// initBalancer takes hosts from cfg.ChainedServers and it uses them to create a
// balancer.
func (client *Client) initBalancer(cfg *ClientConfig) (*balancer.Balancer, error) {
if len(cfg.ChainedServers) == 0 {
return nil, fmt.Errorf("No chained servers configured, not initializing balancer")
}
// The dialers slice must be large enough to handle all chained
// servers.
dialers := make([]*balancer.Dialer, 0, len(cfg.ChainedServers))
// Add chained (CONNECT proxy) servers.
log.Debugf("Adding %d chained servers", len(cfg.ChainedServers))
for _, s := range cfg.ChainedServers {
dialer, err := s.Dialer(cfg.DeviceID)
if err == nil {
dialers = append(dialers, dialer)
} else {
log.Errorf("Unable to configure chained server. Received error: %v", err)
}
}
bal := balancer.New(dialers...)
var oldBal *balancer.Balancer
var ok bool
ob, ok := client.bal.Get(0 * time.Millisecond)
if ok {
oldBal = ob.(*balancer.Balancer)
}
log.Trace("Publishing balancer")
client.bal.Set(bal)
if oldBal != nil {
// Close old balancer on a goroutine to avoid blocking here
go func() {
oldBal.Close()
log.Debug("Closed old balancer")
}()
}
return bal, nil
}
