = dbus.SystemBusPrivate()
if err != nil {
return err
}
// Only use EXTERNAL method, and hardcode the uid (not username)
// to avoid a username lookup (which requires a dynamically linked
// libc)
methods := []dbus.Auth{dbus.AuthExternal(strconv.Itoa(os.Getuid()))}
err = c.sysconn.Auth(methods)
if err != nil {
c.sysconn.Close()
return err
}
err = c.sysconn.Hello()
if err != nil {
c.sysconn.Close()
return err
}
c.sysobj = c.sysconn.Object("org.freedesktop.systemd1", dbus.ObjectPath("/org/freedesktop/systemd1"))
// Setup the listeners on jobs so that we can get completions
c.sysconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
"type='signal', interface='org.freedesktop.systemd1.Manager', member='JobRemoved'")
c.initSubscription()
c.initDispatch()
return nil
}
func (c *Conn) initDispatch() {
ch := make(chan *dbus.Signal, signalBuffer)
c.sysconn.Signal(ch)
go func() {
for {
signal, ok := <-ch
if !ok {
return
}
switch signal.Name {
case "org.freedesktop.systemd1.Manager.JobRemoved":
c.jobComplete(signal)
unitName := signal.Body[2].(string)
var unitPath dbus.ObjectPath
c.sysobj.Call("org.freedesktop.systemd1.Manager.GetUnit", 0, unitName).Store(&unitPath)
if unitPath != dbus.ObjectPath("") {
c.sendSubStateUpdate(unitPath)
}
case "org.freedesktop.systemd1.Manager.UnitNew":
c.sendSubStateUpdate(signal.Body[1].(dbus.ObjectPath))
case "org.freedesktop.DBus.Properties.PropertiesChanged":
if signal.Body[0].(string) == "org.freedesktop.systemd1.Unit" {
// we only care about SubState updates, which are a Unit property
c.sendSubStateUpdate(signal.Path)
}
}
}
}()
}
// ObjectPath creates a dbus.ObjectPath using the rules that systemd uses for
// serializing special characters.
func ObjectPath(path string) dbus.ObjectPath {
path = strings.Replace(path, ".", "_2e", -1)
path = strings.Replace(path, "-", "_2d", -1)
path = strings.Replace(path, "@", "_40", -1)
return dbus.ObjectPath(path)
}