add config

config/source/consul/watcher.go

@@ -0,0 +1,96 @@
+package consul
+
+import (
+	"errors"
+	"time"
+
+	"github.com/hashicorp/consul/api"
+	"github.com/hashicorp/consul/api/watch"
+	"github.com/micro/go-micro/config/encoder"
+	"github.com/micro/go-micro/config/source"
+)
+
+type watcher struct {
+	e           encoder.Encoder
+	name        string
+	stripPrefix string
+
+	wp   *watch.Plan
+	ch   chan *source.ChangeSet
+	exit chan bool
+}
+
+func newWatcher(key, addr, name, stripPrefix string, e encoder.Encoder) (source.Watcher, error) {
+	w := &watcher{
+		e:           e,
+		name:        name,
+		stripPrefix: stripPrefix,
+		ch:          make(chan *source.ChangeSet),
+		exit:        make(chan bool),
+	}
+
+	wp, err := watch.Parse(map[string]interface{}{"type": "keyprefix", "prefix": key})
+	if err != nil {
+		return nil, err
+	}
+
+	wp.Handler = w.handle
+
+	// wp.Run is a blocking call and will prevent newWatcher from returning
+	go wp.Run(addr)
+
+	w.wp = wp
+
+	return w, nil
+}
+
+func (w *watcher) handle(idx uint64, data interface{}) {
+	if data == nil {
+		return
+	}
+
+	kvs, ok := data.(api.KVPairs)
+	if !ok {
+		return
+	}
+
+	d, err := makeMap(w.e, kvs, w.stripPrefix)
+	if err != nil {
+		return
+	}
+
+	b, err := w.e.Encode(d)
+	if err != nil {
+		return
+	}
+
+	cs := &source.ChangeSet{
+		Timestamp: time.Now(),
+		Format:    w.e.String(),
+		Source:    w.name,
+		Data:      b,
+	}
+	cs.Checksum = cs.Sum()
+
+	w.ch <- cs
+}
+
+func (w *watcher) Next() (*source.ChangeSet, error) {
+	select {
+	case cs := <-w.ch:
+		return cs, nil
+	case <-w.exit:
+		return nil, errors.New("watcher stopped")
+	}
+}
+
+func (w *watcher) Stop() error {
+	select {
+	case <-w.exit:
+		return nil
+	default:
+		w.wp.Stop()
+		close(w.exit)
+	}
+	return nil
+}