add auth interceptors

interceptors/auth/token.go

@@ -0,0 +1,19 @@
+package auth
+
+import (
+	"context"
+
+	grpc_auth "github.com/grpc-ecosystem/go-grpc-middleware/auth"
+)
+
+type TokenValidator func(ctx context.Context, token string) (context.Context, error)
+
+func makeTokenAuthFunc(v TokenValidator) grpc_auth.AuthFunc {
+	return func(ctx context.Context) (context.Context, error) {
+		a, err := grpc_auth.AuthFromMD(ctx, "bearer")
+		if err != nil {
+			return ctx, err
+		}
+		return v(ctx, a)
+	}
+}