support customize signRequestFunc for sc client (#66)

* Update options.go

support customize signRequestFunc  for sc client

* Update client.go

support customize signRequestFunc for sc-client

client.go

@@ -77,8 +77,8 @@ type Client struct {
 	watchers map[string]bool
 	mutex    sync.Mutex
 	// addresspool mutex
-	poolMutex    sync.Mutex
-	wsDialer *websocket.Dialer
+	poolMutex sync.Mutex
+	wsDialer  *websocket.Dialer
 	// record the websocket connection with the service center
 	conns    map[string]*websocket.Conn
 	revision string
@@ -162,6 +162,10 @@ func (c *Client) buildClientOptions(opt Options) *httpclient.Options {
 	if !opt.EnableAuth {
 		return options
 	}
+	if opt.SignRequest != nil {
+		options.SignRequest = opt.SignRequest
+		return options
+	}
 	// when the authentication is enabled, the token of automatic renewal is added to the request header
 	if opt.TokenExpiration == 0 {
 		opt.TokenExpiration = DefaultTokenExpiration

options.go

@@ -3,6 +3,7 @@ package sc
 import (
 	"context"
 	"crypto/tls"
+	"net/http"
 	"time"
 
 	"github.com/go-chassis/cari/rbac"
@@ -22,6 +23,7 @@ type Options struct {
 	AuthUser        *rbac.AuthUser
 	AuthToken       string
 	TokenExpiration time.Duration
+	SignRequest     func(*http.Request) error
 }
 
 // CallOptions is options when you call a API