Overview

To make calls between themselves, SAF services use gRPC, for efficiency and backwards compatibility. Use @saflib/grpc to run gRPC service implementations.

Package Status

I haven't used gRPCs nearly as much as other packages in SAF, so gRPC packages are underdeveloped. I have an idea where to take them, but it will take some time and experimentation to get there.

TODOs:

• Figure out how to share generate.sh between packages.
• Nail down what rpc requests and responses should look like, particularly around errors.
• Figure out how to do integration tests without running a grpc server.

Package Structure

Each package which depends on @saflib/grpc should have the following structure:

{service-name}-grpc/
├── context.ts
├── grpc.ts
├── rpcs/
│   └── {service-1}/
│   │   ├── index.ts
│   │   ├── get-by-id.test.ts
│   │   ├── get-by-id.ts
│   │   └── ...
│   ├── {service-2}/
│   └── ...
├── package.json

Files and Directories Explained

context.ts

This file contains the AsyncLocalStorage used by rpcs the gRPC service.

See @saflib/express for more details.

grpc.ts

This file contains the gRPC service implementation. It should export a function which creates a grpc.Server instance. It should:

• Have all grpc services added to it with server.addService.
• Wrap all service implementations with addSafContext and any service-specific context with makeGrpcServerContextWrapper.

It should not start the server.

rpcs/

This directory contains the gRPC service implementations. Each service should have its own directory.

Each service should have an index.ts file which exports the service definition and implementation. Each method should have its own file which exports a function typed to the method.

Related Packages

Public

To specify the gRPC services a service provides, use @saflib/grpc-specs.