NestJS - grpc 微服务中的元数据

Question

I am looking for a way to authorize an rpc via NestJS grpc microservices. Basically I want to attach a token in the grpc client, which has to be validated by the grpc server. I found this issue , but I did not get where exactly grpc.Metadata pass as a second argument.

Answer 1

I found a way to solve this. For sure not the most elegant solution, but it works for now. A simplified example:

// gRPC client
@Get(':id')
async call(@Param() params) {
    const metadata = new grpc.Metadata();
    // add relevant data to the metadata object (e.g from request header)
    metadata.add('role', 'admin');
    return this.userService.findOne({ id: +params.id}, metadata);
}

// Service
interface UserService {
    findOne(data: {id: number}, metadata: grpc.Metadata): Observable<any>;
}

// gRPC server
@GrpcMethod('UserService', 'FindOne')
async findOne(data: UserById, metadata: grpc.Metadata) {
    const meta = metadata.getMap();
    // do something with the metadata...
    console.log(meta.role);
    const items: User= [
        { id: 1, name: 'User 1' },
        { id: 2, name: 'User 2' },
        { id: 3, name: 'User 3' },
    ];
    return items.find(({ id }) => id === data.id);
}