[SR-Users] Re: making HTTP requests in stateless redirects

I didn't test this, but why are you calling t_newtran(); if you only want to send the 300 response? On Apr 8, 2024 18:12, Sergio Charrua via sr-users < sr-users(a)lists.kamailio.org&gt; wrote: Hi all! For testing purposes, while I am waiting for the ST/SH REST API to be available from other teams, I developed a small python REST API that returns a mockup of a JSON object with some of the required values. The kamailio script, completely stateless as I do not need to keep track of the sessions, iterates through one of the JSON branches and adds the destination URLs to the Contact header and replies a SIP 300 Multiple Choices. This works: the UAC does receive the SIP response with the Contacts , but it also receives a SIP 500 error message right after, and I can't figure out why. And i bet this is simple to solve.... Any clue? I'm aware I'm not processing ACK messages, but the sl_send_reply 403 should do the trick right? ... at least while testing.... Also, as this is a stateless script, is there another way of using async http or making http requests to a REST API without having to use TM Module? Thanks in advance. The kamailio script is has follows: #!KAMAILIO /* add API http timeout */ #!define HTTP_API_TIMEOUT 5000 #!define HTTP_API_ROUTING_ENDPOINT "http://some_python_rest_api/get_route" ### LOG Levels: 3=DBG, 2=INFO, 1=NOTICE, 0=WARN, -1=ERR debug=4 log_stderror=no memdbg=5 memlog=5 log_facility=LOG_LOCAL0 log_prefix="{$mt $hdr(CSeq) $ci} " /* number of SIP routing processes */ children=2 /* set paths to location of modules */ loadmodule "tm.so" loadmodule "jsonrpcs.so" loadmodule "kex.so" loadmodule "corex.so" loadmodule "sl.so" loadmodule "db_mysql.so" loadmodule "rr.so" loadmodule "pv.so" loadmodule "maxfwd.so" loadmodule "ipops.so" loadmodule "textops.so" loadmodule "siputils.so" loadmodule "xlog.so" loadmodule "sanity.so" loadmodule "ctl.so" loadmodule "cfg_rpc.so" loadmodule "uac.so" loadmodule "counters.so" loadmodule "http_async_client.so" loadmodule "jansson.so" loadmodule "usrloc.so" /* listen addresses */ listen=udp:10.20.0.2:5060 listen=udp:10.20.0.2:5062 advertised_address="10.20.0.2"; # ----- http_async_client params ----- modparam("http_async_client", "workers", HTTP_ASYNC_CLIENT_WORKERS) modparam("http_async_client", "connection_timeout", 2000) request_route { #route(HANDLE_DMQ); route(HANDLE_OPTIONS); if (is_method("INVITE")) { xlog("L_INFO","MAIN - calling TO_CARRIER"); route(TO_CARRIER); exit; } else{ sl_send_reply("401","UNAUTHORIZED"); } } route[TO_CARRIER]{ xlog("L_INFO","TO_CARRIER - calling RELAY_API"); route(RELAY_API); #Route relay xlog("L_INFO","TO_CARRIER - return"); return; } # Relay request using the API (response) route[RELAY_API_RESPONSE] { xlog("L_INFO","RELAY_API_RESPONSE - got response from REST API"); if ($http_ok==1 && $http_rs==200) { xlog("L_INFO","RELAY_API_RESPONSE - HTTP RESPONSE: $http_rb\n"); if (jansson_get("json", $http_rb, "$var(json)")) { xlog("L_INFO","RELAY_API_RESPONSE - JSON = $var(json)"); $var(count) = 0; jansson_array_size("routes", $var(json), "$var(size)"); xlog("L_INFO","RELAY_API_RESPONSE - jansson_array_size"); while ( $var(count) < $var(size) ){ jansson_get("routes[$var(count)].headers.to.uri", $var(rtjson), "$var(v)"); xlog("L_INFO","JSON - routes[$var(count)] - $var(v)"); #$(avp(mycontacts)[$var(count)]) = $avp(mycontacts) + $var(v) + "\r\n"; $avp(mycontacts) = $avp(mycontacts) + $var(v) + ";"; *append_to_reply("Contact: <" + $var(v) +">"+ "\r\n"); /* ---- IS THERE A BETTER ?? ..... */* $var(count) = $var(count) + 1; } xlog("L_INFO","RELAY_API_RESPONSE - RELAY"); xlog("L_INFO","MAIN - calling REPLY_302"); route(REPLY_302); return; } } send_reply(500, "API Not Available - http response = $http_rs $http_ok"); exit; } route[RELAY_API] { xlog("L_INFO","RELAY_API - from_ip $si:$sp from_number $fU to_number $ru"); $http_req(all) = $null; $http_req(suspend) = 1; $http_req(timeout) = HTTP_API_TIMEOUT; $http_req(method) = "POST"; $http_req(hdr) = "Content-Type: application/json"; jansson_set("string","from_ip",$si, "$var(http_routing_query)"); jansson_set("string","from_port",$sp, "$var(http_routing_query)"); jansson_set("string","from_number",$fU, "$var(http_routing_query)"); jansson_set("string","to_number",$ru , "$var(http_routing_query)"); xlog("L_INFO","RELAY_API - API ASYNC ROUTING REQUEST: $var(http_routing_query)\n"); $http_req(body) = $var(http_routing_query); t_newtran(); http_async_query(HTTP_API_ROUTING_ENDPOINT, "RELAY_API_RESPONSE"); xlog("L_INFO","RELAY_API - Waiting for Response"); } route[REPLY_302] { # Sends a 300 Multiple Choices back to the proxy that requested the routing lookup xlog("L_INFO","REPLY_302 - send reply"); sl_send_reply("300", "Multiple Choices"); xlog("L_INFO","REPLY_302 - exit"); exit; } route[HANDLE_OPTIONS]{ if(is_method("OPTIONS")) { sl_send_reply(200, "OK"); exit; } if ($fU=="ping") { sl_send_reply("200","OK"); exit; } } SNGrep output: 1 - INVITE from UAC to Kamailio INVITE sip:918228990@10.20.0.2 SIP/2.0 Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4 Max-Forwards: 70 From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891 To: <sip:918228990@10.20.0.2> Contact: <sip:anonymous@10.20.0.1:5063> Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063 CSeq: 102 INVITE User-Agent: SIPp Date: Mon, 08 Apr 2024 15:09:51 GMT Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE Supported: replaces, timer Content-Type: application/sdp Content-Length: 270 v=0 o=root 2021555890 2021555890 IN IP4 10.20.0.1 s=SIPp c=IN IP4 10.20.0.1 t=0 0 m=audio 18422 RTP/AVP 8 0 101 a=rtpmap:8 PCMA/8000 a=rtpmap:0 PCMU/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=maxptime:150 a=sendrecv 2 - Reply from Kamailio to UAC SIP/2.0 100 trying -- your call is important to us Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4 From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891 To: <sip:918228990@10.20.0.2> Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063 CSeq: 102 INVITE Server: kamailio (5.7.4 (x86_64/linux)) Content-Length: 0 3 - SIP 300 Multiple Choices from Kamailio to UAC SIP/2.0 300 Multiple Choices Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4 From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891 To: <sip:918228990@10.20.0.2 Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063 CSeq: 102 INVITE Contact: <sip:sip:918228990@10.20.0.2@sip.domain.io> Contact: <sip:+351sip:918228990@10.20.0.2@10.20.0.3> Server: kamailio (5.7.4 (x86_64/linux)) Content-Length: 0 4 - SIP 500 from Kamailio to UAC SIP/2.0 500 I'm terribly sorry, server error occurred (1/TM) Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4 From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891 To: <sip:918228990@10.20.0.2 Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063 CSeq: 102 INVITE Server: kamailio (5.7.4 (x86_64/linux)) Content-Length: 0 5 - ACK from UAC to Kamailio ACK sip:918228990@10.20.0.2 SIP/2.0 Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4 Max-Forwards: 70 From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891 To: <sip:918228990@10.20.0.2 Contact: <sip:anonymous@10.20.0.1:5063> Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063 CSeq: 102 ACK User-Agent: SIPp Content-Length: 0 and continues with ACK and repeating SIP 500 above.... *Sérgio Charrua* .