nats-grpc-adaptor

NATS protoc-gen is a protoc plugin that simplifies the generation of NATS microservices by wrapping gRPC services.

Why Use This Plugin?

This project leverages NATS as the primary communication layer while utilizing its built-in service discovery capabilities. It enables developers to create unified services accessible directly through gRPC or as a NATS microservice.

Build Instructions

To build the plugin, simply run:

make build

Installing the Plugin

You can install the latest version of the plugin using the following command:

go install github.com/jenmud/protoc-gen-go-nats-grpc-adaptor@latest

It is recommended to install goimports and run it after generating the plugin files:

go install golang.org/x/tools/cmd/goimports@latest

Example Usage of goimports

To fix all files automatically:

goimports -w .

To fix only the generated proto files:

goimports -w ./example/example-nats-grpc-adaptor.pb.go

Using the Plugin

To use the plugin, run the protoc compiler with the following command. Ensure that protoc-gen-go-nats-grpc-adaptor is in your $PATH:

# Assuming the binary is located under ./builds after running `make build`
PATH=./builds:$PATH protoc \
--proto_path=./example \
--go_out=./example \
--go_opt=paths=source_relative \
--go-nats-grpc-adaptor_out=./example \
--go-nats-grpc-adaptor_opt=paths=source_relative \
--go-grpc_out=./example \
--go-grpc_opt=paths=source_relative \
example.proto messages.proto

Debugging

To enable debug logging, set the following environment variable:

export NATS_GRPC_ADAPTOR_DEBUG=true

The command above builds the example directory. Modify the command to point to your protobuf files as needed.

Querying NATS Using the CLI Client

You can query NATS services using the NATS CLI client:

./nats micro list

Example Output: Listing Microservices

# All Micro Services

| Name          | Version | ID                     | Description                                       |
|---------------|---------|------------------------|---------------------------------------------------|
| GreeterServer | 0.0.1   | TWaLR1B60j04SCblXqY1xP | NATS micro service adaptor wrapping GreeterServer |

Fetching Microservice Information

To fetch details about a specific microservice:

./nats micro info GreeterServer

Example Output: Microservice Information

Service Information

          Service: GreeterServer (TWaLR1B60j04SCblXqY1xP)
      Description: NATS micro service adaptor wrapping GreeterServer
          Version: 0.0.1

Endpoints:

               Name: Greeter
            Subject: svc.greeter.sayhello
        Queue Group: demo

               Name: Greeter
            Subject: svc.greeter.sayhelloagain
        Queue Group: demo

               Name: Greeter
            Subject: svc.greeter.saygoodbye
        Queue Group: demo

Statistics for 3 Endpoint(s):

  Greeter Endpoint Statistics:

           Requests: 1 in group "demo"
    Processing Time: 53µs (average 53µs)
            Started: 2024-11-17 16:40:49 (1m4s ago)
             Errors: 0

  Greeter Endpoint Statistics:

           Requests: 1 in group "demo"
    Processing Time: 25µs (average 25µs)
            Started: 2024-11-17 16:40:49 (1m4s ago)
             Errors: 1
         Last Error: 500:some random example error

  Greeter Endpoint Statistics:

           Requests: 1 in group "demo"
    Processing Time: 17µs (average 17µs)
            Started: 2024-11-17 16:40:49 (1m4s ago)
             Errors: 0