micro/registry/mdns_watcher.go
2019-09-09 05:11:25 -07:00

81 lines
1.4 KiB
Go

package registry
import (
"fmt"
"strings"
"github.com/micro/mdns"
)
type mdnsWatcher struct {
wo WatchOptions
ch chan *mdns.ServiceEntry
exit chan struct{}
// the mdns domain
domain string
}
func (m *mdnsWatcher) Next() (*Result, error) {
for {
select {
case e := <-m.ch:
txt, err := decode(e.InfoFields)
if err != nil {
continue
}
if len(txt.Service) == 0 || len(txt.Version) == 0 {
continue
}
// Filter watch options
// wo.Service: Only keep services we care about
if len(m.wo.Service) > 0 && txt.Service != m.wo.Service {
continue
}
var action string
if e.TTL == 0 {
action = "delete"
} else {
action = "create"
}
service := &Service{
Name: txt.Service,
Version: txt.Version,
Endpoints: txt.Endpoints,
}
// skip anything without the domain we care about
suffix := fmt.Sprintf(".%s.%s.", service.Name, m.domain)
if !strings.HasSuffix(e.Name, suffix) {
continue
}
service.Nodes = append(service.Nodes, &Node{
Id: strings.TrimSuffix(e.Name, suffix),
Address: fmt.Sprintf("%s:%d", e.AddrV4.String(), e.Port),
Metadata: txt.Metadata,
})
return &Result{
Action: action,
Service: service,
}, nil
case <-m.exit:
return nil, ErrWatcherStopped
}
}
}
func (m *mdnsWatcher) Stop() {
select {
case <-m.exit:
return
default:
close(m.exit)
}
}