ms-auth/internal/transport/interceptors.go

package transport

import (
	"context"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

type ReqWithToken interface {
	GetToken() string
}

func (s *AuthServer) AuthInterceptor() grpc.UnaryServerInterceptor {
	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
		reqWithToken, ok := req.(ReqWithToken)
		if !ok {
			return nil, status.Errorf(codes.Unauthenticated, "")
		}
		token := reqWithToken.GetToken()

		userId, err := s.sessionService.Read(ctx, token)
		if err != nil {
			return nil, status.Errorf(codes.Unauthenticated, "")
		}

		user, err := s.userService.ReadUser(ctx, *userId)
		if err != nil {
			return nil, status.Errorf(codes.Unauthenticated, "")
		}

		ctx = context.WithValue(ctx, "user", user)

		return handler(ctx, req)
	}
}