diff --git a/main.lua b/main.lua
index 60fbb8e..9f2049d 100644
--- a/main.lua
+++ b/main.lua
@@ -12,6 +12,12 @@ require('util')
 
 ctx:loadFromConfig(config.loadConfigFile())
 
-return function()
-    ctx:onRequest()
-end
+return {
+    init=function ()
+        -- validate config and print out errors
+        config.loadConfigFile()
+    end,
+    access=function()
+        ctx:onRequest()
+    end
+}
diff --git a/nginx.conf b/nginx.conf
index 81904be..4b6e8bf 100644
--- a/nginx.conf
+++ b/nginx.conf
@@ -1,4 +1,8 @@
-  server {
+init_by_lua_block {
+  require("aproxy.main").init()
+}
+
+server {
     listen 80;
     lua_code_cache off;
 
@@ -7,9 +11,9 @@
 
       # must happen before proxy_pass
       access_by_lua_block {
-        require("aproxy.main")()
+        require("aproxy.main").access()
       }
 
       proxy_pass http://localhost:9999;
     }
-  }
+}