# &adminguide;

## 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")').

## Dependencies

### &kamailio; Modules

The following modules must be loaded before this module:

- none.

### 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.

## Parameters

### `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.

#### Set `load` parameter

    ...
    modparam("app_python3s", "load", "/usr/local/etc/kamailio/myscript.py")
    ...

### `script_init` (string)

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

Default value is (not set).

#### Set `script_init` parameter

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

### `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).

#### 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
    ...

### `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.

#### Set `threads_mode` parameter

    ...
    modparam("app_python3s", "threads_mode", 1)
    ...

## Functions

### `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.

#### `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");
    ...

## RPC Commands

### `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:

    ...
    &kamctl; rpc 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.

### `app_python.api_list`

List the functions available via Kemi framework.

Name: app_python.api_list

Parameters: none

Example:

    ...
    &kamctl; rpc app_python3s.api_list
    ...

## 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/