add hystrix middleware

example/hystrix_example/main.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/afex/hystrix-go/hystrix"
+)
+
+func main() {
+	hystrix.ConfigureCommand("koala_rpc", hystrix.CommandConfig{
+		Timeout:               1000,
+		MaxConcurrentRequests: 100,
+		ErrorPercentThreshold: 25,
+	})
+
+	for {
+		err := hystrix.Do("get_baidu", func() error {
+			// talk to other services
+			_, err := http.Get("https://www.baidu.com/")
+			if err != nil {
+				fmt.Println("get error")
+				return err
+			}
+			return nil
+		}, func(err error) error {
+			fmt.Println("get an error, handle it, err:", err)
+			return err
+		})
+		if err == nil {
+			fmt.Printf("request success\n")
+		}
+		time.Sleep(time.Millisecond * 10)
+	}
+
+	time.Sleep(2 * time.Second) // 调用Go方法就是起了一个goroutine，这里要sleep一下，不然看不到效果
+}

go.mod

@@ -3,6 +3,7 @@ module github.com/ibinarytree/koala
 go 1.13
 
 require (
+	github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5
 	github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd // indirect
 	github.com/coreos/bbolt v1.3.3 // indirect
 	github.com/coreos/etcd v3.3.17+incompatible

go.sum

@@ -1,5 +1,7 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5 h1:rFw4nCn9iMW+Vajsk51NtYIcwSTkXr+JGrMd36kTDJw=
+github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5/go.mod h1:SkGFH1ia65gfNATL8TAiHDNxPzPdmEL5uirI2Uyuz6c=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=

middleware/hystrix.go

@@ -0,0 +1,27 @@
+package middleware
+
+import (
+	"context"
+
+	"github.com/afex/hystrix-go/hystrix"
+	"github.com/ibinarytree/koala/meta"
+)
+
+func HystrixMiddleware(next MiddlewareFunc) MiddlewareFunc {
+	return func(ctx context.Context, req interface{}) (interface{}, error) {
+
+		rpcMeta := meta.GetRpcMeta(ctx)
+		var resp interface{}
+
+		hystrixErr := hystrix.Do(rpcMeta.ServiceName, func() (err error) {
+			resp, err = next(ctx, req)
+			return err
+		}, nil)
+
+		if hystrixErr != nil {
+			return nil, hystrixErr
+		}
+
+		return resp, hystrixErr
+	}
+}

rpc/client.go

@@ -71,10 +71,13 @@ func (k *KoalaClient) getCaller(ctx context.Context) string {
 func (k *KoalaClient) buildMiddleware(handle middleware.MiddlewareFunc) middleware.MiddlewareFunc {
 
 	var mids []middleware.Middleware
+	mids = append(mids, middleware.HystrixMiddleware)
 	mids = append(mids, middleware.NewDiscoveryMiddleware(k.register))
+
 	mids = append(mids, middleware.NewLoadBalanceMiddleware(k.balance))
 	mids = append(mids, middleware.ShortConnectMiddleware)
-	m := middleware.Chain(mids[0], mids...)
+
+	m := middleware.Chain(mids[0], mids[1:]...)
 	return m(handle)
 
 }

tools/koala/client_example/main.go

@@ -4,6 +4,7 @@ package main
 
 import (
 	"context"
+	"time"
 
 	"github.com/ibinarytree/koala/logs"
 	"github.com/ibinarytree/koala/tools/koala/client_example/generate/client/helloc"
@@ -17,14 +18,24 @@ const (
 
 func main() {
 	client := helloc.NewHelloClient("hello")
-	ctx := context.Background()
-	resp, err := client.SayHello(ctx, &hello.HelloRequest{Name: "test my client"})
-	if err != nil {
-		logs.Error(ctx, "could not greet: %v", err)
-		logs.Stop()
-		return
-	}
+	var count int
+	for {
+		count++
+		ctx := context.Background()
+		resp, err := client.SayHello(ctx, &hello.HelloRequest{Name: "test my client"})
+		if err != nil {
+			if count%100 == 0 {
+				logs.Error(ctx, "could not greet: %v", err)
+			}
+			time.Sleep(10 * time.Millisecond)
+			continue
+		}
+
+		if count%100 == 0 {
+			logs.Info(ctx, "Greeting: %s", resp.Reply)
+		}
 
-	logs.Info(ctx, "Greeting: %s", resp.Reply)
+		time.Sleep(100 * time.Millisecond)
+	}
 	logs.Stop()
 }

tools/koala/output/conf/test/hello.yaml

@@ -1,7 +1,7 @@
-port: 8080
+port: 8090
 prometheus:
   switch_on: true
-  port: 8081
+  port: 8091
 service_name: hello
 register:
   switch_on: true