consul: test rpc errors returned from remote datacenters

consul/serf.go

@@ -325,6 +325,11 @@ func (s *Server) keyringRPC(
 	args *structs.KeyringRequest,
 	replies *structs.KeyringResponses) error {
 
+	rlen := len(s.remoteConsuls) - 1
+	if rlen == 0 {
+		return nil
+	}
+
 	errorCh := make(chan error)
 	respCh := make(chan *structs.KeyringResponses)
 
@@ -335,7 +340,6 @@ func (s *Server) keyringRPC(
 		go s.forwardKeyringRPC(method, dc, args, errorCh, respCh)
 	}
 
-	rlen := len(s.remoteConsuls) - 1
 	done := 0
 	for {
 		select {

consul/serf_test.go

@@ -1,6 +1,8 @@
 package consul
 
 import (
+	"fmt"
+	"os"
 	"testing"
 )
 
@@ -19,3 +21,25 @@ func TestUserEventNames(t *testing.T) {
 		t.Fatalf("bad: %v", raw)
 	}
 }
+
+func TestKeyringRPCError(t *testing.T) {
+	dir1, s1 := testServerDC(t, "dc1")
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+
+	dir2, s2 := testServerDC(t, "dc2")
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfWANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinWAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// RPC error from remote datacenter is returned
+	if err := s1.keyringRPC("Bad.Method", nil, nil); err == nil {
+		t.Fatalf("bad")
+	}
+}