请问下各位老师，最近在看tiup 源码
src/tiup-1.11.0/pkg/cluster/manager/manager.go 里面有这么一行
metadata = m.specManager.NewMetadata()
https://github.com/pingcap/tiup/blob/master/pkg/cluster/manager/manager.go#:~:text=metadata%20%3D%20m.specManager.NewMetadata()
这里其实调用m.specManager.NewMetadata() 后返回的是1个接口（这里还不是很懂为什么这么写）
但是我自己模拟这部分代码写的时候，发现报错，烦请各位老师看下，哪里写错了
type Metadata interface {
GetTopology() Topology
}
type Topology interface {
Type() string
}
func (s *Specification) Type() string {
TopoTypeTiDB := "tidb-cluster"
return TopoTypeTiDB
//TopoTypeTiDB = "tidb-cluster"
}
type Specification struct {
GlobalOptions GlobalOptions `yaml:"global,omitempty" validate:"global:editable"`
//MonitoredOptions MonitoredOptions `yaml:"monitored,omitempty" validate:"monitored:editable"`
//ServerConfigs ServerConfigs `yaml:"server_configs,omitempty" validate:"server_configs:ignore"`
//TiDBServers []*TiDBSpec `yaml:"tidb_servers"`
//TiKVServers []*TiKVSpec `yaml:"tikv_servers"`
//TiFlashServers []*TiFlashSpec `yaml:"tiflash_servers"`
//PDServers []*PDSpec `yaml:"pd_servers"`
//DashboardServers []*DashboardSpec `yaml:"tidb_dashboard_servers,omitempty"`
//PumpServers []*PumpSpec `yaml:"pump_servers,omitempty"`
//Drainers []*DrainerSpec `yaml:"drainer_servers,omitempty"`
//CDCServers []*CDCSpec `yaml:"cdc_servers,omitempty"`
//TiKVCDCServers []*TiKVCDCSpec `yaml:"kvcdc_servers,omitempty"`
//TiSparkMasters []*TiSparkMasterSpec `yaml:"tispark_masters,omitempty"`
//TiSparkWorkers []*TiSparkWorkerSpec `yaml:"tispark_workers,omitempty"`
//Monitors []*PrometheusSpec `yaml:"monitoring_servers"`
//Grafanas []*GrafanaSpec `yaml:"grafana_servers,omitempty"`
//Alertmanagers []*AlertmanagerSpec `yaml:"alertmanager_servers,omitempty"`
}
type GlobalOptions struct {
User string `yaml:"user,omitempty" default:"tidb"`
Group string `yaml:"group,omitempty"`
SSHPort int `yaml:"ssh_port,omitempty" default:"22" validate:"ssh_port:editable"`
//SSHType executor.SSHType `yaml:"ssh_type,omitempty" default:"builtin"`
TLSEnabled bool `yaml:"enable_tls,omitempty"`
DeployDir string `yaml:"deploy_dir,omitempty" default:"deploy"`
DataDir string `yaml:"data_dir,omitempty" default:"data"`
LogDir string `yaml:"log_dir,omitempty"`
//ResourceControl meta.ResourceControl `yaml:"resource_control,omitempty" validate:"resource_control:editable"`
OS string `yaml:"os,omitempty" default:"linux"`
Arch string `yaml:"arch,omitempty"`
Custom interface{} `yaml:"custom,omitempty" validate:"custom:ignore"`
}
type Manager struct {
sysName string
specManager *SpecManager
//bindVersion spec.BindVersion
//logger *logprinter.Logger
}
type SpecManager struct {
base string
newMeta func() Metadata
}
func (s *SpecManager) NewMetadata() Metadata {
return s.newMeta()
}
func (m *Manager) meta(name string) {
metadata := m.specManager.NewMetadata()
fmt.Println(metadata)
}
func main() {
var cm *Manager
cm.meta("tidb-test")
}
报错如下所示
