fix(core): Add a new parameter worker_event_max_payload to kong.conf (#11214)

* With a hard-coded payload size, for some use cases like uploading a big
OpenAPI spec in DevPortal or updating a big config entry for plugins,
they can not work as expected. With the new parameter, the user can
decide the payload size to meet their needs.

In this PR, a new parameter, `worker_events_max_payload` is added, which
allows to specify the payload size the `worker_events` lib can accept.
The default size is 64k, and the max allowed to set is 16M Bytes.

The corresponding PR for `worker_events` lib is [#37](Kong/lua-resty-events#37)

FTI-4963

* add changelog entry

* Update kong.conf.default

Co-authored-by: Datong Sun <[email protected]>

* add test case and bump lua-resty-events

* correct the default value, and add an entry for bumping the version of lua-resty-events

* 1. append PR number to the changelog entry of lua-resty-events
2. correct the spec test
3. style

* Update CHANGELOG.md

---------

Co-authored-by: Datong Sun <[email protected]>
Co-authored-by: Chrono <[email protected]>

Author: 3 people

.requirements

@@ -7,7 +7,7 @@ PCRE=8.45
 
 LUA_KONG_NGINX_MODULE=4d19e8d19c6dbc07eba5cf6f5ebacad95266f928 # 0.6.0
 LUA_RESTY_LMDB=951926f20b674a0622236a0e331b359df1c02d9b # 1.3.0
-LUA_RESTY_EVENTS=2f6fa23eb3d0b76a3b35fd915711200e90bc6732 # 0.1.6
+LUA_RESTY_EVENTS=8448a92cec36ac04ea522e78f6496ba03c9b1fd8 # 0.2.0
 LUA_RESTY_WEBSOCKET=60eafc3d7153bceb16e6327074e0afc3d94b1316 # 0.4.0
 ATC_ROUTER=72cc8fddeac024c54c9c1fa5a25c28a72d79080e # 1.1.0
 

CHANGELOG.md

@@ -151,9 +151,10 @@
   [#11099](https://github.com/Kong/kong/pull/11099)
 - Bumped kong-lapis from 1.8.3.1 to 1.14.0.2
   [#10841](https://github.com/Kong/kong/pull/10841)
-- Bumped lua-resty-events from 0.1.4 to 0.1.6
+- Bumped lua-resty-events from 0.1.4 to 0.2.0
   [#10883](https://github.com/Kong/kong/pull/10883)
   [#11083](https://github.com/Kong/kong/pull/11083)
+  [#11214](https://github.com/Kong/kong/pull/11214)
 - Bumped lua-resty-session from 4.0.3 to 4.0.4
   [#11011](https://github.com/Kong/kong/pull/11011)
 - Bumped OpenSSL from 1.1.1t to 3.1.1

kong.conf.default

@@ -269,6 +269,7 @@
                                  # Similarly to `error_template_html`, the template
                                  # is required to contain one single `%s` placeholder for
                                  # the error message.
+
 #------------------------------------------------------------------------------
 # HYBRID MODE
 #------------------------------------------------------------------------------

kong/conf_loader/init.lua

@@ -358,6 +358,8 @@ local CONF_PARSERS = {
     },
   },
 
+  worker_events_max_payload = { typ = "number" },
+
   upstream_keepalive_pool_size = { typ = "number" },
   upstream_keepalive_max_requests = { typ = "number" },
   upstream_keepalive_idle_timeout = { typ = "number" },

kong/global.lua

@@ -178,21 +178,31 @@ function _GLOBAL.init_worker_events()
 
   -- `kong.configuration.prefix` is already normalized to an absolute path,
   -- but `ngx.config.prefix()` is not
-  local prefix = configuration
-                 and configuration.prefix
-                 or require("pl.path").abspath(ngx.config.prefix())
+  local prefix = configuration and
+                 configuration.prefix or
+                 require("pl.path").abspath(ngx.config.prefix())
 
-  local sock = ngx.config.subsystem == "stream"
-               and "stream_worker_events.sock"
-               or "worker_events.sock"
+  local sock = ngx.config.subsystem == "stream" and
+               "stream_worker_events.sock" or
+               "worker_events.sock"
 
   local listening = "unix:" .. prefix .. "/" .. sock
 
+  local max_payload_len = configuration and
+                          configuration.worker_events_max_payload
+
+  if max_payload_len and max_payload_len > 65535 then   -- default is 64KB
+    ngx.log(ngx.WARN,
+            "Increasing 'worker_events_max_payload' value has potential " ..
+            "negative impact on Kong's response latency and memory usage")
+  end
+
   opts = {
     unique_timeout = 5,     -- life time of unique event data in lrucache
     broker_id = 0,          -- broker server runs in nginx worker #0
     listening = listening,  -- unix socket for broker listening
     max_queue_len = 1024 * 50,  -- max queue len for events buffering
+    max_payload_len = max_payload_len,  -- max payload size in bytes
   }
 
   worker_events = require "resty.events.compat"

kong/templates/kong_defaults.lua

@@ -45,6 +45,7 @@ cluster_dp_labels = NONE
 lmdb_environment_path = dbless.lmdb
 lmdb_map_size = 2048m
 mem_cache_size = 128m
+worker_events_max_payload = 65535
 ssl_cert = NONE
 ssl_cert_key = NONE
 client_ssl = off

spec/02-integration/07-sdk/06-worker_events_spec.lua

@@ -0,0 +1,123 @@
+local helpers = require "spec.helpers"
+
+local worker_events_mock = [[
+  server {
+    server_name example.com;
+    listen %d;
+
+    location = /payload {
+      content_by_lua_block {
+        local SOURCE = "foo"
+        local EVENT  = ngx.var.http_payload_type
+
+        local worker_events = kong.worker_events
+        local payload_received
+
+        local function wait_until(validator, timeout)
+          local deadline = ngx.now() + (timeout or 5)
+          local res
+          repeat
+            worker_events.poll()
+            res = validator()
+          until res or ngx.now() >= deadline
+          return res
+        end
+
+        -- subscribe
+        local ok, err = worker_events.register(function(data)
+          payload_received = data
+        end, SOURCE, EVENT)
+
+        -- when payload is a string
+        local PAYLOAD = string.rep("X", %d)
+
+        -- when payload is a table
+        if EVENT == "table" then
+          PAYLOAD = {
+            foo = "bar",
+            data = PAYLOAD,
+          }
+        end
+
+        local ok, err = worker_events.post(SOURCE, EVENT, PAYLOAD)
+        if not ok then
+          ngx.status = ngx.HTTP_INTERNAL_SERVER_ERROR
+          ngx.say("post failed, err: " .. err)
+          return
+        end
+
+        assert(wait_until(function()
+          if EVENT == "string" then
+            return PAYLOAD == payload_received
+          else
+            return require("pl.tablex").deepcompare(PAYLOAD, payload_received)
+          end
+        end, 1))
+
+        ngx.status = ngx.HTTP_OK
+        ngx.say("ok")
+      }
+    }
+  }
+]]
+
+
+local max_payloads = { 60 * 1024, 140 * 1024, }
+
+
+for _, max_payload in ipairs(max_payloads) do
+  local business_port = 34567
+  local payload_size = 70 * 1024
+
+  local fixtures = {
+    http_mock = {
+      worker_events = string.format(worker_events_mock,
+                                    business_port, payload_size)
+    },
+  }
+
+  local size_allowed = max_payload > payload_size
+  local less_or_greater = size_allowed and ">" or "<"
+
+  describe("worker_events [when max_payload " .. less_or_greater .. " payload_size]", function()
+    local strategy = "off"
+    local test_cases = {"string", "table", }
+
+    lazy_setup(function()
+      assert(helpers.start_kong({
+        database   = strategy,
+        nginx_conf = "spec/fixtures/custom_nginx.template",
+        worker_events_max_payload = max_payload,
+      }, nil, nil, fixtures))
+    end)
+
+    lazy_teardown(function ()
+      assert(helpers.stop_kong())
+    end)
+
+    for _, payload_type in ipairs(test_cases) do
+      it("max_payload = " .. max_payload .. ", type = " .. payload_type, function()
+
+        local res = helpers.proxy_client(nil, business_port):get(
+          "/payload", {
+          headers = {
+            host = "example.com",
+            payload_type = payload_type,
+          }
+        })
+
+        local status_code = 200
+        local msg = "ok"
+
+        if not size_allowed then
+          status_code = 500
+          msg = "post failed, err: " ..
+                "failed to publish event: payload exceeds the limitation (".. max_payload .. ")"
+        end
+
+        local body = assert.res_status(status_code, res)
+        assert.equal(body, msg)
+      end)
+    end
+  end)
+end