lua: Make httpCall to return raw data

docs/root/version_history/current.rst

@@ -35,6 +35,7 @@ Minor Behavior Changes
 * logging: changed default log format to `"[%Y-%m-%d %T.%e][%t][%l][%n] [%g:%#] %v"` and default value of :option:`--log-format-prefix-with-location` to `0`.
 * logging: nghttp2 log messages no longer appear at trace level unless `ENVOY_NGHTTP2_TRACE` is set
   in the environment.
+* lua: changed the response body returned by `httpCall()` API to raw data. Previously, the returned data was string.
 * router: added transport failure reason to response body when upstream reset happens. After this change, the response body will be of the form `upstream connect error or disconnect/reset before headers. reset reason:{}, transport failure reason:{}`.This behavior may be reverted by setting runtime feature `envoy.reloadable_features.http_transport_failure_reason_in_body` to false.
 * router: now consumes all retry related headers to prevent them from being propagated to the upstream. This behavior may be reverted by setting runtime feature `envoy.reloadable_features.consume_all_retry_headers` to false.
 * thrift_proxy: special characters {'\0', '\r', '\n'} will be stripped from thrift headers.

source/extensions/filters/http/lua/lua_filter.cc

@@ -349,7 +349,8 @@ void StreamHandleWrapper::onSuccess(const Http::AsyncClient::Request&,
 
   // TODO(mattklein123): Avoid double copy here.
   if (response->body() != nullptr) {
-    lua_pushstring(coroutine_.luaState(), response->bodyAsString().c_str());
+    lua_pushlstring(coroutine_.luaState(), response->bodyAsString().data(),
+                    response->body()->length());
   } else {
     lua_pushnil(coroutine_.luaState());
   }

test/extensions/filters/http/lua/lua_filter_test.cc

@@ -790,7 +790,10 @@ TEST_F(LuaHttpFilterTest, HttpCall) {
       for key, value in pairs(headers) do
         request_handle:logTrace(key .. " " .. value)
       end
+      request_handle:logTrace(string.len(body))
       request_handle:logTrace(body)
+      request_handle:logTrace(string.byte(body, 5))
+      request_handle:logTrace(string.sub(body, 6, 8))
     end
   )EOF"};
 
@@ -828,9 +831,13 @@ TEST_F(LuaHttpFilterTest, HttpCall) {
 
   Http::ResponseMessagePtr response_message(new Http::ResponseMessageImpl(
       Http::ResponseHeaderMapPtr{new Http::TestResponseHeaderMapImpl{{":status", "200"}}}));
-  response_message->body() = std::make_unique<Buffer::OwnedImpl>("response");
+  const char response[8] = {'r', 'e', 's', 'p', '\0', 'n', 's', 'e'};
+  response_message->body() = std::make_unique<Buffer::OwnedImpl>(response, 8);
   EXPECT_CALL(*filter_, scriptLog(spdlog::level::trace, StrEq(":status 200")));
-  EXPECT_CALL(*filter_, scriptLog(spdlog::level::trace, StrEq("response")));
+  EXPECT_CALL(*filter_, scriptLog(spdlog::level::trace, StrEq("8")));
+  EXPECT_CALL(*filter_, scriptLog(spdlog::level::trace, StrEq("resp")));
+  EXPECT_CALL(*filter_, scriptLog(spdlog::level::trace, StrEq("0")));
+  EXPECT_CALL(*filter_, scriptLog(spdlog::level::trace, StrEq("nse")));
   EXPECT_CALL(decoder_callbacks_, continueDecoding());
   callbacks->onBeforeFinalizeUpstreamSpan(child_span_, &response_message->headers());
   callbacks->onSuccess(request, std::move(response_message));