app_python3s Module

Daniel-Constantin Mierla

Maxim Sobolev

Anthony Alba

Edited by

Daniel-Constantin Mierla

   Copyright © 2022 kamailio.org
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies

              2.1. Kamailio Modules
              2.2. External Libraries or Applications

        3. Parameters

              3.1. load (string)
              3.2. script_init (string)
              3.3. script_child_init (string)
              3.4. threads_mode (int)

        4. Functions

              4.1. app_python3s_exec(method [, param])

        5. RPC Commands

              5.1. app_python.reload
              5.2. app_python.api_list

        6. KEMI Usage

   List of Examples

   1.1. Set load parameter
   1.2. Set script_init parameter
   1.3. Set script_child_init parameter
   1.4. Set threads_mode parameter
   1.5. app_python3s_exec usage

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies

        2.1. Kamailio Modules
        2.2. External Libraries or Applications

   3. Parameters

        3.1. load (string)
        3.2. script_init (string)
        3.3. script_child_init (string)
        3.4. threads_mode (int)

   4. Functions

        4.1. app_python3s_exec(method [, param])

   5. RPC Commands

        5.1. app_python.reload
        5.2. app_python.api_list

   6. KEMI Usage

1. Overview

   This module is an alternative 'app_python3' module with static export
   of 'KSR' object and functions, without instantiating the SIP message
   object.

   This module cannot be loaded together with 'app_python3' as some global
   symbols conflict.

   This module allows executing Python3 scripts from the config file,
   exporting functions to access the SIP message from Python3.

   Note: if symbols exported to KEMI (module or function names) conflict
   with Python's reserved keywords, use the 'getattr()' function or the
   '__dict__' attribute for 'KSR' (e.g.,
   'KSR.__dict__["async"].task_route("myroute")').

2. Dependencies

   2.1. Kamailio Modules
   2.2. External Libraries or Applications

2.1. Kamailio Modules

   The following modules must be loaded before this module:
     * none.

2.2. External Libraries or Applications

   The following libraries or applications must be installed before
   running Kamailio with this module loaded:
     * python3 - Python 3 runtime.

   To compile this module the Python 3 development package is needed.
   Requirements:
     * python3-dev - Python 3 development package.
     * python3-config - (part of python3-dev) tool to output C includes
       and library paths.

3. Parameters

   3.1. load (string)
   3.2. script_init (string)
   3.3. script_child_init (string)
   3.4. threads_mode (int)

3.1. load (string)

   The path to the file with Python code to be executed from configuration
   file.

   Default value is “/usr/local/etc/kamailio/kamailio.py”.

   Example 1.1. Set load parameter
...
modparam("app_python3s", "load", "/usr/local/etc/kamailio/myscript.py")
...

3.2. script_init (string)

   The name of the Python function to be executed when the script is
   loaded or reloaded.

   Default value is “” (not set).

   Example 1.2. Set script_init parameter
...
modparam("app_python3s", "script_init", "ksr_script_init")
...
def ksr_script_init():
    KSR.info("init python script\n")
    return 1
...

3.3. script_child_init (string)

   The name of the Python function to be executed when Kamailio forks
   child processes at startup and when the script is reloaded.

   Default value is “” (not set).

   Example 1.3. Set script_child_init parameter
...
modparam("app_python3s", "script_child_init", "ksr_script_child_init")
...
def ksr_script_child_init():
    KSR.info("child init python script\n")
    return 1
...

3.4. threads_mode (int)

   Control how locking for Python interpreter threads in done. If set to
   1, use Py_BLOCK_THREADS/Py_UNBLOCK_THREADS (new mode added for v6.0.x).
   If set to 0, use PyGILState_Ensure()/PyGILState_Release() (the mode
   implemented initially).

   If set to 1, Python threading Thread objects created in the KEMI script
   will be scheduled. Otherwise, additional Python threads will not be
   scheduled (no release of GIL).

   Default value is “0”.

   Example 1.4. Set threads_mode parameter
...
modparam("app_python3s", "threads_mode", 1)
...

4. Functions

   4.1. app_python3s_exec(method [, param])

4.1.  app_python3s_exec(method [, param])

   Execute the Python function with the name given by the parameter
   'method'. Optionally can be provided a second string with the parameter
   to be passed to the Python function.

   Both parameters can contain pseudo-variables.

   Example 1.5. app_python3s_exec usage
...
app_python3s_exec("my_python_function");
app_python3s_exec("my_python_function", "my_params");
app_python3s_exec("my_python_function", "$rU");
...

5. RPC Commands

   5.1. app_python.reload
   5.2. app_python.api_list

5.1.  app_python.reload

   IMPORTANT: this is not thread-safe. In your Python script do not use C
   extensions with threads that call into apy_exec().

   Marks the need to reload the Python script. The actual reload is done
   in each worker when it next invokes a Python method. The module uses a
   worker process lock to prevent recursive reloads.

   This function only reloads (re-executes) the user script and creates a
   new script object. It does not reinitialize the interpreter (references
   in the old module remain if not redefined by the new version).

   Name: app_python.reload

   Parameters: none

   Example:
...
kamcmd app_python3s.reload
...

   Note that reload is done for the Python script provided as parameter to
   this Kamailio module. To reload the Python libraries imported in this
   script, leverage "script_init" and use something like:
...
import mod1
...
import modN
from importlib import reload

def ksr_script_init():
    reload(mod1)
    ...
    reload(modN)
    return kamailio()
...

   Where "modX" are the modules imported at the top.

5.2.  app_python.api_list

   List the functions available via Kemi framework.

   Name: app_python.api_list

   Parameters: none

   Example:
...
kamcmd app_python3s.api_list
...

6. KEMI Usage

   The module exports KEMI engine with id "python".

   Example:
...
loadmodule "app_python3s.so"
...
cfgengine "python"
...

   For more details about KEMI, see:
   https://www.kamailio.org/docs/tutorials/devel/kamailio-kemi-framework/
