feat: Docker branch isolation for parallel development

[matrixise]

Summary

This PR implements automatic environment isolation based on git branch names, allowing developers to work on multiple branches simultaneously without conflicts between databases, containers, or Docker volumes.

Key Features

🔄 Automatic Branch Detection

• Auto-detects current git branch and normalizes the name
• Uses branch name throughout Docker and database configuration
• Works seamlessly when switching branches

🐳 Docker Isolation

• Images: Tagged by branch (python.ie/website:{branch})
• Containers: Unique names (pythonie-{service}-{branch})
• Volumes: Isolated per branch (pythonie-postgres-data-{branch}, pythonie-redis-data-{branch})
• Databases: PostgreSQL (pythonie_{branch}) and SQLite (db-{branch}.sqlite3)

🛠️ New Commands

task branch:info      # Show current branch environment
task branch:verify    # Verify database configuration
task branch:volumes   # List all Docker volumes by branch
task branch:clean     # Remove volumes for current branch

📚 Documentation

• Comprehensive DOCKER-BRANCHES.md with usage examples and troubleshooting
• Updated README.md with "Docker Branch Isolation" section
• .env.example template for custom port overrides

Changes

Infrastructure

• docker-compose.yml: Dynamic image, container, database, and volume names based on GIT_BRANCH
• Taskfile.yaml: Auto-detect branch, generate .env file, new branch:* commands
• dev.py: SQLite databases now isolated by branch (db-{branch}.sqlite3)

Service Updates

• Upgraded Redis from 6.2 to 7-alpine with persistence
• Added healthchecks for PostgreSQL and Redis
• Removed unused minio and mc services
• Configurable ports for parallel development (WEB_PORT, PG_PORT)

Files Modified

• .gitignore - Added .env and *.sqlite3
• docker-compose.yml - Branch-based configuration
• Taskfile.yaml - Branch detection and new tasks
• pythonie/pythonie/settings/dev.py - SQLite isolation
• README.md - Complete documentation
• DOCKER-BRANCHES.md - Detailed usage guide
• .env.example - Configuration template

Use Cases

Parallel Development

# Terminal 1: Main branch
git checkout main
task run  # Port 8000, pythonie_main DB

# Terminal 2: Feature branch
git checkout feature/auth
WEB_PORT=8001 PG_PORT=5433 task run  # Port 8001, pythonie_feature-auth DB

Branch Switching

git checkout main
task run  # Automatically uses main database

git checkout feature/xyz
task run  # Automatically uses feature-xyz database (isolated from main)

Testing

Verified on branch feat/docker-branch-isolation:

• ✅ Docker images tagged correctly
• ✅ PostgreSQL database created with branch name
• ✅ SQLite database created with branch name
• ✅ Volumes isolated per branch
• ✅ Containers have unique names
• ✅ All task branch:* commands working
• ✅ Environment switching on git checkout

Breaking Changes

None. This is fully backward compatible:

• Default branch name is "dev" if detection fails
• Existing databases remain accessible
• No changes to production deployment

🤖 Generated with Claude Code

[matrixise]

I've converted this PR to draft status because I realize I've committed too many separate concerns together, which doesn't follow good PR practices.

I will split this work into separate PRs:

1. First PR: Docker Compose infrastructure updates

   • Upgrade Redis from 6.2 to 7-alpine
   • Add healthchecks for PostgreSQL and Redis
   • Remove unused minio/mc services
   • Other docker-compose.yml improvements

2. Second PR: Branch isolation feature

   • Automatic environment isolation by git branch
   • Branch-specific Docker images, databases, and volumes
   • New task branch:* commands
   • Documentation (DOCKER-BRANCHES.md, README updates)

This separation will make the changes easier to review and allow for incremental adoption.

I'll close this PR once the split PRs are ready.