grpc-server-reflection

gRPC server reflection for Node.js.

Using the reflection on your server allows your clients to get information regarding available RPCs and their format without actually having the schema definition.

With reflection you can use tools like grpcurl or wombat to call and test the API without linking the schema files, but just by accessing the live server.

Usage

The package adds a defined reflection service implementation to your server. The data about your schema is read from a descriptor set, which you can produce with your code generator.

Generate descriptor set

Generate descriptor set with grpc_tools_node_protoc using descriptor_set_out and include_imports, e.g.:

grpc_tools_node_protoc
    --descriptor_set_out=path/to/descriptor_set.bin
    --include_imports
    ./api/**/*.proto

Add reflection

import { Server } from '@grpc/grpc-js';
import { addReflection } from 'grpc-server-reflection'

const server = new Server()
addReflection(server, 'path/to/descriptor_set.bin')

Notes

• Reflection can be added before or after registering other services
• All services from descriptor set are available
• Server reflection service is not included (unless added manually in the descriptor set)
• Running tests requires grpc_cli

Thanks

This project is heavily inspired and ports some parts of code from nice-grpc-server-reflection. I respectfully burrowed some of the code based on encouragement from the author, to available solid server reflection for Node.js for general purpose. I tried to implement it myself but failed due to some incompatibilities with binary format in protobuf-js with the C++ implementation. Using descriptor sets avoids as in the referenced project avoids the issues.

See also

Here is a list and comparison with the similar projects:

| package | full support | @grpc/grpc-js support | grpc support | framework agnostic | service detection | | ------------------------------------------------------------------------------------------ | ------------ | ----------------------- | -------------- | ------------------ | ----------------- | | grpc-server-reflection | ✅️ | ✅️ | ✅️ | ✅️ | ✅️ | | nice-grpc-server-reflection | ✅️ | ✅️ | ❌ | ❌ | ❌ | | grpc-node-server-reflection | ❌ | ✅️ | ❌ | ❌ | ❌ | | grpc-reflection-js | ❌ | ✅️ | ❌ | ❌ | ❌ |

License

MIT