Nginx Lua In Action

                        local user = ngx.var.args or ngx.exit(ngx.HTTP_BAD_REQUEST)
local expire = tonumber(ngx.var.exptime) or 86400

user = user:lower():gsub('^([^@]+)@56.com$', '%1') -- lowercase, user@56.com => user

if ( not util.validate_userid(user) ) then
    ngx.status = ngx.HTTP_NOT_FOUND
    ngx.say("user is banned")
    ngx.exit(ngx.HTTP_OK)
end

local c,err = cache:new(user)
if not c then
    log(ngx.EMERG, 'failed to new cache => ' .. user .. ':' .. err)
    ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
end
local res,flags,err = c:get()
local cache_status = "HIT"