Vladislav0Art/cmake-project-template

Sample project that demonstrates a possible file structure and CMake configurations that are suitable for small-middle size personal projects.

C++ CMake Project Template

Sample project that demonstrates a possible file structure and CMake configurations that are suitable for small-middle size personal projects. The repository can be used as a starting point for a new project.

gRPC Interceptors

The project components:

1. include/components/ClientInterceptor/client-interceptor.hpp: contains the implementation of the client interceptor; this interceptor is responsible for attaching a JWT token to the request and tokens refreshing if the StatusCode::UNAUTHORIZED was returned by the server.
2. include/components/ServerInterceptor/server-interceptor.hpp: contains the implementation of the server interceptor; this interceptor is responsible for validating the JWT token. The server interceptor cannot prevent the endpoint accepting a request with an invalid token, therfore the interceptor creates a meta-field named x-user-id which indicates whether the token was valid. The endpoint should check the mentioned field and act accordingly: if it present allow access to the resource, otherwise cancel the operation. The interceptor memorizes that token was invalid, thus when the server endpoint returns, it changes the returning Status to be 1) StatusCode::UNAVAILABLE or 2) StatusCOde::Unauthorized depending on whether the should 1) retry the request or 2) should not.
3. src/proto: contains the definition of a single service MyService with a private endpoint PrivateResource.
4. include/services/MyServiceImpl/my-service-impl.hpp: contains the implementation of the service MyService; the implementation checks whether the x-user-id meta-field is present within the metadata coming with the request.
5. tests/client.cpp: contains an example of the client code; SampleClient class requests the endpoint and retries the request if one failed with UNAVAILABLE status code.

Read comments inside the source files to better understand the idea.

Warning: the implementation is likely not the way you should implement the gRPC JWT Auth in C++. AuthMetadataProcessor is likely to be more suitable for this (See this).

Order of events for the Client-Interceptors-Server comminucation: