Plugin

Plugin feature for the log collector is to load a user python functions at runtime by the engine and execute it.

The design infrastructure allows user to extend or call their existing python scripts without needing to expose the implementation. This enriches the log collection and mechanize the work flow as per user driven as per their requirement,

Understanding Plugin

The plugin works like any stand-alone piece of python script or library function.

The main components in plugin infrastructure are:

• plugin directory
• plugin directive in YAML
• plugin parser in the collector engine

Plugin Directory

Python module script are added or copied to plugins directory and the log engine loads these plugins during runtime and on demand from the YAML else they are not invoked automatically.

Example:

plugins/
├── foo_func.py
├── ssh_execution.py
└── telnet_execution.py

Plugin Template Example

plugins/foo_func.py

# Sample for documentation plugin

def print_vars(var):
    print(var)

def return_vars():
    return 1

You can add your own plugin modules to extend further.

Test your plugin:

python3 plugins/foo_func.py

YAML Syntax

Plugin function without return statement.

    - plugin:
        - plugin_name: plugin.foo_func.print_vars
        - plugin_args:
            - "Hello plugin"

Plugin function with return statement.

    - plugin:
        - plugin_name: return_value = plugin.foo_func.return_vars
        - plugin_args:

when the return directive is used by implying "=" , the return_value can be accessed within the same block by another following plugins by using the variable name directly.

Example:

    - plugin:
        - plugin_name: plugin.foo_func.print_vars
        - plugin_args:
            - return_value

To accept multiple return values by using coma "," separated statement

     - plugin_name:  return_value1,return_value2 = plugin.foo_func.print_vars

Plugin execution output for sample

        [PLUGIN-START]
        Call func: plugin.foo_func.print_vars("Hello plugin")
        Hello plugin
        return: None
        [PLUGIN-END]

        [PLUGIN-START]
        Call func: plugin.foo_func.return_vars()
        return: 1
        [PLUGIN-END]

Plugin FILES Direcive

Rules:

If in the YAML with Plugin module called and corresponding file order

plugin response if there is any will be written to named file, if

    FILES:
        -'name_file.txt'

Else, plugin response will be skipped and not written to any file.

    FILES:
        - None