Kamailio by example - KEMI with Python

Python

Note: Read the official docs to get the most updated information.

As we saw in the KEMI intro, we just need load the module, set the load path, and the cfgengine:

#!defenvs KAMA_LISTEN
listen=KAMA_LISTEN
auto_aliases=no

loadmodule "sl"
modparam("sl", "bind_tm", 0)

loadmodule "app_python3s"
modparam("app_python3s", "load", "/etc/kamailio/cfg/1-kemi/100-kemi-py.py")

cfgengine "python"

import KSR as KSR

def ksr_request_route():
    KSR.sl.sl_send_reply(200, "Hello, py World!")

Selecting an Interpreter

Since we know how to use a pre-processing directive, we can now use a single file file global parameters/modules load another file for routing, using include_file "/etc/kamailio/tmp/route.inc.cfg"

├── shared
│  └── route.inc.cfg # shared routing include
└── kemi
    ├── kemi.inc.cfg # routing with native config
    ├── kemi.lua     # routing with lua
    ├── kemi.cfg     # main file
    └── kemi.py      # routing with python

How to test: Check the kamalab to prepare your lab.

Now we can select the routing language with -k language

# kamalab ❯
./kamalab -r py
# select kemi
# Listening on
#              udp: 127.0.0.2 [127.0.0.2]:5060
#              tcp: 127.0.0.2 [127.0.0.2]:5060
# Aliases:

In another terminal let’s send OPTIONS to the server:

# >
sipexer 127.0.0.2
# ...
# OPTIONS sip:127.0.0.2:5060 SIP/2.0
# ...
# SIP/2.0 200 Hello, py World!
# ...

We see that:

• We get the 200 Hello, py World! if we select kemi with py, but we can easily test with different languages.

Resources

• Wiki Pseudo-Variables Cookbook
• NickvsNetworking