Phase 1: Foundation Infrastructure for Script Modernization

[errnair]

Description

This PR establishes the foundation infrastructure for modernizing the sysadmin-shell-scripts repository. Phase 1 creates shared libraries, configuration management, comprehensive documentation, and testing infrastructure that will be used across all scripts in future phases.

Objective: Build a solid foundation for script modernization with reusable components, security best practices, and multi-OS support.

Changes

1. Shared Function Library (lib/common.sh)

• 548 lines of reusable bash functions
• 40+ functions covering:
  • Color output (5 functions): print_info, print_success, print_warning, print_error, print_header
  • OS detection (3 functions): detect_os, detect_os_version, get_package_manager
  • Input validation (4 functions): validate_domain, validate_ip, validate_port, validate_hostname
  • Backup utilities (2 functions): backup_file, backup_dir
  • Logging (3 functions): log_info, log_error, log_success
  • Service management (2 functions): start_and_enable, restart_service
  • Firewall management (1 function): open_firewall_port
  • Error handling (2 functions): error_exit, cleanup_on_exit
  • Dry-run support (2 functions): is_dry_run, dry_run_execute
  • Network utilities (3 functions): get_public_ip, get_private_ip, check_internet
  • File integrity (2 functions): verify_checksum, download_with_verify
  • User interaction (2 functions): confirm, read_password

2. Configuration Management (config/)

• Global defaults (defaults.conf): Backup settings, network timeouts, security defaults
• Template configurations for major scripts:
  • ansible.conf.example: Version, installation method, collections
  • flask.conf.example: Domain, SSL, Gunicorn settings
  • jenkins.conf.example: Java version, plugins, memory settings
  • backup.conf.example: S3/rsync, retention, encryption
• Configuration guide (config/README.md): 226 lines with examples and troubleshooting

3. Documentation

• Enhanced README.md (350 lines): Complete documentation with examples, compatibility matrix, troubleshooting
• CONTRIBUTING.md (403 lines): Development guidelines, coding standards, testing requirements, PR process
• LICENSE: MIT License for open source
• CHANGELOG.md: Version history tracking

4. Security & Version Control

• .gitignore (166 lines): Protects credentials, SSH keys, config files, backups
• Secure defaults in configuration
• Password handling guidelines

5. Testing Infrastructure

• tests/test_common_demo.sh: Demo test script validating library functions
• All core functions tested and passing
• Ready for BATS integration

6. Summary Documentation

• PHASE1_SUMMARY.md: Comprehensive implementation summary with metrics and next steps

Tests

Library Function Tests

✅ All tests passing - Validated via tests/test_common_demo.sh

Test Coverage:

• ✅ Color output functions (5/5)
• ✅ OS detection (works on macOS, Linux detection ready)
• ✅ Command existence checks
• ✅ Input validation:
  • ✅ Valid IP: 192.168.1.1 (accepted)
  • ✅ Invalid IP: 999.999.999.999 (rejected)
  • ✅ Valid port: 8080 (accepted)
  • ✅ Invalid port: 99999 (rejected)
  • ✅ Valid hostname: myserver (accepted)
  • ✅ Invalid hostname: invalid-hostname- (rejected)
  • ✅ Valid domain: example.com (accepted)
  • ✅ Invalid domain: notadomain (rejected)
• ✅ Version comparison
• ✅ Dry-run mode simulation

Test Execution:

bash tests/test_common_demo.sh
# All tests pass successfully

Manual Testing

• ✅ Library loads without errors
• ✅ Functions work as expected
• ✅ Configuration files parse correctly
• ✅ Documentation renders properly

Static Analysis

• ✅ Bash scripts use proper shebangs
• ✅ Files have correct permissions (executable where needed)
• ✅ No syntax errors in shell scripts

Metrics

Metric	Value
Files Created	13
Files Modified	1 (README.md)
Total Lines Added	~2,500
Functions in Library	40+
Configuration Templates	5
Documentation Pages	4

Impact

• No breaking changes - All existing scripts remain functional
• Backward compatible - New infrastructure is additive only
• Ready for Phase 2 - Foundation set for modernizing existing scripts

Next Steps

After this PR is merged, Phase 2 will:

1. Fix critical security issues (password handling in create_db.sh, sync_emails.sh)
2. Fix corrupted portcheck.py file
3. Modernize installation scripts with common library integration
4. Add multi-OS support across all scripts