Support failover in cluster (experimental)

cluster/raft/utils.go

@@ -0,0 +1,42 @@
+package raft
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/hashicorp/raft"
+)
+
+func (node *Node) Self() string {
+	return node.Cfg.ID()
+}
+
+func (node *Node) State() raft.RaftState {
+	return node.inner.State()
+}
+
+func (node *Node) CommittedIndex() (uint64, error) {
+	stats := node.inner.Stats()
+	committedIndex0 := stats["commit_index"]
+	return strconv.ParseUint(committedIndex0, 10, 64)
+}
+
+func (node *Node) GetLeaderRedisAddress() string {
+	// redis advertise address used as leader id
+	_, id := node.inner.LeaderWithID()
+	return string(id)
+}
+
+func (node *Node) GetNodes() ([]raft.Server, error) {
+	configFuture := node.inner.GetConfiguration()
+	if err := configFuture.Error(); err != nil {
+		return nil, fmt.Errorf("failed to get raft configuration: %v", err)
+	}
+	return configFuture.Configuration().Servers, nil
+}
+
+func (node *Node) GetSlaves(id string) *MasterSlave {
+	node.FSM.mu.RLock()
+	defer node.FSM.mu.RUnlock()
+	return node.FSM.MasterSlaves[id]
+}