README
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Metadata Service
Architecture Overview
The code follows Clean Architecture as described by Uncle Bob and depicted in the following diagram:
Entities Layer
The innermost layer, is the entities layer found in the entity package:
Entities encapsulate Enterprise wide business rules. An entity can be an object with methods, or it can be a set of data structures and functions. It doesn’t matter so long as the entities could be used by many different applications in the enterprise.
In this package we have the definition of our entities, and their respective unit tests.
Use Cases Layer
According to Uncle Bob:
The software in this layer contains application specific business rules. It encapsulates and implements all of the use cases of the system
Inside the usecase package, we implement the other business rules of our product.
We also find here the mocks generated by Gomock. The outermost layer of the
architecture will use them during the tests.
Interface Adapters Layer
HTTP API
The codes in this layer adapt and convert the data to the format used by the entities and use cases for external agents such as databases, web, etc.
In this application, UseCases are accessed through an HTTP API.
The api package is divided into three packages: handler, presenter, and middleware.
The handler package handles HTTP requests and responses, as well as using existing business rules in the usecases.
The presenters are responsible for formatting the data generated as a response by handlers. This gives us
control over how an entity will be delivered via the API.
In the last package of the API we find the middlewares, used by several endpoints, implementing cors and metrics.
GraphQL
Frameworks and Drivers layer
According to Uncle Bob:
The outermost layer is generally composed of frameworks and tools such as the Database, the Web Framework, etc. This layer is where all the details go.
For example, in the file infrastructure/repository/user_keyvalue.go we have the implementation of
the interface Repository for a KeyValue Store. If we need to change to another database, this
is where we would create the new implementation.
Support Packages
Support packages inside pkg, provide common functionality such as encryption, logging, file handling, etc. These
features are not part of the domain of our application, and all the layers can use them. Even other applications
can import and use these packages.
Directories