go-grpc-client-lb

README

go-grpc-client-lb

Example of gRPC client-side load balancing in Golang

Services

• gRPC server
• gRPC client

---

Build

1. Server

   make build-server
   # or
   go build -o grpc-server ./server
   

2. Client

   make build-client
   # or
   go build -o grpc-client ./client
   

---

Run

1. Run server

   make run-server
   # or
   ./grpc-server
   

2. In another shell, run client

   make run-client
   # or
   ./grpc-client
   

From source

1. Run server

   make run-server-src
   # or
   protoc --proto_path=./proto/ --go_out=plugins=grpc:domain ./proto/*
   GO111MODULE=on go run ./server/main.go
   

2. In another shell, run client

   make run-client-src
   # or
   protoc --proto_path=./proto/ --go_out=plugins=grpc:domain ./proto/*
   GO111MODULE=on go run ./client/main.go
   

---

Docker

Build

1. Server

   make container-build-server
   # or
   docker build -t grpc/grpc-server -f server.Dockerfile .
   

2. Client

   make container-build-client
   # or
   docker build -t grpc/grpc-client -f client.Dockerfile .
   

Run

1. Run server

   make container-run-server
   # or
   docker run -ti --rm --name server -p 50051:50051 grpc/grpc-server
   

2. In another shell, run client

   make container-run-client
   # or
   docker run -ti --rm --name client grpc/grpc-client
   

---

Kubernetes

Import container images

Minikube

1. Enable Minikube internal container registry

   eval $(minikube docker-env)
   

2. Build container images normally as it would be locally

KinD

1. Build container images normally as it would be locally

2. Import in KinD

   make load-container-kind
   # or
   kind load docker-image grpc/grpc-server
   kind load docker-image grpc/grpc-client
   

Deploy

1. Start Kubernetes locally

   • Minikube

     make start-minikube
     # or
     minikube start --cpus 4 --memory 8192 --disk-size=10g
     

   • Kind

     make start-kind
     # or
     kind create cluster --wait=60s
     

2. Deploy server

   make deploy-server
   # or
   kubectl apply -k kube/server
   

3. Deploy client

   make deploy-client
   # or
   kubectl apply -k kube/client
   

4. Take a look of logs

   • Server

     make server-logs
     # or
     kubectl logs -l app=grpc-server -f
     

   • (In another shell) Client

     make client-logs
     # or
     kubectl logs -l app=grpc-client -f
     

Cleanup

Minikube

make stop-minikube
# or
minikube stop
minikube delete

KinD

make stop-kind
# or
kind delete cluster

---

Example

1. Run server

   go run example/server/main.go
   

2. In another shell, run client

   go run example/client/main.go
   

---

Links

• https://grpc.io/blog/loadbalancing/
• https://github.com/grpc/grpc-go/tree/master/examples/features/load_balancing
• https://github.com/grpc/grpc/blob/master/doc/service_config.md
• https://medium.com/@ammar.daniel/grpc-client-side-load-balancing-in-go-cd2378b69242
• https://www.marwan.io/blog/grpc-dns-load-balancing