応用例：go-microを利用したマイクロサービスレコメンドシステムの構築

go get github.com/micro/go-micro/v2

mkdir -p feature_engineering
cd feature_engineering
go mod init feature_engineering

package main

import (
    "context"
    "github.com/micro/go-micro/v2"
    pb "github.com/username/recommender/protos"
    "log"
)

type FeatureEngineeringService struct{}

func (s *FeatureEngineeringService) ExtractFeatures(ctx context.Context, req *pb.ExtractFeaturesRequest, rsp *pb.ExtractFeaturesResponse) error {
    log.Printf("Extracting features for user %d", req.UserId)
    rsp.Features = []float32{0.1, 0.2, 0.3}
    return nil
}

func main() {
    // Create service
    service := micro.NewService(
        micro.Name("go.micro.service.feature_engineering"),
    )

    // Initialise service
    service.Init()

    // Register handler
    pb.RegisterFeatureEngineeringHandler(service.Server(), new(FeatureEngineeringService))

    // Run the server
    if err := service.Run(); err != nil {
        log.Fatal(err)
    }
}

docker run -p 2379:2379 -p 2380:2380 
    --name etcd 
    -v /tmp/etcd:/etcd-data 
    etcd:latest 
    /usr/local/bin/etcd 
    --name my-etcd-1 
    --data-dir /etcd-data 
    --advertise-client-urls http://0.0.0.0:2379 
    --listen-client-urls http://0.0.0.0:2379 
    --initial-advertise-peer-urls http://0.0.0.0:2380 
    --listen-peer-urls http://0.0.0.0:2380 
    --initial-cluster my-etcd-1=http://0.0.0.0:2380

import (
    "github.com/micro/go-micro/v2/registry"
    "github.com/micro/go-plugins/registry/etcdv3/v2"
)

// Create new registry
etcdRegistry := etcdv3.NewRegistry(
    registry.Addrs("127.0.0.1:2379"),
)

// Register service
if err := etcdRegistry.Register(service.Options().Service); err != nil {
    log.Fatal(err)
}

package main

import (
    "context"
    "fmt"
    "github.com/micro/go-micro/v2"
    "github.com/micro/go-micro/v2/registry"
    "github.com/micro/go-plugins/registry/etcdv3/v2"
    pb "github.com/username/recommender/protos"
)

func main() {
    // Create new registry
    etcdRegistry := etcdv3.NewRegistry(
        registry.Addrs("127.0.0.1:2379"),
    )

    // Create new service
    service := micro.NewService(
        micro.Registry(etcdRegistry),
    )

    // Initialise service
    service.Init()

    // Call feature engineering service
    featureEngineeringClient := pb.NewFeatureEngineeringService("go.micro.service.feature_engineering", service.Client())
    rsp, err := featureEngineeringClient.ExtractFeatures(context.TODO(), &pb.ExtractFeaturesRequest{UserId: 1})
    if err != nil {
        fmt.Println(err)
    }
    fmt.Printf("Features: %v", rsp.Features)
}