feat(healthcheck) support setting the events module

this is wip

lib/resty/healthcheck.lua

@@ -33,7 +33,6 @@ local ipairs = ipairs
 local cjson = require("cjson.safe").new()
 local table_insert = table.insert
 local table_remove = table.remove
-local worker_events = require("resty.worker.events")
 local resty_lock = require ("resty.lock")
 local re_find = ngx.re.find
 local bit = require("bit")
@@ -43,6 +42,11 @@ local ngx_worker_pid = ngx.worker.pid
 local ssl = require("ngx.ssl")
 local resty_timer = require "resty.timer"
 
+
+local RESTY_EVENTS_VER = "0.1.0"
+local RESTY_WORKER_EVENTS_VER = "0.3.3"
+
+
 local new_tab
 local nkeys
 local is_array
@@ -83,6 +87,32 @@ do
   end
 end
 
+
+local worker_events
+--- This function loads the worker events module received as arg. It will throw
+-- error() if it is not possible to load the module.
+local function load_events_module(module_name)
+  if module_name == "resty.worker.events" then
+    worker_events = require("resty.worker.events")
+    assert(worker_events, "could not load lua-resty-worker-events")
+    assert(worker_events._VERSION == RESTY_WORKER_EVENTS_VER,
+          "unsupported lua-resty-worker-events version")
+    assert(worker_events.configured(), "please configure the " ..
+          "'lua-resty-worker-events' module before using 'lua-resty-healthcheck'")
+
+  elseif module_name == "resty.events" then
+    worker_events = require("resty.events.compat")
+    assert(worker_events, "could not load lua-resty-events")
+    assert(worker_events._VERSION == RESTY_EVENTS_VER,
+          "unsupported lua-resty-events version")
+
+  else
+    error("unknown events module")
+  end
+
+end
+
+
 -- constants
 local EVENT_SOURCE_PREFIX = "lua-resty-healthcheck"
 local LOG_PREFIX = "[healthcheck] "
@@ -1334,6 +1364,7 @@ local defaults = {
   name = NO_DEFAULT,
   shm_name = NO_DEFAULT,
   type = NO_DEFAULT,
+  events_module = "resty.worker.events",
   checks = {
     active = {
       type = "http",
@@ -1437,8 +1468,7 @@ end
 -- @return checker object, or `nil + error`
 function _M.new(opts)
 
-  assert(worker_events.configured(), "please configure the " ..
-      "'lua-resty-worker-events' module before using 'lua-resty-healthcheck'")
+  load_events_module(opts.events_module)
 
   local active_type = (((opts or EMPTY).checks or EMPTY).active or EMPTY).type
   local passive_type = (((opts or EMPTY).checks or EMPTY).passive or EMPTY).type

lua-resty-healthcheck-scm-1.rockspec

@@ -14,7 +14,6 @@ description = {
   homepage = "https://github.com/Kong/lua-resty-healthcheck"
 }
 dependencies = {
-  "lua-resty-worker-events == 1.0.0",
   "penlight >= 1.9.2",
   "lua-resty-timer ~> 1",
 }