Linux SysAdmin Tool

A modular command-line tool for Linux system administration. Manages users, services, networks, filesystems, monitoring, and security updates through an interactive menu.

Features

• User Management — Add, delete users with input validation (adduser/deluser)
• Service Management — Start, stop, restart, enable, disable systemd services
• Network Management — Ping hosts (validated), display network interfaces
• Filesystem Management — Format/mount disks with device validation, fstab backup, user confirmation
• System Monitoring — CPU, memory, and disk usage via psutil
• Security Management — Apply system security updates via apt
• Monolithic Mode — Standalone 4,000+ line single-file version (linux-sys-adm-tools.py) with 125 functions across 15 categories

Quick Start

# Install dependencies
pip install -r requirements.txt

# Run (requires sudo for most operations)
sudo python3 main.py

Docker

# Run interactively
docker-compose run app

# Run tests
docker-compose run test

# Run linter
docker-compose run lint

Usage

Interactive Mode

sudo python3 main.py

Presents a menu:

=== Linux SysAdmin Tool ===
1. User Management
2. Service Management
3. Network Management
4. System Monitoring
5. Filesystem Management
6. Security Management
7. Display README
0. Exit

Command-Line Options

python3 main.py --version    # Show version
python3 main.py --readme     # Display README

Monolithic Version

The standalone single-file version includes all 15 feature categories:

sudo python3 linux-sys-adm-tools.py

How To

Add a User

From the main menu, select 1. User Management, then 1. Add User.

Select an option: 1

--- User Management ---
1. Add User
2. Delete User
0. Back to Main Menu
Select an option: 1
Enter username to add: jsmith

The username must be alphanumeric (letters and numbers only). The tool runs sudo adduser jsmith and prompts for the new user's password and details.

Delete a User

Select 1. User Management, then 2. Delete User.

Enter username to delete: jsmith
Are you sure you want to delete user 'jsmith'? (y/n): y

This removes the user account and their home directory (deluser --remove-home).

Manage a Service

Select 2. Service Management and pick an action:

--- Service Management ---
1. Start Service
2. Stop Service
3. Restart Service
4. Enable Service
5. Disable Service
0. Back to Main Menu
Select an option: 1
Enter service name: nginx

Runs sudo systemctl <action> <service>. Service names are validated (no spaces or special characters).

Ping a Host

Select 3. Network Management, then 1. Ping Host.

--- Network Management ---
1. Ping Host
2. Display Network Interfaces
0. Back to Main Menu
Select an option: 1
Enter host to ping: 8.8.8.8

Sends 4 ICMP packets. Hostnames and IPs are validated before execution.

Display Network Interfaces

Select 3. Network Management, then 2. Display Network Interfaces.

Runs ip addr and shows all interfaces with their IP addresses, MAC addresses, and status. No root required.

Monitor System Resources

Select 4. System Monitoring from the main menu.

CPU Usage:
CPU Usage: 12.3%

Memory Usage:
Total: 15.64 GB
Used: 8.21 GB
Free: 4.38 GB
Memory Usage: 52.5%

CPU is sampled over a 1-second interval for accuracy.

Format and Mount a Disk

Select 5. Filesystem Management from the main menu.

Enter device path: /dev/sdb1
WARNING: This will format /dev/sdb1 and erase all data!
Are you sure you want to continue? (yes/no): yes

The tool will:

1. Validate the device path (must match /dev/...)
2. Ask for explicit confirmation (type yes)
3. Format with the configured filesystem (default: ext4)
4. Create the mount point directory
5. Mount the device
6. Back up /etc/fstab with a timestamp
7. Add a persistent UUID-based mount entry to /etc/fstab

Defaults are set in config.yaml (default_filesystem, default_mount_point).

Apply Security Updates

Select 6. Security Management from the main menu.

Runs sudo apt update followed by sudo apt dist-upgrade -y. This may take several minutes depending on available updates.

Project Structure

├── main.py                  # Entry point, interactive menu, CLI args
├── core.py                  # Logging, config, input validators
├── utils.py                 # Input sanitization utilities
├── config.yaml              # Default settings (filesystem, mount point, log level)
├── logging_setup.py         # JSON structured logging with rotation (optional)
├── user_management.py       # User add/delete with validation
├── service_management.py    # systemctl wrapper
├── network_management.py    # Ping, interface display
├── filesystem_management.py # Disk format/mount, fstab management
├── system_monitoring.py     # CPU/memory/disk monitoring
├── security_management.py   # apt update/upgrade
├── linux-sys-adm-tools.py   # Monolithic standalone version
├── tests/                   # pytest test suite (107 tests)
├── Dockerfile               # Container build
├── docker-compose.yml       # App, test, lint services
├── Makefile                 # Development task runner
├── setup.py                 # Package configuration
├── setup.cfg                # flake8, pytest, coverage, mypy config
├── requirements.txt         # Python dependencies
└── .pre-commit-config.yaml  # Pre-commit hooks

Configuration

Edit config.yaml:

default_filesystem: ext4
default_mount_point: /mnt/test
log_file: sysadmin_tool.log

Development

make test        # Run tests
make coverage    # Tests with coverage report
make lint        # flake8
make typecheck   # mypy
make check       # All of the above
make clean       # Remove build artifacts

Or without Make:

python3 -m pytest tests/ -v
flake8 . --max-line-length=120 --exclude=linux-sys-adm-tools.py,venv,__pycache__
mypy core.py utils.py main.py user_management.py service_management.py \
     network_management.py filesystem_management.py system_monitoring.py \
     security_management.py logging_setup.py

Adding a New Module

1. Create your_module.py with validation and error handling
2. Add it to the whitelist in main.py load_modules()
3. Add a menu entry in main.py
4. Create tests/test_your_module.py

Security Guidelines

• Never use shell=True with user input
• Validate all inputs via core.py validators before subprocess calls
• Use check=True on subprocess.run()
• Back up critical files (/etc/fstab) before modification
• Require user confirmation for destructive operations

Dependencies

Package	Purpose
pyyaml	YAML config parsing
psutil	System resource monitoring
python-crontab	Cron management (monolithic only)
pytest	Testing
flake8	Linting
mypy	Type checking
pytest-cov	Coverage reporting

Changelog

v1.0.0 (2026-02-17)

Full security hardening, test coverage expansion, and development tooling.

Security

• Eliminated all shell=True command injection vulnerabilities in monolithic file (13 instances)
• Added input validation functions: validate_username, validate_service_name, validate_host, validate_device_path, validate_package_name
• Applied validators to all critical functions in both modular and monolithic versions
• Added sanitize_input() and sanitize_numeric() helpers

Testing

• Expanded test suite from 9 to 107 tests
• Added test files for all modules: core, user, service, network, filesystem, monitoring, security, logging, main, utils
• Added conftest.py with shared fixtures
• 94-100% coverage on modular code

Architecture

• Switched module loader from blacklist to whitelist approach
• Removed unused config_manager.py (duplicate of core.load_config())
• Fixed display_readme import in main.py
• Fixed psutil.cpu_percent() to use interval=1 for accurate readings
• Added CLI argument parsing (--version, --readme)
• Added type hints and docstrings to all modules

Infrastructure

• Added Docker support (Dockerfile, docker-compose.yml with app/test/lint services)
• Added Makefile with test, lint, typecheck, coverage, clean targets
• Added setup.py and setup.cfg for packaging
• Added requirements.txt with pinned minimum versions
• Added .pre-commit-config.yaml (flake8, mypy, trailing whitespace, pyupgrade)
• Added .gitignore
• Added logging_setup.py with JSON structured logging, log rotation, and audit trail

Code Quality

• Zero flake8 errors across modular codebase
• Zero mypy errors
• Fixed grammatically incorrect log messages in service management
• Added constants for magic numbers (BYTES_TO_GB, DEFAULT_PING_COUNT)
• Automatic fstab backup with timestamps before filesystem modifications

v0.1.0 (Initial)

• Initial implementation with modular architecture
• Basic user, service, network, filesystem, monitoring, and security modules
• Monolithic single-file version with 125 functions
• Core logging and configuration infrastructure

License

MIT