Node names are not allowed to be empty

command/agent/command.go

@@ -164,7 +164,13 @@ func (c *Command) readConfig() *Config {
 	if config.NodeName == "" {
 		hostname, err := os.Hostname()
 		if err != nil {
-			c.Ui.Error(fmt.Sprintf("Error determining hostname: %s", err))
+			c.Ui.Error(fmt.Sprintf("Error determining node name: %s", err))
+			return nil
+		}
+
+		hostname = strings.TrimSpace(hostname)
+		if hostname == "" {
+			c.Ui.Error("Node name can not be empty")
 			return nil
 		}
 		config.NodeName = hostname

command/agent/command_test.go

@@ -114,6 +114,8 @@ func TestReadCliConfig(t *testing.T) {
 	shutdownCh := make(chan struct{})
 	defer close(shutdownCh)
 
+	// Test config parse
+	{
 		tmpDir, err := ioutil.TempDir("", "consul")
 		if err != nil {
 			t.Fatalf("err: %s", err)
@@ -133,6 +135,23 @@ func TestReadCliConfig(t *testing.T) {
 		if config.AdvertiseAddrWan != "1.2.3.4" {
 			t.Fatalf("expected -advertise-addr-wan 1.2.3.4 got %s", config.AdvertiseAddrWan)
 		}
+	}
+
+	// Test empty node name
+	{
+		cmd := &Command{
+			args: []string{
+				"-node", `""`,
+			},
+			ShutdownCh: shutdownCh,
+			Ui:         new(cli.MockUi),
+		}
+
+		config := cmd.readConfig()
+		if config != nil {
+			t.Errorf(`Expected -node="" to fail`)
+		}
+	}
 }
 
 func TestRetryJoinFail(t *testing.T) {