Configuration and Environment Variables

Relevant source files

The following files were used as context for generating this wiki page:

• README.md
• SECURITY.md
• CONTRIBUTING.md
• INSTALLATION.md
• CLEANUP_REPORT.md
• CHANGELOG.md

The Smart Absen Face Recognition system utilizes a combination of a central config.py file and environment variables (.env file) to manage application settings. This approach separates configuration from the codebase, enhancing security and portability. Sensitive information, such as database credentials and secret keys, are stored in a local .env file, which is excluded from version control, while non-sensitive, default configurations may reside in config.py.

This system was introduced in version 2.0.0 as a major security and architectural update, moving away from hardcoding all values in config.py. The application now uses the python-dotenv library to load these variables at runtime.

Sources: README.md:16-17, SECURITY.md:4-6, CHANGELOG.md:14-15, CONTRIBUTING.md:37-38

Configuration Setup

Setting up the local configuration is a required step for development. The process involves creating a .env file from the provided template and populating it with the correct values for the local environment.

The following diagram illustrates the setup workflow for a new developer.

Step-by-Step Guide

1. Copy the Template: In the project's root directory, copy the .env.example file to a new file named .env.

   cp .env.example .env
   

2. Edit the .env File: Open the newly created .env file and modify the variables with your local setup details, such as database credentials and a unique secret key.

   nano .env # Or use your preferred editor
   

3. Generate a Secret Key: For production or secure environments, generate a strong, random secret key.

   python3 -c "import secrets; print(secrets.token_hex(32))"
   

   Copy the output and paste it as the value for SECRET_KEY in your .env file.

Sources: README.md:23-24, SECURITY.md:52-61, INSTALLATION.md:147-151

Configuration Loading Flow

The application loads configuration from multiple sources in a specific order. The config.py file is responsible for reading the .env file and making the variables available to the main Flask application (app.py).

This diagram shows how configuration values flow from the .env file to the application at runtime.

Environment Variables

All environment-specific settings and secrets are managed through the .env file. The table below details the variables defined in .env.example.

Variable	Description	Example	Source(s)
DB_HOST	The hostname or IP address of the MySQL database server.	localhost	README.md:83
DB_USER	The username for the MySQL database.	root	README.md:84
DB_PASSWORD	The password for the specified database user.	yourpassword	README.md:85
DB_NAME	The name of the database to use for the application.	smart_absen	README.md:86
SECRET_KEY	A secret key used by Flask for session management and security.	your-secret-key	README.md:89
FLASK_ENV	The Flask environment mode.	production	README.md:90
PORT	The port on which the Flask application will run.	5001	README.md:91
DEBUG	A boolean to enable or disable Flask's debug mode.	True	CONTRIBUTING.md:44
FACE_CONFIDENCE	The confidence threshold for face recognition.	0.6	README.md:94
MAX_FACES	The maximum number of faces to detect in a single frame.	1	README.md:95

Sources: README.md:82-95, CONTRIBUTING.md:41-44, SECURITY.md:59-62

Example .env File

This is an example of what a developer's local .env file might look like. This file must not be committed to version control.

# Database
DB_HOST=localhost
DB_USER=root
DB_PASSWORD=yourpassword
DB_NAME=smart_absen

# App
SECRET_KEY=your-secret-key
FLASK_ENV=production
PORT=5001

# ML Config
FACE_CONFIDENCE=0.6
MAX_FACES=1

Sources: README.md:82-95

Hardcoded Configuration

Before the v2.0.0 refactor, all configuration was hardcoded in config.py. While most sensitive data has been moved to .env, some non-sensitive or default values may still reside in config.py. The INSTALLATION.md file provides insight into the previous structure of this file.

The following variables were previously defined directly in config.py:

Variable	Description	Default Value
DB_HOST	Host for the MySQL database.	localhost
DB_USER	Username for the database.	root
DB_PASSWORD	Password for the database.	your_password
DB_NAME	Name of the database.	absensi_karyawan_db
SECRET_KEY	Flask secret key.	your-secret-key-here
DEBUG	Flask debug mode.	True
HOST	Host for the application to listen on.	0.0.0.0
PORT	Port for the application.	5001

Sources: INSTALLATION.md:135-145

Security and Best Practices

The primary motivation for using environment variables is to enhance security by decoupling secrets from the source code.

• Exclusion from Git: The .env file is listed in .gitignore to prevent it from being accidentally committed to the repository. This ensures that sensitive credentials are not exposed.
• Environment Portability: Each environment (development, staging, production) can have its own .env file with different settings (e.g., different database hosts) without requiring any code changes.
• Centralized Management: config.py acts as a single source of truth for configuration within the application, loading values from the environment and providing them to other modules like app.py.

Sources: SECURITY.md:4-12, CLEANUP_REPORT.md:40, 56, CONTRIBUTING.md:40