Nginx + lua-nginx, get ssl_session_id (no replies)

Hi!

I'm trying to modify one of auth modules for nginx and I need to get content of either ssl_session_id or any other ssl_* variables with uniq client id to identify connection. But I've got a problems with accessing to this variables from lua.

For testing purposes I'm using self-signed ssl cert.

ngx.log(ngx.DEBUG, "session_id=", ngx.var.ssl_session_id) prints "nil" in the logs. How can I get access to this variable?

lua script is called with access_by_lua directive.

Thanks in advance!

P.S. If I do "set $test_session_id $ssl_session_id;" in config, test_session_id var is also empty.

Best regards,
Vladimir Smirnov.