Plugin System

def load_plugins(plugin_mapping, event_hooks=None, include_builtins=True):
    """
    Load and initialize plugins for AWS CLI.
    
    Parameters:
        plugin_mapping: dict, mapping of plugin names to module paths
        event_hooks: botocore event emitter, optional event system
        include_builtins: bool, whether to load built-in plugins (default True)
    """

BUILTIN_PLUGINS: dict  # {'__builtin__': 'awscli.handlers'}

from awscli.plugin import load_plugins

# Load custom plugins
custom_plugins = {
    'my-plugin': 'mypackage.aws_plugin',
    'dev-tools': 'devtools.aws_extensions'
}

load_plugins(custom_plugins, include_builtins=True)

# mypackage/aws_plugin.py
def awscli_initialize(cli):
    """
    Plugin initialization function called by AWS CLI.
    
    Parameters:
        cli: AWS CLI instance for registration
    """
    # Register event handlers
    cli.register('before-call', modify_request)
    cli.register('after-call', process_response)
    
    # Register custom commands
    cli.register('building-command-table.main', add_commands)

def modify_request(event_name=None, **kwargs):
    """Handle before-call events."""
    print(f"Intercepting request: {event_name}")

def process_response(parsed, **kwargs):
    """Handle after-call events."""
    print(f"Processing response: {parsed}")

def add_commands(command_table, session, **kwargs):
    """Add custom commands to command table."""
    from mypackage.commands import CustomCommand
    command_table['custom'] = CustomCommand(session)

def register_handlers(cli):
    """Register various event handlers."""
    
    # Command table modification
    cli.register('building-command-table.main', add_main_commands)
    cli.register('building-command-table.s3', add_s3_commands)
    
    # Argument table modification
    cli.register('building-argument-table.s3.ls', add_s3_ls_args)
    
    # Request/response processing
    cli.register('before-call', modify_all_requests)
    cli.register('before-call.s3.ListObjects', modify_s3_list_request)
    cli.register('after-call', process_all_responses)
    
    # Output processing
    cli.register('doc-output', modify_documentation)

def add_s3_commands(command_table, session, **kwargs):
    """Add custom S3 commands."""
    from mypackage.s3_commands import S3SyncAdvanced
    command_table['sync-advanced'] = S3SyncAdvanced(session)

def add_s3_ls_args(argument_table, **kwargs):
    """Add arguments to s3 ls command."""
    from awscli.arguments import CustomArgument
    
    argument_table['include-metadata'] = CustomArgument(
        'include-metadata',
        help_text='Include object metadata in output',
        action='store_true'
    )

def modify_requests(event_name, endpoint, request_dict, **kwargs):
    """Modify AWS service requests."""
    
    # Add custom headers
    if 'headers' not in request_dict:
        request_dict['headers'] = {}
    request_dict['headers']['X-Custom-Plugin'] = 'MyPlugin-1.0'
    
    # Modify parameters
    if 'params' in request_dict:
        # Add default parameters
        request_dict['params'].setdefault('MaxItems', 100)

def process_responses(parsed, **kwargs):
    """Process AWS service responses."""
    
    # Add custom fields
    if isinstance(parsed, dict):
        parsed['_plugin_processed'] = True
        parsed['_processing_time'] = time.time()
    
    # Transform data
    if 'Instances' in parsed:
        for instance in parsed['Instances']:
            # Add computed fields
            instance['_display_name'] = f"{instance.get('InstanceId', 'unknown')}"

# ~/.aws/config
[plugins]
my-plugin = mypackage.aws_plugin
dev-tools = devtools.aws_extensions

import os
from awscli.plugin import load_plugins

# Load plugins from environment
plugin_paths = os.environ.get('AWS_CLI_PLUGINS', '').split(',')
plugin_mapping = {}

for plugin_path in plugin_paths:
    if plugin_path.strip():
        name = plugin_path.split('.')[-1]
        plugin_mapping[name] = plugin_path.strip()

load_plugins(plugin_mapping)

def conditional_load(cli):
    """Load plugins based on conditions."""
    
    # Only load in development
    if os.environ.get('AWS_CLI_ENV') == 'development':
        cli.register('building-command-table.main', add_dev_commands)
    
    # Load based on AWS profile
    current_profile = cli.session.get_config_variable('profile')
    if current_profile == 'production':
        cli.register('before-call', add_production_safeguards)

mypackage/
├── __init__.py
├── aws_plugin.py          # Main plugin module
├── commands/
│   ├── __init__.py
│   └── custom_commands.py # Custom command implementations
├── handlers/
│   ├── __init__.py
│   └── event_handlers.py  # Event handler implementations
└── setup.py               # Package configuration

# setup.py
from setuptools import setup, find_packages

setup(
    name='aws-cli-my-plugin',
    version='1.0.0',
    packages=find_packages(),
    install_requires=[
        'awscli>=1.40.0',
        'botocore>=1.30.0'
    ],
    entry_points={
        'console_scripts': [
            'aws-my-plugin=mypackage.cli:main'
        ]
    }
)

import unittest
from awscli.testutils import BaseCLIDriverTest

class TestMyPlugin(BaseCLIDriverTest):
    def setUp(self):
        super().setUp()
        # Load plugin for testing
        from mypackage.aws_plugin import awscli_initialize
        awscli_initialize(self.driver)
    
    def test_custom_command(self):
        """Test custom command functionality."""
        result = self.run_cmd(['custom', '--help'])
        self.assertEqual(result.rc, 0)
        self.assertIn('Custom command', result.stdout)
    
    def test_event_handler(self):
        """Test event handler integration."""
        result = self.run_cmd(['s3', 'ls'])
        # Verify plugin modifications
        self.assertIn('plugin_processed', result.stdout)