This commit addresses all the high-priority tasks outlined in the TASKS.md file, significantly improving the application's observability, completing key features, and refactoring critical parts of the codebase.
### Observability
- **Centralized Logging:** Implemented a new structured, context-aware logging system using `zerolog`. A new logging middleware injects request-specific information (request ID, user ID, trace ID) into the logger, and all application logging has been refactored to use this new system.
- **Prometheus Metrics:** Added Prometheus metrics for database query performance by creating a GORM plugin that automatically records query latency and totals.
- **OpenTelemetry Tracing:** Fully instrumented all application services in `internal/app` and data repositories in `internal/data/sql` with OpenTelemetry tracing, providing deep visibility into application performance.
### Features
- **Analytics:** Implemented like, comment, and bookmark counting. The respective command handlers now call the analytics service to increment counters when these actions are performed.
- **Enrichment Tool:** Built a new, extensible `enrich` command-line tool to fetch data from external sources. The initial implementation enriches author data using the Open Library API.
### Refactoring & Fixes
- **Decoupled Testing:** Refactored the testing utilities in `internal/testutil` to be database-agnostic, promoting the use of mock-based unit tests and improving test speed and reliability.
- **Build Fixes:** Resolved numerous build errors, including a critical import cycle between the logging, observability, and authentication packages.
- **Search Service:** Fixed the search service integration by implementing the `GetWorkContent` method in the localization service, allowing the search indexer to correctly fetch and index work content.
This commit introduces a comprehensive set of foundational improvements to make the API more robust, secure, and observable.
The following features have been implemented:
- **Observability Stack:** A new `internal/observability` package has been added, providing structured logging with `zerolog`, Prometheus metrics, and OpenTelemetry tracing. This stack is fully integrated into the application's request pipeline.
- **Centralized Authorization:** A new `internal/app/authz` service has been created to centralize authorization logic. This service is now used by the `user`, `work`, and `comment` services to protect all Create, Update, and Delete operations.
- **Standardized Input Validation:** The previous ad-hoc validation has been replaced with a more robust, struct-tag-based system using the `go-playground/validator` library. This has been applied to all GraphQL input models.
- **Structured Error Handling:** A new set of custom error types has been introduced in the `internal/domain` package. A custom `gqlgen` error presenter has been implemented to map these domain errors to structured GraphQL error responses with specific error codes.
- **`updateUser` Endpoint:** The `updateUser` mutation has been fully implemented as a proof of concept for the new patterns, including support for partial updates and comprehensive authorization checks.
- **Test Refactoring:** The test suite has been significantly improved by decoupling mock repositories from the shared `testutil` package, resolving circular dependency issues and making the tests more maintainable.
This commit introduces a comprehensive observability stack to the application, addressing a key objective from the TODO list.
The following features have been implemented:
- **Centralized Logging:** Replaced the existing custom logger with `zerolog` for structured, leveled, and performant logging. The logger is configured to output human-friendly console logs in development and JSON logs in production.
- **Distributed Tracing:** Integrated OpenTelemetry to provide distributed tracing capabilities. A new middleware has been added to create spans for all incoming HTTP requests, and the trace context is propagated.
- **Prometheus Metrics:** Added Prometheus metrics to monitor HTTP request latency and total request counts. A new `/metrics` endpoint is exposed on port 9090 to serve these metrics.
- **Request ID:** Implemented a middleware to add a unique request ID to every incoming request and response, improving traceability.
The new observability components are encapsulated in the `internal/observability` package, and the existing `internal/platform/log` package has been refactored to be a backward-compatible wrapper around the new logger.
The main application entry point (`cmd/api/main.go`) has been updated to initialize and gracefully shut down the new observability components.
This change introduces a service layer to encapsulate the business logic
for each domain aggregate. This will make the code more modular,
testable, and easier to maintain.
The following services have been created:
- author
- bookmark
- category
- collection
- comment
- like
- tag
- translation
- user
The main Application struct has been updated to use these new services.
The integration test suite has also been updated to use the new
Application struct and services.
This is a work in progress. The next step is to fix the compilation
errors and then refactor the resolvers to use the new services.
This commit introduces a new application layer to the codebase, which decouples the GraphQL resolvers from the data layer. The resolvers now call application services, which in turn call the repositories. This change improves the separation of concerns and makes the code more testable and maintainable.
Additionally, this commit introduces dataloaders to solve the N+1 problem in the GraphQL resolvers. The dataloaders are used to batch and cache database queries, which significantly improves the performance of the API.
The following changes were made:
- Created application services for most of the domains.
- Refactored the GraphQL resolvers to use the new application services.
- Implemented dataloaders for the `Author` aggregate.
- Updated the `app.Application` struct to hold the application services instead of the repositories.
- Fixed a large number of compilation errors in the test files that arose from these changes.
There are still some compilation errors in the `internal/adapters/graphql/integration_test.go` file. These errors are due to the test files still trying to access the repositories directly from the `app.Application` struct. The remaining work is to update these tests to use the new application services.
This commit introduces a comprehensive enhancement of the application's analytics features, addressing performance, data modeling, and feature set.
The key changes include:
- **Performance Improvement:** The analytics repository now uses a database "UPSERT" operation to increment counters, reducing two separate database calls (read and write) into a single, more efficient operation.
- **New Metrics:** The `WorkStats` and `TranslationStats` models have been enriched with new, calculated metrics:
- `ReadingTime`: An estimation of the time required to read the work or translation.
- `Complexity`: A score representing the linguistic complexity of the text.
- `Sentiment`: A score indicating the emotional tone of the text.
- **Service Refactoring:** The analytics service has been refactored to support the new metrics. It now includes methods to calculate and update these scores, leveraging the existing linguistics package for text analysis.
- **GraphQL API Expansion:** The new analytics fields (`readingTime`, `complexity`, `sentiment`) have been exposed through the GraphQL API by updating the `WorkStats` and `TranslationStats` types in the schema.
- **Validation and Testing:**
- GraphQL input validation has been centralized and improved by moving from ad-hoc checks to a consistent validation pattern in the GraphQL layer.
- The test suite has been significantly improved with the addition of new tests for the analytics service and the data access layer, ensuring the correctness and robustness of the new features. This includes fixing several bugs that were discovered during the development process.
