Nginx (openresty) generating random numbers

Question

I have openresty set up on a server (nginx bundle which includes the lua module) and I'm trying to create a script which has specific odds of setting a cookie on a user's browser. My code looks like this:

    location =/index.php {
        set $random_num 0;

        rewrite_by_lua '

                marth.randomseed(1);
                nvx.var.random_num = math.random(0,3);

        ';

        add_header Set-Cookie "random_num=$random_num; path=/; domain=...com;";
    }

I know my random seed function isn't actually very random, but I figured I'd deal with that later. At the moment I'm just trying to get nginx to set a random number, but doing so yields this error:

2012/07/11 11:27:20 [error] 5492#0: *44 lua handler aborted: runtime error: [string "rewrite_by_lua"]:3: attempt to ind
ex global 'marth' (a nil value)
stack traceback:

Can anyone tell me what I'm doing wrong, and if there's any other way to get a random number in nginx?

just add that "nvx.var.random_num" should actually be ngx – lippea Aug 22 '17 at 06:02 — lippea, Aug 22 '17 at 06:02

score 8 · Accepted Answer · answered Jul 11 '12 at 17:29

8

Based on your error log entry, it appears you have a simple typo.

            marth.randomseed(1);

This should read:

            math.randomseed(1);

answered Jul 11 '12 at 17:29

Michael Hampton

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Wow, and this is what I get for not sleeping – Mediocre Gopher Jul 11 '12 at 17:43
7

Sleep takes a lot of time, but it takes less time than debugging. I recommend sleep. – Michael Hampton Jul 11 '12 at 17:54
2

`sleep 28800` is a good idea. – Janne Pikkarainen Jul 11 '12 at 18:21

Nginx (openresty) generating random numbers

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