Configuration Overview

RMCP’s configuration system provides flexible, hierarchical configuration loading from multiple sources with automatic validation and type conversion.

Configuration Hierarchy

Configuration values are resolved in the following priority order:

Command-line arguments (highest priority)
Environment variables (RMCP_* prefix)
User configuration file (~/.rmcp/config.json)
System configuration file (/etc/rmcp/config.json)
Built-in defaults (lowest priority)

This hierarchy allows for flexible deployment scenarios where:

Defaults provide sensible starting values
System-wide configuration sets organizational policies
User configuration customizes personal preferences
Environment variables override settings for specific deployments
Command-line arguments provide immediate overrides for testing

Configuration Sources

Built-in Defaults

RMCP includes sensible defaults for all configuration options:

HTTP server binds to localhost:8000 for security
R timeout set to 120 seconds to prevent runaway processes
VFS read-only mode enabled for security
INFO-level logging for operational visibility

System Configuration

System administrators can set organization-wide defaults in /etc/rmcp/config.json:

{
  "security": {
    "vfs_read_only": true,
    "vfs_allowed_paths": ["/data/company"]
  },
  "r": {
    "max_sessions": 50,
    "timeout": 120
  },
  "logging": {
    "level": "INFO"
  }
}

User Configuration

Individual users can customize settings in ~/.rmcp/config.json:

{
  "http": {
    "port": 8080
  },
  "logging": {
    "level": "DEBUG"
  },
  "debug": true
}

Environment Variables

All configuration options support environment variable overrides with RMCP_* prefix:

export RMCP_HTTP_HOST=0.0.0.0
export RMCP_HTTP_PORT=9000
export RMCP_LOG_LEVEL=DEBUG

Command-Line Arguments

Command-line arguments provide the highest priority overrides:

rmcp --config custom.json --debug serve-http --port 9000

Configuration Categories

HTTP Transport

Controls HTTP server behavior:

Server binding address and port
SSL/TLS configuration
CORS origins for web clients
Security considerations

R Process Management

Manages R process execution:

Script execution timeouts
Session lifecycle and limits
Resource management
Custom R binary configuration

Security Controls

Virtual File System (VFS) security:

File access restrictions
Read-only mode enforcement
File size and type limits
Allowed filesystem paths

Performance Tuning

Resource and performance management:

Thread pool configuration
Timeout settings
Process cleanup controls
Concurrency limits

Logging Configuration

Log output control:

Log levels and formatting
Output destinations
Debug mode settings

Configuration Validation

Automatic Validation

RMCP automatically validates all configuration:

Type checking: Ensures values match expected types
Range validation: Ports, timeouts, and sizes within valid ranges
File validation: SSL certificates and paths exist if specified
Dependency validation: Related settings are consistent

Schema Validation

Configuration files are validated against a JSON schema:

Required fields must be present
Additional properties are allowed for extensibility
Nested structure must match expected format
Value constraints are enforced

Error Reporting

Configuration errors provide detailed information:

Source of the error (file, environment variable, CLI)
Specific validation failure
Suggested fixes
Example valid configurations

Common Patterns

Development Setup

# Quick development setup
export RMCP_DEBUG=true
export RMCP_LOG_LEVEL=DEBUG
export RMCP_VFS_READ_ONLY=false
rmcp start

Production Deployment

# Production with system config
sudo tee /etc/rmcp/config.json << EOF
{
  "http": {"host": "0.0.0.0", "port": 8000},
  "security": {"vfs_read_only": true},
  "r": {"max_sessions": 100},
  "logging": {"level": "INFO"}
}
EOF

rmcp serve-http

Docker Deployment

# Environment-based Docker config
docker run -e RMCP_HTTP_HOST=0.0.0.0 \\
           -e RMCP_R_MAX_SESSIONS=20 \\
           -p 8000:8000 rmcp:latest

Configuration Best Practices

Security

Keep VFS in read-only mode for production
Restrict allowed paths to necessary directories
Use SSL/TLS for external access
Set appropriate file size limits

Performance

Tune session limits based on available memory
Adjust timeouts for your workload
Configure thread pools for your CPU count
Monitor resource usage and adjust accordingly

Maintenance

Use configuration files for persistent settings
Use environment variables for deployment-specific overrides
Document configuration choices in deployment scripts
Validate configuration in CI/CD pipelines

Monitoring

Enable appropriate logging levels
Use debug mode for troubleshooting
Monitor configuration loading in application logs
Set up alerts for configuration validation failures