🦖 Rex

A Swiss Army Knife CLI for DevOps Engineers

Encrypt secrets, lint configs, generate passwords, inspect certificates — all from your terminal.

Installation · Quick Start · Commands · Contributing

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⚡ Installation

# From PyPI
pip install rex-cli

# With JMESPath query support
pip install rex-cli[query]

# From source
git clone https://github.com/DavidHayter/rex-cli.git
cd rex-cli
pip install -e ".[dev]"

Verify installation:

rex version

🚀 Quick Start

# Encrypt a secret
rex encrypt enc "my-database-password" -p

# Beautify a JSON file
rex json beautify --file config.json --output pretty.json

# Lint your Kubernetes YAML
rex yaml lint deployment.yaml

# Generate a secure password
rex password generate --length 32

# Explain a cron expression
rex cron explain "*/5 9-17 * * 1-5"

# Hash a file
rex hash generate --file backup.tar.gz --all

# Check SSL certificate expiry
rex cert expiry example.com

# Scan open ports
rex net port 192.168.1.1 22,80,443,8080

📖 Commands

🔐 rex encrypt — Encryption & Decryption

Encrypt and decrypt data using industry-standard algorithms with password-based key derivation (PBKDF2, 480k iterations).

# Encrypt with AES-256-GCM (default)
rex encrypt enc "sensitive data" -p
> Enter password: ****

# Encrypt with ChaCha20-Poly1305
rex encrypt enc "sensitive data" -p --algo chacha20-poly1305

# Encrypt a file
rex encrypt enc -p --file secrets.env --output secrets.enc

# Decrypt
rex encrypt dec "eyJhbGci..." -p

# List supported algorithms
rex encrypt algorithms

Algorithm	Description
aes-256-gcm	Default. NIST standard, authenticated encryption
chacha20-poly1305	Fast on devices without AES hardware support
fernet	High-level symmetric encryption (AES-128-CBC + HMAC)

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📋 rex json — JSON Operations

# Beautify
rex json beautify '{"name":"rex","version":1}' --indent 4

# Beautify from file and save
rex json beautify --file raw.json --output pretty.json

# Minify
rex json minify --file config.json

# Validate
rex json validate --file package.json

# Query with JMESPath (requires: pip install rex-cli[query])
cat data.json | rex json query "users[?age > `30`].name"

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📄 rex yaml — YAML Operations

# Lint a YAML file
rex yaml lint deployment.yaml

# Strict mode (warns on tabs, trailing whitespace)
rex yaml lint values.yaml --strict

# Convert YAML to JSON
rex yaml to-json --file values.yaml --output values.json

# Convert JSON to YAML
rex yaml to-yaml --file config.json --output config.yaml

# Validate YAML syntax
rex yaml validate "key: value"

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🔑 rex password — Password Generation

# Generate a 24-char password (default)
rex password generate

# Custom length, multiple passwords
rex password generate --length 48 --count 5

# No symbols
rex password generate --length 16 --no-symbols

# Exclude ambiguous characters
rex password generate --exclude "0OlI1"

# Generate a passphrase
rex password passphrase --words 6 --separator "-"

# Capitalized passphrase
rex password passphrase --words 5 --capitalize --separator "."

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⏰ rex cron — Cron Expressions

# Explain a cron expression
rex cron explain "30 2 * * 0"

# Show all presets
rex cron presets

# Use a preset
rex cron generate daily
rex cron generate backup-nightly
rex cron generate business-hours

# Build custom expression
rex cron generate --minute "*/15" --hour "9-17" --weekday "1-5"

DevOps-focused presets: health-check, backup-nightly, cleanup-weekly, log-rotation, cert-renewal, and more.

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🔒 rex hash — Hash Generation

# SHA-256 hash (default)
rex hash generate "hello world"

# All algorithms at once
rex hash generate "hello world" --all

# Hash a file
rex hash generate --file backup.tar.gz --algo sha512

# HMAC
rex hash hmac "message" --key "my-secret" --algo sha256

# Verify a hash
rex hash verify "hello" --expected "2cf24dba..."

Algorithm	Output Length
md5	128-bit
sha1	160-bit
sha256	256-bit
sha512	512-bit
blake2b	512-bit
blake2s	256-bit

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📦 rex base64 — Base64 Operations

# Encode
rex base64 encode "hello world"

# Decode
rex base64 decode "aGVsbG8gd29ybGQ="

# URL-safe encoding
rex base64 encode "https://example.com?q=test" --url-safe

# File operations
rex base64 encode --file image.png --output image.b64
rex base64 decode --file image.b64 --output restored.png

# Pipe support
echo "secret" | rex base64 encode

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🎫 rex jwt — JWT Token Inspection

# Decode a JWT
rex jwt decode "eyJhbGciOiJIUzI1NiIs..."

# Pipe from clipboard
pbpaste | rex jwt decode

# Shows:
# - Header (algorithm, type)
# - Payload (all claims)
# - Expiry status (VALID / EXPIRED)
# - Issued at, subject, issuer, audience

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🆔 rex uuid — UUID Generation

# Generate UUID v4 (random)
rex uuid generate

# Multiple UUIDs
rex uuid generate --count 10

# UUID v1 (timestamp-based)
rex uuid generate --version 1

# UUID v5 (namespace + name)
rex uuid generate --version 5 --name "example.com"

# Uppercase
rex uuid generate --upper

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📜 rex cert — SSL/TLS Certificate Inspection

# Full certificate details
rex cert inspect google.com

# Check expiry (great for monitoring scripts)
rex cert expiry google.com
rex cert expiry --warn 60 production-api.company.com

# Custom port
rex cert inspect mail.example.com --port 465

Exit codes for cert expiry (perfect for monitoring):

• 0 — Certificate is valid
• 1 — Certificate expiring soon (within --warn days)
• 2 — Certificate expired or connection failed

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🌐 rex net — Network Utilities

# DNS lookup
rex net dns example.com
rex net dns example.com --type MX
rex net dns example.com --type TXT

# Port scanning
rex net port 192.168.1.1 22,80,443
rex net port server.com 8000-8010

# Ping
rex net ping 8.8.8.8
rex net ping google.com --count 10

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🔧 Pipe Support

Rex supports Unix pipes across all commands:

# Chain commands
echo '{"key":"value"}' | rex json beautify
cat config.yaml | rex yaml to-json
echo "secret" | rex base64 encode
echo "secret" | rex hash generate --all
pbpaste | rex jwt decode

🧪 Development

# Clone and install
git clone https://github.com/DavidHayter/rex-cli.git
cd rex-cli
pip install -e ".[dev]"

# Run tests
pytest

# Run with coverage
pytest --cov=rex --cov-report=html

# Lint
ruff check rex/
ruff format rex/

# Type check
mypy rex/

📦 Project Structure

rex-cli/
├── rex/
│   ├── __init__.py          # Version & metadata
│   ├── cli.py               # Main CLI entry point
│   └── commands/
│       ├── encrypt_cmd.py   # Encryption & decryption
│       ├── json_cmd.py      # JSON operations
│       ├── yaml_cmd.py      # YAML operations
│       ├── password_cmd.py  # Password generation
│       ├── cron_cmd.py      # Cron expressions
│       ├── hash_cmd.py      # Hash generation
│       ├── base64_cmd.py    # Base64 encode/decode
│       ├── jwt_cmd.py       # JWT inspection
│       ├── uuid_cmd.py      # UUID generation
│       ├── cert_cmd.py      # SSL/TLS inspection
│       └── network_cmd.py   # Network utilities
├── tests/
│   └── test_cli.py          # Test suite
├── pyproject.toml            # Package configuration
├── LICENSE                   # MIT License
├── CHANGELOG.md              # Version history
└── README.md                 # This file

🗺️ Roadmap

• rex k8s — Kubernetes context switcher & resource inspector
• rex docker — Docker image size analyzer & cleanup
• rex env — .env file encryption & diff
• rex tf — Terraform state inspector
• rex log — Log parser with pattern matching
• Plugin system for community extensions

📝 License

MIT — see LICENSE for details.

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