MINOR: hlua_fcn/mailers: handle timeout mail from mailers section

As the example/lua/mailers.lua script does its best to mimic the c-mailer
implementation, it should support the "timeout mail" directive as well.

This could be backported in 2.8.

doc/lua-api/index.rst

@@ -1198,6 +1198,12 @@ ProxyMailers class
   Each array entry is a name:desc pair where desc represents the full server
   address (including port) as described in haproxy's configuration file.
 
+.. js:attribute:: ProxyMailers.mailservers_timeout
+
+  An integer representing the maximum time in milliseconds to wait for the
+  email to be sent. See "timeout mail" directive from "mailers" section in
+  haproxy configuration file.
+
 .. js:attribute:: ProxyMailers.smtp_hostname
 
   A string containing the hostname to use for the SMTP transaction.

examples/lua/mailers.lua

@@ -30,7 +30,9 @@ local mailqueue = core.queue()
 -- same format used in haproxy config file. It will be passed as it is to
 -- tcp::connect() without explicit port argument. See Socket.connect()
 -- manual for more information.
-function smtp_send_email(server, domain, from, to, data)
+--
+-- The function will abort after <timeout> ms
+function smtp_send_email(server, timeout, domain, from, to, data)
         local ret
         local reason
         local tcp = core.tcp()
@@ -55,6 +57,10 @@ function smtp_send_email(server, domain, from, to, data)
                 end
         end
 
+	if timeout ~= 0 then
+		tcp:settimeout(timeout / 1000)
+	end
+
         if tcp:connect(server) == nil then
                 return false, "Can't connect to \""..server.."\""
         end
@@ -406,6 +412,7 @@ core.register_task(function()
 			for name, mailsrv in pairs(job.mailconf.mailservers) do
 				-- finally, send email to server
 				local ret, reason = smtp_send_email(mailsrv,
+								    job.mailconf.mailservers_timeout,
 								    job.mailconf.smtp_hostname,
 								    job.mailconf.smtp_from,
 								    job.mailconf.smtp_to,

src/hlua_fcn.c

@@ -2134,6 +2134,11 @@ int hlua_proxy_get_mailers(lua_State *L)
 	}
 	lua_settable(L, -3);
 
+	/* mailers timeout (from mailers section) */
+	lua_pushstring(L, "mailservers_timeout");
+	lua_pushinteger(L, px->email_alert.mailers.m->timeout.mail);
+	lua_settable(L, -3);
+
 	/* email-alert myhostname */
 	lua_pushstring(L, "smtp_hostname");
 	lua_pushstring(L, px->email_alert.myhostname);