---
title: Plugin System
description: Plugin system for extending functionality with dynamic component loading, security validation, custom UI components, and data sources.
---
## Table of Contents
- [Overview](#overview)
- [Plugin Architecture](#plugin-architecture)
- [Security Model](#security-model)
- [Plugin Development](#plugin-development)
- [Configuration](#configuration)
- [Examples](#examples)
- [Best Practices](#best-practices)
## Overview
The BoxMux plugin system enables:
- **Dynamic Component Loading**: Load custom components at runtime using `libloading`
- **Security Validation**: Permission-based access control with manifest validation
- **Fallback System**: Graceful fallback to mock implementations for development/testing
- **Manifest Parsing**: TOML-based plugin manifests with dependency management
- **Type Safety**: Type-safe plugin interfaces with Rust's type system
### Key Features
- **Permission-based Security**: Plugins declare required permissions (filesystem, network, process, environment)
- **Sandbox Execution**: Plugins run in controlled environments with resource limits
- **Dynamic Library Loading**: Real .so/.dll plugin files loaded at runtime
- **Manifest Validation**: Plugin manifests validated before loading
- **Component Registry**: Central registry managing loaded plugins with type-based lookup
- **Fallback Rendering**: Automatic fallback to mock implementations when plugins fail to load
## Plugin Architecture
### Plugin Lifecycle
1. **Manifest Discovery**: BoxMux scans for plugin manifest files (`.toml` format)
2. **Manifest Validation**: Validates plugin metadata, dependencies, and permissions
3. **Security Check**: Verifies requested permissions against security policy
4. **Dynamic Loading**: Attempts to load plugin shared library using `libloading`
5. **Interface Binding**: Binds plugin functions to BoxMux plugin interface
6. **Registration**: Registers plugin in component registry for use by boxes
7. **Fallback Handling**: Falls back to mock implementation if loading fails
### Component Types
The plugin system supports various component types:
- **Data Visualizers**: Custom chart types and visualization components
- **Data Sources**: Custom data fetching and processing components
- **UI Components**: Custom box types and interactive elements
- **Processors**: Data transformation and analysis components
- **Integrations**: External system integrations and API connectors
## Security Model
### Permission System
Plugins must declare required permissions in their manifest:
#### Available Permissions
- `filesystem_read`: Read access to file system
- `filesystem_write`: Write access to file system
- `network_access`: Network communication access
- `process_spawn`: Ability to spawn child processes
- `environment_access`: Access to environment variables
- `system_info`: Access to system information APIs
#### Permission Validation
```toml
# plugin-manifest.toml
[security]
permissions = [
"filesystem_read",
"network_access"
]
sandbox_enabled = true
resource_limits = { memory = "100MB", cpu_time = "5s" }
```
### Security Manager
The `PluginSecurityManager` validates permissions and enforces security policies:
- **Permission Checking**: Validates plugin permissions against declared requirements
- **Resource Limits**: Enforces memory, CPU, and time limits
- **Sandbox Isolation**: Isolates plugin execution from main application
- **Access Control**: Controls plugin access to system resources
## Plugin Development
### Plugin Interface
Plugins must implement the core plugin interface:
```rust
// Plugin trait (simplified example)
pub trait BoxMuxPlugin {
fn get_name(&self) -> &str;
fn get_version(&self) -> &str;
fn render(&self, config: &PluginConfig) -> Result<String, PluginError>;
fn update(&mut self, data: &[u8]) -> Result<(), PluginError>;
}
```
### Plugin Manifest
Each plugin requires a TOML manifest file:
```toml
# example-plugin.toml
[plugin]
name = "metrics_visualizer"
version = "1.0.0"
description = "Advanced metrics visualization plugin"
author = "Developer Name"
license = "MIT"
[binary]
path = "libmetrics_visualizer.so"
entry_point = "create_plugin"
[dependencies]
boxmux = ">=0.76.0"
serde = "1.0"
[security]
permissions = [
"filesystem_read",
"network_access"
]
sandbox_enabled = true
[config]
schema = "config-schema.json"
default_config = { refresh_rate = 1000, max_points = 100 }
```
### Plugin Implementation Example
```rust
// libmetrics_visualizer/src/lib.rs
use boxmux_plugin_api::*;
pub struct MetricsVisualizerPlugin {
name: String,
version: String,
}
impl BoxMuxPlugin for MetricsVisualizerPlugin {
fn get_name(&self) -> &str {
&self.name
}
fn get_version(&self) -> &str {
&self.version
}
fn render(&self, config: &PluginConfig) -> Result<String, PluginError> {
// Custom visualization logic
let data = self.fetch_metrics(config)?;
let visualization = self.create_heatmap(&data)?;
Ok(visualization)
}
fn update(&mut self, data: &[u8]) -> Result<(), PluginError> {
// Update plugin state with new data
Ok(())
}
}
// Plugin entry point
#[no_mangle]
pub extern "C" fn create_plugin() -> Box<dyn BoxMuxPlugin> {
Box::new(MetricsVisualizerPlugin {
name: "metrics_visualizer".to_string(),
version: "1.0.0".to_string(),
})
}
```
## Configuration
### Box Plugin Configuration
Use plugins in box configurations:
```yaml
# Basic plugin usage
- id: 'custom_viz'
title: 'Custom Visualization'
plugin_type: 'metrics_visualizer'
plugin_config:
data_source: '/var/log/metrics.json'
visualization_type: 'heatmap'
refresh_rate: 1000
security_permissions:
- 'filesystem_read'
# Advanced plugin configuration
- id: 'api_monitor'
title: 'API Status Monitor'
plugin_type: 'http_monitor'
plugin_config:
endpoints:
- name: 'Main API'
url: 'https://api.example.com/health'
timeout: 5000
expected_status: 200
- name: 'Database API'
url: 'https://db.example.com/status'
timeout: 3000
headers:
Authorization: 'Bearer ${API_TOKEN}'
display_format: 'status_grid'
alert_threshold: 500
security_permissions:
- 'network_access'
- 'environment_access'
```
### Plugin Registry Configuration
Configure plugin discovery and loading:
```yaml
app:
plugin_config:
plugin_directories:
- '/usr/local/lib/boxmux/plugins'
- '~/.boxmux/plugins'
- './plugins'
security_policy: 'strict' # strict, permissive, development
fallback_enabled: true
cache_enabled: true
```
## Examples
### Data Visualization Plugin
```yaml
# Custom metrics dashboard
- id: 'metrics_dashboard'
title: 'Advanced Metrics'
plugin_type: 'prometheus_visualizer'
plugin_config:
prometheus_url: 'http://localhost:9090'
metrics:
- name: 'cpu_usage'
query: 'rate(cpu_usage_total[5m])'
chart_type: 'line'
- name: 'memory_usage'
query: 'memory_usage_bytes / memory_total_bytes * 100'
chart_type: 'gauge'
refresh_interval: 5000
security_permissions:
- 'network_access'
```
### External Integration Plugin
```yaml
# Kubernetes cluster monitor
- id: 'k8s_monitor'
title: 'Kubernetes Status'
plugin_type: 'kubernetes_monitor'
plugin_config:
kubeconfig: '~/.kube/config'
namespace: 'default'
resources:
- 'pods'
- 'services'
- 'deployments'
display_format: 'table'
security_permissions:
- 'filesystem_read'
- 'network_access'
- 'process_spawn'
```
### Custom Data Processor Plugin
```yaml
# Log analysis plugin
- id: 'log_analyzer'
title: 'Log Analysis'
plugin_type: 'log_processor'
plugin_config:
log_files:
- '/var/log/nginx/access.log'
- '/var/log/nginx/error.log'
analysis_type: 'real_time'
filters:
- 'error_level >= warning'
- 'response_time > 1000'
aggregation_window: '5m'
security_permissions:
- 'filesystem_read'
```
### Development Plugin (Mock Fallback)
```yaml
# Development plugin with fallback
- id: 'dev_plugin'
title: 'Development Feature'
plugin_type: 'experimental_feature'
plugin_config:
feature_flag: 'enable_new_ui'
mock_data: true
# No security_permissions - will use mock implementation
```
## Best Practices
### Plugin Development
1. **Clear Interfaces**: Design clean, well-documented plugin interfaces
2. **Error Handling**: Implement comprehensive error handling and recovery
3. **Resource Management**: Properly manage memory and system resources
4. **Testing**: Include comprehensive tests for plugin functionality
5. **Documentation**: Provide clear documentation and examples
### Security Considerations
1. **Minimal Permissions**: Request only necessary permissions
2. **Input Validation**: Validate all input data and configuration
3. **Sandbox Isolation**: Use sandbox mode for untrusted plugins
4. **Regular Updates**: Keep plugins updated with security patches
5. **Code Review**: Review plugin code for security vulnerabilities
### Configuration Management
1. **Schema Validation**: Use JSON schemas for plugin configuration validation
2. **Default Values**: Provide sensible defaults for plugin configuration
3. **Environment Variables**: Support environment-based configuration
4. **Hot Reloading**: Design plugins to support configuration updates
5. **Fallback Strategies**: Implement graceful fallback for plugin failures
### Performance Optimization
1. **Lazy Loading**: Load plugins only when needed
2. **Caching**: Cache plugin results where appropriate
3. **Resource Limits**: Set appropriate resource limits for plugins
4. **Profiling**: Profile plugin performance and optimize bottlenecks
5. **Memory Management**: Monitor and optimize memory usage
### Development Workflow
1. **Mock Development**: Use mock implementations during development
2. **Incremental Testing**: Test plugins incrementally with real data
3. **Integration Testing**: Test plugin integration with BoxMux
4. **Performance Testing**: Verify plugin performance under load
5. **Security Testing**: Test plugin security and permission handling
### Plugin Distribution
1. **Package Management**: Use proper package management for plugin distribution
2. **Version Compatibility**: Maintain backward compatibility where possible
3. **Dependency Management**: Clearly document and manage dependencies
4. **Installation Scripts**: Provide easy installation and setup scripts
5. **Update Mechanisms**: Implement plugin update and migration mechanisms
---
For plugin configuration reference, see [Configuration Reference](configuration.md).
For development examples, see [User Guide](user-guide.md).
For security guidelines, see the Security section in the main documentation.