don't crash when service key exists

cluster/calcium/service.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/pkg/errors"
 	"github.com/projecteru2/core/log"
 	"github.com/projecteru2/core/types"
 	"github.com/projecteru2/core/utils"
@@ -30,10 +31,21 @@ func (c *Calcium) RegisterService(ctx context.Context) (unregister func(), err e
 		return
 	}
 
-	expiry, unregisterService, err := c.registerService(ctx, serviceAddress)
-	if err != nil {
-		log.Errorf("[RegisterService] failed to first register service: %v", err)
-		return
+	var (
+		expiry            <-chan struct{}
+		unregisterService func()
+	)
+	for {
+		if expiry, unregisterService, err = c.registerService(ctx, serviceAddress); err == nil {
+			break
+		}
+		if errors.Is(err, types.ErrKeyExists) {
+			log.Debugf("[RegisterService] service key exists: %v", err)
+			time.Sleep(time.Second)
+			continue
+		}
+		log.Errorf("[RegisterService] failed to first register service: %+v", err)
+		return nil, errors.WithStack(err)
 	}
 
 	wg := &sync.WaitGroup{}

store/etcdv3/meta/ephemeral.go

@@ -6,6 +6,7 @@ import (
 
 	"go.etcd.io/etcd/v3/clientv3"
 
+	"github.com/pkg/errors"
 	"github.com/projecteru2/core/log"
 	"github.com/projecteru2/core/types"
 )
@@ -14,17 +15,17 @@ import (
 func (e *ETCD) StartEphemeral(ctx context.Context, path string, heartbeat time.Duration) (<-chan struct{}, func(), error) {
 	lease, err := e.cliv3.Grant(ctx, int64(heartbeat/time.Second))
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, errors.WithStack(err)
 	}
 
 	switch tx, err := e.cliv3.Txn(ctx).
 		If(clientv3.Compare(clientv3.Version(path), "=", 0)).
 		Then(clientv3.OpPut(path, "", clientv3.WithLease(lease.ID))).
 		Commit(); {
 	case err != nil:
-		return nil, nil, err
+		return nil, nil, errors.WithStack(err)
 	case !tx.Succeeded:
-		return nil, nil, types.NewDetailedErr(types.ErrKeyExists, path)
+		return nil, nil, errors.Wrap(types.ErrKeyExists, path)
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())