master: close etcd volume id allocator client on shutdown

weed/server/master_server.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/httputil"
 	"net/url"
@@ -71,7 +72,8 @@ type MasterServer struct {
 	option *MasterOption
 	guard  *security.Guard
 
-	preallocateSize int64
+	preallocateSize         int64
+	volumeIdAllocatorCloser io.Closer
 
 	Topo                    *topology.Topology
 	vg                      *topology.VolumeGrowth
@@ -169,10 +171,11 @@ func NewMasterServer(r *mux.Router, option *MasterOption, peers map[string]pb.Se
 	switch v.GetString("master.volume_id_allocator") {
 	case "":
 	case "etcd":
-		allocator, err := newVolumeIdAllocator(v, ms.Topo)
+		allocator, closer, err := newVolumeIdAllocator(v, ms.Topo)
 		if err != nil {
 			glog.Fatalf("volume id allocator: %v", err)
 		}
+		ms.volumeIdAllocatorCloser = closer
 		ms.Topo.SetVolumeIdAllocator(allocator)
 	default:
 		glog.Fatalf("unknown master.volume_id_allocator %q", v.GetString("master.volume_id_allocator"))
@@ -668,6 +671,9 @@ func (ms *MasterServer) Shutdown() {
 	if raftServer != nil {
 		raftServer.Stop()
 	}
+	if ms.volumeIdAllocatorCloser != nil {
+		ms.volumeIdAllocatorCloser.Close()
+	}
 }
 
 func (ms *MasterServer) Reload() {

weed/server/master_volume_id_allocator.go

@@ -3,6 +3,7 @@ package weed_server
 import (
 	"crypto/tls"
 	"fmt"
+	"io"
 	"strings"
 	"time"
 
@@ -14,11 +15,13 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/util"
 )
 
-func newVolumeIdAllocator(v *util.ViperProxy, topo *topology.Topology) (topology.VolumeIdAllocator, error) {
+// newVolumeIdAllocator returns the allocator and an io.Closer to release the
+// etcd client on shutdown; the closer is nil for built-in allocation.
+func newVolumeIdAllocator(v *util.ViperProxy, topo *topology.Topology) (topology.VolumeIdAllocator, io.Closer, error) {
 	servers := v.GetString("master.volume_id_etcd.servers")
 	timeout, err := time.ParseDuration(v.GetString("master.volume_id_etcd.timeout"))
 	if err != nil {
-		return nil, fmt.Errorf("parse master.volume_id_etcd.timeout: %w", err)
+		return nil, nil, fmt.Errorf("parse master.volume_id_etcd.timeout: %w", err)
 	}
 
 	var tlsConfig *tls.Config
@@ -29,7 +32,7 @@ func newVolumeIdAllocator(v *util.ViperProxy, topo *topology.Topology) (topology
 			TrustedCAFile: caFile,
 		}
 		if tlsConfig, err = tlsInfo.ClientConfig(); err != nil {
-			return nil, fmt.Errorf("etcd TLS client configuration error: %w", err)
+			return nil, nil, fmt.Errorf("etcd TLS client configuration error: %w", err)
 		}
 	}
 
@@ -41,13 +44,14 @@ func newVolumeIdAllocator(v *util.ViperProxy, topo *topology.Topology) (topology
 		TLS:         tlsConfig,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("connect volume id etcd: %w", err)
+		return nil, nil, fmt.Errorf("connect volume id etcd: %w", err)
 	}
 
 	glog.Infof("volume id allocator: etcd %s", servers)
-	return topology.NewEtcdVolumeIdAllocator(
-		client.KV,
+	allocator := topology.NewEtcdVolumeIdAllocator(
+		client,
 		v.GetString("master.volume_id_etcd.key_prefix"),
 		timeout,
-		topo.GetMaxVolumeId), nil
+		topo.GetMaxVolumeId)
+	return allocator, allocator, nil
 }