backport of commit 776a26bce7cf3a320fc7e7f4a6bf9da2b30f3da7 (#18375)

Co-authored-by: James Rasell <jrasell@users.noreply.github.com>

.changelog/18352.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+raft: remove use of deprecated Leader func
+```

helper/snapshot/snapshot_test.go

@@ -110,7 +110,7 @@ func makeRaft(t *testing.T, dir string) (*raft.Raft, *MockFSM) {
 
 	timeout := time.After(10 * time.Second)
 	for {
-		if raft.Leader() != "" {
+		if leaderAddr, _ := raft.LeaderWithID(); leaderAddr != "" {
 			break
 		}
 

nomad/node_endpoint.go

@@ -317,7 +317,8 @@ func equalDevices(n1, n2 *structs.Node) bool {
 
 // constructNodeServerInfoResponse assumes the n.srv.peerLock is held for reading.
 func (n *Node) constructNodeServerInfoResponse(nodeID string, snap *state.StateSnapshot, reply *structs.NodeUpdateResponse) error {
-	reply.LeaderRPCAddr = string(n.srv.raft.Leader())
+	leaderAddr, _ := n.srv.raft.LeaderWithID()
+	reply.LeaderRPCAddr = string(leaderAddr)
 
 	// Reply with config information required for future RPC requests
 	reply.Servers = make([]*structs.NodeServerInfo, 0, len(n.srv.localPeers))

nomad/operator_endpoint.go

@@ -75,7 +75,7 @@ func (op *Operator) RaftGetConfiguration(args *structs.GenericRequest, reply *st
 	}
 
 	// Fill out the reply.
-	leader := op.srv.raft.Leader()
+	leader, _ := op.srv.raft.LeaderWithID()
 	reply.Index = future.Index()
 	for _, server := range future.Configuration().Servers {
 		node := "(unknown)"

nomad/rpc.go

@@ -625,7 +625,7 @@ func (s *Server) getLeader() (bool, *serverParts) {
 	}
 
 	// Get the leader
-	leader := s.raft.Leader()
+	leader, _ := s.raft.LeaderWithID()
 	if leader == "" {
 		return false, nil
 	}
@@ -793,7 +793,8 @@ func (r *rpcHandler) setQueryMeta(m *structs.QueryMeta) {
 		m.KnownLeader = true
 	} else {
 		m.LastContact = time.Since(r.raft.LastContact())
-		m.KnownLeader = (r.raft.Leader() != "")
+		leaderAddr, _ := r.raft.LeaderWithID()
+		m.KnownLeader = (leaderAddr != "")
 	}
 }
 

nomad/server.go

@@ -923,7 +923,7 @@ func (s *Server) setupBootstrapHandler() error {
 	// correct number of servers required for quorum are present).
 	bootstrapFn := func() error {
 		// If there is a raft leader, do nothing
-		if s.raft.Leader() != "" {
+		if leader, _ := s.raft.LeaderWithID(); leader != "" {
 			peersTimeout.Reset(maxStaleLeadership)
 			return nil
 		}
@@ -1948,11 +1948,12 @@ func (s *Server) Stats() map[string]map[string]string {
 	toString := func(v uint64) string {
 		return strconv.FormatUint(v, 10)
 	}
+	leader, _ := s.raft.LeaderWithID()
 	stats := map[string]map[string]string{
 		"nomad": {
 			"server":        "true",
 			"leader":        fmt.Sprintf("%v", s.IsLeader()),
-			"leader_addr":   string(s.raft.Leader()),
+			"leader_addr":   string(leader),
 			"bootstrap":     fmt.Sprintf("%v", s.isSingleServerCluster()),
 			"known_regions": toString(uint64(len(s.peers))),
 		},

nomad/status_endpoint.go

@@ -47,9 +47,9 @@ func (s *Status) Leader(args *structs.GenericRequest, reply *string) error {
 		return err
 	}
 
-	leader := string(s.srv.raft.Leader())
+	leader, _ := s.srv.raft.LeaderWithID()
 	if leader != "" {
-		*reply = leader
+		*reply = string(leader)
 	} else {
 		*reply = ""
 	}