Extracted the monolithic import_source() function (776 lines) into focused,
testable components with clear single responsibilities:
- BlocklistDownloader: HTTP download with exponential backoff retry logic
* Handles transient failures (429, 5xx errors, timeouts)
* Configurable retry attempts and backoff strategy
* 93% test coverage
- BlocklistParser: Parse and validate IP addresses
* Extract valid IPv4/IPv6 addresses from text
* Skip CIDRs and malformed entries gracefully
* Separate parsing from validation concerns
* 100% test coverage
- BanExecutor: Ban execution with error handling
* Ban IPs via fail2ban socket
* Stop on JailNotFoundError (jail doesn't exist)
* Continue on JailOperationError (individual ban failures)
* 100% test coverage
- BlocklistImportWorkflow: Thin orchestrator
* Coordinates the download → parse → ban → log flow
* Pre-warms geo cache with newly banned IPs
* 96% test coverage
- blocklist_service.py: Maintains public API
* Source CRUD (create, read, update, delete)
* URL validation and preview functionality
* Scheduling configuration and import triggers
* 92% test coverage
Benefits:
* Each component is independently testable with mock dependencies
* Error handling is explicit and localized
* Components can evolve independently
* Logging is contextual and clear
* Retry and transient error handling are isolated
Testing:
* All 36 existing blocklist_service tests pass
* All 13 blocklist import task tests pass
* Added 17 comprehensive component unit tests
* Combined 96%+ coverage on new modules
* Zero type errors in new code
Documentation:
* Updated Refactoring.md with detailed architecture notes
* Added component architecture diagram to Architekture.md
* Documented ownership and responsibilities of each component
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
