Lua Nginx Redis get requested domain? -

so right have piece of lovely code

server {     listen 80;      location /{         set $target '';         access_by_lua '             local key = ngx.var.http_host             if not key                 ngx.log("no request url found")                 return ngx.exit(400)             end              local redis = require "resty.redis"             local red = redis:new()              red:set_timeout(1000) -- 1 second              local ok, err = red:connect("<server_ip>", <server_port>)             if not ok                 ngx.log("failed connect reddis server")                 return ngx.exit(500)             end              local res, err = red:auth("<pass>")             if not res                 ngx.say("failed authenticate redis server")                 return ngx.exit(500)             end              local host, err = red:get(key)             if not host                 ngx.log("failed retrieve redis key")                 return ngx.exit(500)             end              if host == ngx.null                 ngx.log("no host found")                 return ngx.exit(400)             end              ngx.var.target = host         ';          proxy_pass http://$target;     } } 

so in redis have key set domain name example.com , have value set backend ip or url in case google.com

now when request comes through plan whatever url user put in, search redis key , value, value , pass onto proxy_pass

am doing wrong?

i have installed nginx-extras , using debian 8