lua socket settimeout has no effect

[Sachin Shetty]

Hi,

We are using a http-req lua action to dynamically set some app specific
metadata headers. The lua handler connects to a upstream memcache like
service over tcp to fetch additional metadata.

Functionally everything works ok, but I am seeing that socket.settimeout
has no effect. Irrespective of what I set in settimeout if the upstream
service is unreachable, connect always timesout at 5 seconds, and read
timeout around 10 seconds. It seems like  settimeout has no effect and it
always picks defaults of 5 seconds for connect timeout and 10 seconds for
read timeout.

Haproxy conf call:

http-request lua.get_proxy

Lua code sample:

function get_proxy(txn)
    local sock = core.tcp()
    sock:settimeout(2)
    status, error = sock:connect(gds_host, gds_port)
    if not status then
        core.Alert("1 Error in connecting:" .. key .. ":" .. error)
        return result, "Error: " .. error
    end
    sock:send(key .. "\r\n")
    ....
    ....


core.register_action("get_proxy", { "http-req" }, get_proxy)

Haproxy version:

HA-Proxy version 1.7.8 2017/07/07
Copyright 2000-2017 Willy Tarreau <wi...@haproxy.org>

Build options :
  TARGET  = linux2628
  CPU     = generic
  CC      = gcc
  CFLAGS  = -O2 -g -fno-strict-aliasing -Wdeclaration-after-statement
-fwrapv -DTCP_USER_TIMEOUT=18
  OPTIONS = USE_LINUX_TPROXY=1 USE_ZLIB=1 USE_REGPARM=1 USE_OPENSSL=1
USE_LUA=1 USE_PCRE=1

Default settings :
  maxconn = 2000, bufsize = 16384, maxrewrite = 1024, maxpollevents = 200

Encrypted password support via crypt(3): yes
Built with zlib version : 1.2.7
Running on zlib version : 1.2.7
Compression algorithms supported : identity("identity"),
deflate("deflate"), raw-deflate("deflate"), gzip("gzip")
Built with OpenSSL version : OpenSSL 1.0.1e-fips 11 Feb 2013
Running on OpenSSL version : OpenSSL 1.0.1e-fips 11 Feb 2013
OpenSSL library supports TLS extensions : yes
OpenSSL library supports SNI : yes
OpenSSL library supports prefer-server-ciphers : yes
Built with PCRE version : 8.32 2012-11-30
Running on PCRE version : 8.32 2012-11-30
PCRE library supports JIT : no (USE_PCRE_JIT not set)
Built with Lua version : Lua 5.3.2
Built with transparent proxy support using: IP_TRANSPARENT IPV6_TRANSPARENT
IP_FREEBIND

Available polling systems :
      epoll : pref=300,  test result OK
       poll : pref=200,  test result OK
     select : pref=150,  test result OK
Total: 3 (3 usable), will use epoll.

Available filters :
    [COMP] compression
    [TRACE] trace
    [SPOE] spoe



Thanks
Sachin