fix(pdk): fix log serialize upstream_status entry nil bug in subrequest case

changelog/unreleased/kong/fix-log-upstream-status-nil-subrequest.yml

@@ -0,0 +1,4 @@
+message: |
+ **PDK**: Fixed a bug that log serializer will log `upstream_status` as nil in the requests that contains subrequest
+type: bugfix
+scope: PDK

kong/pdk/log.lua

@@ -814,10 +814,7 @@ do
  end
  end
 
- -- The value of upstream_status is a string, and status codes may be
- -- seperated by comma or grouped by colon, according to
- -- the nginx doc: http://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream_status
- local upstream_status = var.upstream_status or ""
+ local upstream_status = var.upstream_status or ctx.buffered_status or ""
 
  local response_source = okong.response.get_source(ongx.ctx)
  local response_source_name = TYPE_NAMES[response_source]

spec/03-plugins/04-file-log/01-log_spec.lua

@@ -247,6 +247,36 @@ for _, strategy in helpers.each_strategy() do
  },
  }
 
+ local route10 = bp.routes:insert {
+ hosts = { "file_logging10.test" },
+ response_buffering = true,
+ }
+
+ bp.plugins:insert({
+ name = "pre-function",
+ route = { id = route10.id },
+ config = {
+ access = {
+ [[
+ kong.service.request.enable_buffering()
+ ]],
+ },
+ }
+ })
+
+ bp.plugins:insert {
+ route = { id = route10.id },
+ name = "file-log",
+ config = {
+ path = FILE_LOG_PATH,
+ reopen = true,
+ custom_fields_by_lua = {
+ new_field = "return 123",
+ route = "return nil", -- unset route field
+ },
+ },
+ }
+
  assert(helpers.start_kong({
  database = strategy,
  nginx_conf = "spec/fixtures/custom_nginx.template",
@@ -337,6 +367,28 @@ for _, strategy in helpers.each_strategy() do
  assert.is_number(log_message.response.size)
  assert.same(nil, log_message.route)
  end)
+ it("correct upstream status when we use response phase", function()
+ local uuid = random_string()
+
+ -- Making the request
+ local res = assert(proxy_client:send({
+ method = "GET",
+ path = "/status/200",
+ headers = {
+ ["file-log-uuid"] = uuid,
+ ["Host"] = "file_logging10.test"
+ }
+ }))
+ assert.res_status(200, res)
+
+ local log_message = wait_for_json_log_entry()
+ assert.same("127.0.0.1", log_message.client_ip)
+ assert.same(uuid, log_message.request.headers["file-log-uuid"])
+ assert.is_number(log_message.request.size)
+ assert.is_number(log_message.response.size)
+ assert.same(nil, log_message.route)
+ assert.same(200, log_message.upstream_status)
+ end)
  end)
 
  it("logs to file #grpc", function()

t/01-pdk/02-log/00-phase_checks.t

@@ -66,7 +66,12 @@ qq{
  },
  response = {
  get_source = function() return "service" end,
- },
+ },
+ service = {
+ response = {
+ get_status = function() return 200 end,
+ },
+ },
  }
  }
  },