Documentation: Creating and communicating with microservices.

User Story

There are multiple ways to set up microservices:

• Have a public facing API Gateway responsible for authentication, that then acts as a proxy for internal microservices, or which can have orchestration logic on top of their responses.
• Have many public facing services- one responsible for the process of authentication and the frontends are responsible for knowing.

There are also multiple ways to perform communication:

• Loopback 4 supports creating an OpenAPI JSON based datasource when using lb4 service.
• HTTP REST
• rpc, gRPC, redis/socket notifications.

There are different ways to organize the source code:

• A monorepository, using something like lerna to manage versioning and publishing.
• Separate repositories managed by different teams.

It would be great to have documentation and examples that could cover these cases. Example:

• Creating a loopback4 microservice as a REST Server that can expose an openapi.json file, and a loopback4 api gateway responsible for authentication and consuming those microservices.
• Creating a loopback4 microservice as a gRPC server that can publish proto files (to a private repository, or just on github for consumption), and a loopback4 api gateway responsible for authenticating and consuming those microservices.
• Workflows for maintaining multiple services with minimal manual code intervention.

Bắt đầu bằng việc xem lại tài liệu LoopBack 4 hiện có về lb4 service và các datasource JSON của OpenAPI. Xác định phạm vi cho các ví dụ bao quát microservice REST và gRPC, API gateway, xác thực, tổ chức dịch vụ và workflow nhiều dịch vụ. Công việc được xem là hoàn tất khi các trường hợp được chọn có tài liệu đầy đủ và các ví dụ có thể chạy được, nhưng issue không xác định các tệp hoặc kiểm thử cần cập nhật.