Duplicate access_by_lua calls

rpaprocki · 2015-02-07T13:23:53+00:00

Hello! On Thu, Feb 5, 2015 at 12:12 PM, Lord Nynex wrote: > error_page 502 @502; > > location @502 { > content_by_lua ' > local redis = req...

Duplicate access_by_lua calls

rpaprocki

Hello!

We have a simple nginx config (using the latest stable openresty release) as follows:

location / {

default_type text/html;

root /var/www/html;

access_by_lua ' --unrelated code';

}

I've noticed that the code run in the access_by_lua directive seems to run twice when I request 'http://example.com/', I'm assuming because there's an internal rewrite to /index.html. This behavior also appears when the access_by_lua directive is moved to the server{} block. I also noticed this type of behavior with a try_files setup (for a WordPress installation). Is it possible to detect and/or prevent this duplicate execution for local internal rewrites? I noted that this does not occur with reverse proxy setups, because there is no internal rewrite for a default index file. Thanks in advance!

agentzh

Hello!

On Fri, Feb 6, 2015 at 9:23 PM, Robert Paprocki wrote:
> I've noticed that the code run in the access_by_lua directive seems to run
> twice when I request 'http://example.com/', I'm assuming because there's an
> internal rewrite to /index.html.

This is the expected behavior with nginx internal redirects. When
internal redirects happen, access phase handlers (and rewrite phase
handlers and etc) always run again. Not just access_by_lua, but also
access-phase handlers registered by any other nginx C modules.

Well, we could expose a simple Lua API based on the "r->uri_changes"
field on the C land so that the Lua programmers can explicitly check
whether it is the first run or not. Patches welcome :)

Regards,
-agentzh