fix(pdk): response send function should ignore transfer-encoding correctly

changelog/unreleased/kong/pdk-response-send-remove-transfer-encoding.yml

@@ -0,0 +1,3 @@
+message: Fix an issue that when using kong.response.exit, the Transfer-Encoding header set by user is not removed
+type: bugfix
+scope: PDK

kong/pdk/response.lua

@@ -660,7 +660,6 @@ local function new(self, major_version)
     local has_content_length
     if headers ~= nil then
       for name, value in pairs(headers) do
-        ngx.header[name] = normalize_multi_header(value)
         local lower_name = lower(name)
         if lower_name == "transfer-encoding" or lower_name == "transfer_encoding" then
           self.log.warn("manually setting Transfer-Encoding. Ignored.")

spec/03-plugins/27-aws-lambda/99-access_spec.lua

@@ -150,6 +150,12 @@ for _, strategy in helpers.each_strategy() do
         service     = null,
       }
 
+      local route24 = bp.routes:insert {
+        hosts       = { "lambda24.com" },
+        protocols   = { "http", "https" },
+        service     = null,
+      }
+
       bp.plugins:insert {
         name     = "aws-lambda",
         route    = { id = route1.id },
@@ -463,6 +469,19 @@ for _, strategy in helpers.each_strategy() do
         }
       }
 
+      bp.plugins:insert {
+        name     = "aws-lambda",
+        route    = { id = route24.id },
+        config                 = {
+          port                 = 10001,
+          aws_key              = "mock-key",
+          aws_secret           = "mock-secret",
+          aws_region           = "us-east-1",
+          function_name        = "functionWithTransferEncodingHeader",
+          is_proxy_integration = true,
+        }
+      }
+
       fixtures.dns_mock:A({
         name = "custom.lambda.endpoint",
         address = "127.0.0.1",
@@ -1148,6 +1167,24 @@ for _, strategy in helpers.each_strategy() do
         assert.equals("https", req.vars.scheme)
       end)
 
+      it("#test2 works normally by removing transfer encoding header when proxy integration mode", function ()
+        proxy_client:set_timeout(3000)
+        assert.eventually(function ()
+          local res = assert(proxy_client:send({
+            method  = "GET",
+            path    = "/get",
+            headers = {
+              ["Host"] = "lambda24.com"
+            }
+          }))
+
+          assert.res_status(200, res)
+          assert.is_nil(res.headers["Transfer-Encoding"])
+          assert.is_nil(res.headers["transfer-encoding"])
+
+          return true
+        end).with_timeout(3).is_truthy()
+      end)
     end)
 
     describe("AWS_REGION environment is set", function()

spec/fixtures/aws-lambda.lua

@@ -57,6 +57,9 @@ local fixtures = {
                     elseif string.match(ngx.var.uri, "functionEcho") then
                       require("spec.fixtures.mock_upstream").send_default_json_response()
 
+                    elseif string.match(ngx.var.uri, "functionWithTransferEncodingHeader") then
+                      ngx.say("{\"statusCode\": 200, \"headers\": { \"Transfer-Encoding\": \"chunked\", \"transfer-encoding\": \"chunked\"}}")
+
                     elseif type(res) == 'string' then
                       ngx.header["Content-Length"] = #res + 1
                       ngx.say(res)

t/01-pdk/08-response/11-exit.t

@@ -4,7 +4,7 @@ use Test::Nginx::Socket::Lua;
 use Test::Nginx::Socket::Lua::Stream;
 do "./t/Util.pm";
 
-plan tests => repeat_each() * (blocks() * 4) + 11;
+plan tests => repeat_each() * (blocks() * 4) + 12;
 
 run_tests();
 
@@ -1128,7 +1128,7 @@ finalize stream session: 200
 
 
 
-=== TEST 18: response.exit() does not set transfer-encoding from headers
+=== TEST 44: response.exit() does not set transfer-encoding from headers
 --- http_config eval: $t::Util::HttpConfig
 --- config
     location = /t {
@@ -1148,6 +1148,7 @@ GET /t
 --- response_body
 test
 --- response_headers
+! Transfer-Encoding
 Content-Length: 5
 X-test: test
 --- error_log