# Health Checks, Reflection and Tools — gRPC

Source: https://www.skillbyai.com/en/grpc/e-tooling

> Operating and exploring services.

## Standard services and CLIs

The standard **health checking protocol** (`grpc.health.v1.Health` with `Check` and `Watch`) reports whether a server or a specific service is serving; Kubernetes supports native gRPC probes that use it. **Server reflection** lets tools discover services and message types at runtime, which is handy in development but often disabled in production. Tools: **grpcurl** (curl for gRPC), grpcui, Postman, BloomRPC-style GUIs, and `buf curl`.

## Exploring a service with grpcurl and probing health

Commands and a Kubernetes probe.

```bash
# list services (requires server reflection) and call a method
grpcurl -plaintext localhost:50051 list
grpcurl -plaintext -d '{"id": "o-1001"}' localhost:50051 shop.v1.OrderService/GetOrder

# check health
grpcurl -plaintext -d '{"service": "shop.v1.OrderService"}' localhost:50051 grpc.health.v1.Health/Check

# Kubernetes container spec (native gRPC probe)
# livenessProbe:
#   grpc:
#     port: 50051
```

## Use proto files when reflection is off

grpcurl can load .proto files with -import-path and -proto instead of relying on reflection.

**Quiz:** What does gRPC server reflection enable?

- [ ] Automatic retries
- [x] Tools can discover services and message types at runtime
- [ ] TLS certificate rotation
- [ ] Database migrations

*Answer:* Tools can discover services and message types at runtime. Useful for grpcurl and GUIs.