[SR-Users] Re: How to check for presence of a file from a route? (Or any other way to tell kamailio not to accept new calls)

On 13.11.23 11:17, Benoit Panizzon via sr-users wrote:

Hi

I'm still looking for a better way to tell Kamailio that we want to enter 'maintenance' and STAY in maintenance after a restart.

Maintenance is: Reject all messages without totag with 503 to prevent creating new dialogues.

I could use a shared pv and the use kamcmd pv.shvSet to toggle it.

But when kamailio is restarted, that pv is also reset to it's initial state. Not good, if I want to make sure the node stays in maintenance mode after a restart as for example after pushing a config change via ansible.

So what comes to my mind is to check for the presence of a file.

something like:

route[CHECK_MAINTENANCE] { if (!has_totag() && is_method("INVITE")) { if (file_exist("/etc/kamailio/maintenance.flag")) { xlog("L_ERR", "Maintenance flag present! Rejecting INVITE\n"); t_send_reply("503", "Maintenance mode - no new calls accepted"); exit; } } }

I would really avoid checking/reading a file for every new sip call, especially on production system with decent volume of calls. But if suits your needs and system, look at corex module, there is a function to read the content of a file.

I would rather find a solution where the state is kept in memory, like still using $shv(...) and change kamailio.cfg to init in maintenance mode via pv parameter which can set $shv(...) at startup, or using htable with database backend that loads at startup.

Cheers, Daniel