grpc-lab

This repository contains various experiment related to grpc in golang. The setup per experiment is described in the experiments section below

The contracts directory contain a submodule which points to the grpc-lab-contracts repo

The repo uses buf to generate the definitions. The contracts repo contains the buf modules. buf generate and work files are contained in this repo

You need to have the following protobuf tools in your path before you generate go structs from proto definitions

Protoc Gen for go

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

Protoc Gen for go-grpc

go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

Grpc Gateway tools

go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway@latest

go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-openapiv2@latest

The generated files are contained in the generated directory. To regenerate the proto definitions use the following command buf generate

Experiments

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Client Side Load Balancing experiment

The repo contains a launcher script at the root start.sh The script assumes a running zookeeper instance on localhost:2181.

Its start 3 grpcs servers on port 5001, 5002 and 5003

The repo also contains a clinet which start with a zookeeper resolver in a round robin strategy

Test

The repo contains an integration test balancer_test.go It contain two tests

• PingTest : This test sping up a clinet and make 100 pings to the server based on different accountId (just some metadata). Based on this metadata the balancer chooses which server the ping should be routed too
• ChatTest : It works same as ping test except the rpc used underneath uses bi-di streaming

TODO

• Add better tests
• Better error handling for zookeeper
• Add more examples using etcd/consul etc

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Http Transcoding using grpc gateway (Mongo go driver support as well)

Implemented a book service which is a basic in memory CRUD application. The primary thing is this book servce get exposes as an http service using grpc-gateway transcoding

To run this service you need to you need to build the repo using

go build -o lab

Once build you can run the bookstore example using

./lab bookstore --port=<port_of_grpc_server> --clientPort=<port_for_grpc_gateway_reverse_proxy>

Once running you it exposes following http endpoints

• GET /api/v1/books - List of Books
• GET /api/v1/books/{id} - Get a book
• DELETE /api/v1/books/{id}" - Delete a book
• POST /api/v1/books - Create a book Payload - '{"title":"Designing Data Intensive Applications", "author":"Michael Kleppman"}'