add relay proxy

pkg/handler/relay/metadata.go

@@ -0,0 +1,41 @@
+package relay
+
+import (
+	"strings"
+	"time"
+
+	"github.com/go-gost/gost/pkg/auth"
+	md "github.com/go-gost/gost/pkg/metadata"
+)
+
+type metadata struct {
+	authenticator auth.Authenticator
+	readTimeout   time.Duration
+	retryCount    int
+}
+
+func (h *relayHandler) parseMetadata(md md.Metadata) (err error) {
+	const (
+		authsKey    = "auths"
+		readTimeout = "readTimeout"
+		retryCount  = "retry"
+	)
+
+	if v, _ := md.Get(authsKey).([]interface{}); len(v) > 0 {
+		authenticator := auth.NewLocalAuthenticator(nil)
+		for _, auth := range v {
+			if s, _ := auth.(string); s != "" {
+				ss := strings.SplitN(s, ":", 2)
+				if len(ss) == 1 {
+					authenticator.Add(ss[0], "")
+				} else {
+					authenticator.Add(ss[0], ss[1])
+				}
+			}
+		}
+		h.md.authenticator = authenticator
+	}
+	h.md.readTimeout = md.GetDuration(readTimeout)
+	h.md.retryCount = md.GetInt(retryCount)
+	return
+}