WordPress Migration Skill

This skill provides expertise for working with the wp-migrate.sh WordPress migration tool.

Project Overview

wp-migrate.sh is a comprehensive WordPress migration tool that operates in two modes:

1. Push Mode: Migrates WordPress sites between servers via SSH (source → destination)
2. Archive Mode: Imports WordPress backup archives (Duplicator, Jetpack Backup, Solid Backups) on destination server

Current Version: Check the latest release

bash
1git describe --tags --abbrev=0  # Get current version from git

Latest Release: See GitHub Releases

Repository: BWBama85/wp-migrate.sh

Main Branch: main

Core Capabilities

Migration Modes

Push Mode

• Transfers wp-content and database from source to destination via SSH
• Enables maintenance mode on both servers during migration
• Creates timestamped backups before overwriting
• Performs URL search-replace to align destination domain
• Excludes object-cache.php to preserve destination caching infrastructure
• Supports StellarSites managed hosting compatibility (--stellarsites flag)

Archive Mode

• Auto-detects archive format (Duplicator, Jetpack Backup, Solid Backups)
• Extracts archives to temporary directory
• Validates disk space (requires 3x archive size)
• Creates backups of destination database and wp-content before import
• Automatically aligns table prefixes if different from wp-config.php
• Performs URL search-replace to align with destination URLs
• Provides rollback instructions with exact commands

Key Features

• Migration preview with confirmation: Pre-migration summary with detailed stats and confirmation prompt (v2.6.0)
• Rollback command: Automatic restoration from backups with --rollback flag (v2.6.0)
• Progress indicators: Real-time progress bars for long-running operations when pv is installed (v2.6.0)
• Dry-run mode: Preview all operations without making changes (--dry-run)
• Verbose logging: Show detailed diagnostic information (--verbose)
• Trace mode: Show every command before execution (--trace)
• Plugin preservation: Preserve destination plugins/themes not in source (--preserve-dest-plugins)
• StellarSites mode: Managed hosting compatibility with mu-plugins exclusion (--stellarsites)
• Skip search-replace: Fast migrations that only update home/siteurl options (--no-search-replace)
• Automation support: Skip confirmation prompts with --yes flag for CI/CD (v2.6.0)
• Quiet mode: Suppress progress indicators for non-interactive scripts with --quiet (v2.6.0)

Common Tasks

Running Migrations

Push Mode:

bash
1./wp-migrate.sh --dest-host user@dest.example.com --dest-root /var/www/site

Archive Mode:

bash
1./wp-migrate.sh --archive /path/to/backup.zip
2./wp-migrate.sh --archive /path/to/backup.tar.gz --archive-type jetpack

Dry Run:

bash
1./wp-migrate.sh --dest-host user@dest --dest-root /var/www/site --dry-run --verbose

Rollback (v2.6.0):

bash
1./wp-migrate.sh --rollback  # Auto-detects latest backups
2./wp-migrate.sh --rollback --rollback-backup /path/to/specific/backup  # Specific backup
3./wp-migrate.sh --rollback --yes  # Skip confirmation for automation

Automation-Friendly (v2.6.0):

bash
1./wp-migrate.sh --archive /path/to/backup.zip --yes --quiet  # CI/CD: skip prompts, no progress bars

Testing

Run all tests:

bash
1make test

Run specific test:

bash
1./test-wp-migrate.sh

ShellCheck validation:

bash
1shellcheck wp-migrate.sh

Development Workflow

Code Structure (v2+)

The project uses a modular source structure:

src/
├── header.sh           # Shebang, defaults, variable declarations
├── lib/
│   ├── core.sh         # Core utilities (log, err, validate_url)
│   ├── functions.sh    # All other functions
│   └── adapters/       # Archive format adapters
│       ├── README.md
│       ├── duplicator.sh
│       ├── jetpack.sh
│       └── solidbackups.sh
└── main.sh             # Argument parsing and main execution

IMPORTANT: Modifications should be made in src/ files, NOT in wp-migrate.sh directly.

Build Process

After modifying source files:

bash
1make build

This will:

1. Run shellcheck on concatenated source
2. Concatenate src/ files into dist/wp-migrate.sh
3. Copy to ./wp-migrate.sh (repo root)
4. Generate SHA256 checksum

Pre-commit Hook

A pre-commit hook prevents committing source changes without rebuilding:

bash
1ln -s ../../.githooks/pre-commit .git/hooks/pre-commit

Git Workflow

1. Branching: Create from main using descriptive names:

   • feature/<slug> for enhancements
   • fix/<slug> for bug fixes
   • docs/<slug> for documentation
   • chore/<slug> for maintenance

2. Commits: Use .gitmessage template format:

   type: short imperative summary
   
   Longer explanation if needed
   

   Types: feat, fix, docs, chore, refactor, test

3. Changelog: Update CHANGELOG.md under [Unreleased] section with every feature or fix

4. Pull Requests:

   • Use .github/pull_request_template.md checklist
   • Include comprehensive summary based on ALL commits (not just latest)
   • Include test plan with verification steps
   • Reference related issues

5. Merging: Keep main release-ready with git merge --no-ff or squash after review

6. Releases: Tag with semantic versioning (e.g., git tag v2.7.0)

Creating Pull Requests

When creating PRs, ensure:

• Review ALL commits in the branch (use git log main..HEAD and git diff main...HEAD)
• Summary covers complete scope of changes
• Test plan verifies all functionality
• CHANGELOG.md is updated
• ShellCheck passes
• Tests pass (make test)

Common Files to Check

• wp-migrate.sh - Main script (built artifact, don't edit directly)
• src/ - Modular source files (edit these)
• src/lib/adapters/ - Archive format adapters
• CHANGELOG.md - Version history
• README.md - User documentation
• Makefile - Build and test targets
• test-wp-migrate.sh - Test script

Troubleshooting Guide

Common Issues

Permission Errors on Managed Hosts (StellarSites)

• Symptom: "Permission denied" when syncing wp-content
• Solution: Use --stellarsites flag to exclude protected mu-plugins
• Details: Managed hosts protect certain mu-plugins directories (e.g., stellarsites-cloud)

Database Import Fails

• Check table prefix alignment (script auto-detects and updates wp-config.php)
• Verify sufficient disk space (3x archive size for archive mode)
• Check MySQL max_allowed_packet size for large imports

URL Search-Replace Issues

• Use --verbose to see detected URLs
• Override with --dest-home-url or --dest-site-url if detection fails
• Use --no-search-replace for faster migrations that only need home/siteurl updated

Archive Detection Fails

• Use explicit --archive-type to specify format (duplicator, jetpack, solidbackups)
• Verify archive structure matches adapter expectations (see src/lib/adapters/)
• Check detailed validation errors with --verbose (v2.6.0+)

Non-Interactive Context Failures (v2.6.0)

• Symptom: Script exits with "This script requires a TTY for confirmation prompts"
• Solution: Add --yes flag when running in CI/CD, cron, or pipeline contexts
• Details: Migration preview and rollback require confirmation by default; use --yes to bypass

Rollback Issues (v2.6.0)

• Auto-detection looks for latest timestamped backups in db-backups/ and wp-content.backup-*
• If backups aren't found, use --rollback-backup /path/to/backup to specify explicitly
• Rollback only works for archive mode migrations (restores from local backups)

SSH Connection Issues

• Add custom SSH options with --ssh-opt (can be repeated)
• Examples: --ssh-opt 'Port=2222' or --ssh-opt 'ProxyJump=bastion'

ShellCheck Errors

• Install ShellCheck: brew install shellcheck (macOS) or see https://www.shellcheck.net/
• Run: shellcheck wp-migrate.sh
• All code must be ShellCheck-clean before merging

Debugging Commands

Show verbose migration preview:

bash
1./wp-migrate.sh --dest-host user@dest --dest-root /var/www/site --dry-run --verbose

Show every command (trace mode):

bash
1./wp-migrate.sh --dest-host user@dest --dest-root /var/www/site --dry-run --trace

Check archive structure:

bash
1unzip -l /path/to/backup.zip | head -50
2tar -tzf /path/to/backup.tar.gz | head -50

Verify wp-cli on destination:

bash
1ssh user@dest 'cd /var/www/site && wp core version'

Archive Adapter System

The script uses an extensible adapter system for different backup formats.

Supported Formats

1. Duplicator: ZIP archives with dup-installer/dup-database__*.sql structure
2. Jetpack Backup: ZIP/TAR.GZ archives with sql/*.sql multi-file structure
3. Solid Backups: ZIP archives with split SQL in wp-content/uploads/backupbuddy_temp/{ID}/

Adding New Adapters

See src/lib/adapters/README.md for contributor guide.

Each adapter must implement:

• validate_<adapter>() - Check if file matches format
• extract_<adapter>() - Extract archive to temp directory
• detect_db_<adapter>() - Find database file(s)
• detect_wp_content_<adapter>() - Find wp-content directory

Best Practices

When Assisting with Code Changes

1. Always check if source files need modification (src/) not wp-migrate.sh directly
2. Run make build after any source changes to regenerate wp-migrate.sh
3. Run ShellCheck validation before committing
4. Update CHANGELOG.md for all features and fixes
5. Use TodoWrite to track multi-step tasks
6. Create focused PRs addressing single concerns

When Testing Migrations

1. Always start with dry-run to preview operations
2. Use verbose mode for troubleshooting (--verbose or --trace)
3. Verify backups before destructive operations
4. Test rollback procedures in safe environments
5. Check logs in logs/ directory after migrations

When Creating Releases

1. Update CHANGELOG.md with version number and date
2. Create git tag with semantic version (e.g., v2.7.0)
3. Generate GitHub release with changelog excerpt
4. Verify tests pass on clean checkout
5. Update README if user-facing changes exist

Common Patterns

Searching Code

Use Grep tool for code searches:

pattern: "function_name"
output_mode: "content"
-n: true (show line numbers)

Reading Source Files

Use Read tool for file contents:

file_path: /Volumes/personal/codeprojects/bash/wp-migrate/src/lib/functions.sh

Editing Code

Use Edit tool for precise changes:

file_path: /Volumes/personal/codeprojects/bash/wp-migrate/src/lib/functions.sh
old_string: "exact match from file"
new_string: "replacement text"

Running Git Commands

bash
1git status
2git diff main...HEAD  # See all changes in branch
3git log main..HEAD    # See all commits in branch

Critical Reminders

• NEVER edit wp-migrate.sh directly - edit files in src/ instead
• ALWAYS run make build after source changes
• ALWAYS update CHANGELOG.md for features and fixes
• ALWAYS run ShellCheck before committing (make test)
• ALWAYS commit both source AND built files together
• ALWAYS review ALL commits when creating PRs (not just latest commit)
• ALWAYS use TodoWrite for multi-step tasks to track progress