feat: support tls for etcd client (#1390)

* feat: support tls for etcd client

* chore: fix typo

* refactor: rename TrustedCAFile to CACertFile

* docs: add comments

* fix: missing tls registration

* feat: add InsecureSkipVerify config for testing

core/discov/subscriber.go

@@ -5,6 +5,7 @@ import (
 	"sync/atomic"
 
 	"github.com/tal-tech/go-zero/core/discov/internal"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/core/syncx"
 )
 
@@ -58,10 +59,17 @@ func Exclusive() SubOption {
 	}
 }
 
-// WithSubEtcdAccount customizes the Subscriber with given etcd username/password.
+// WithSubEtcdAccount provides the etcd username/password.
 func WithSubEtcdAccount(user, pass string) SubOption {
 	return func(sub *Subscriber) {
-		internal.AddAccount(sub.endpoints, user, pass)
+		RegisterAccount(sub.endpoints, user, pass)
+	}
+}
+
+// WithSubEtcdTLS provides the etcd CertFile/CertKeyFile/CACertFile.
+func WithSubEtcdTLS(certFile, certKeyFile, caFile string, insecureSkipVerify bool) SubOption {
+	return func(sub *Subscriber) {
+		logx.Must(RegisterTLS(sub.endpoints, certFile, certKeyFile, caFile, insecureSkipVerify))
 	}
 }