Exchanging variables between LUA directives in NGINX

Question

I am using HttpLuaModule for my NGINX server. I want to ask if it is possible to recognize variable in different directives of this module. For example

 init_by_lua ' local global_var = 5 ' ;
 some config ;
 set_by_lua ' print(global_var) ' ;

How is that possible with NGINX and LUA module ?

Answer 1

If you want global_var to be global, don't declare it as local.

From a quick look at NGINX's docs, init_by_lua and set_by_lua work on the same global Lua state and so you'll be able to make them talk if you use global variables. Local variables set in init_by_lua will be lost.

So, it should work if you just remove local in init_by_lua.