micro/examples/client/node_selector/node_selector.go

88 lines
1.8 KiB
Go

package main
import (
"fmt"
"math/rand"
"time"
"github.com/micro/go-micro/client"
"github.com/micro/go-micro/cmd"
"github.com/micro/go-micro/errors"
example "github.com/micro/go-micro/examples/server/proto/example"
"github.com/micro/go-micro/registry"
"golang.org/x/net/context"
)
func init() {
rand.Seed(time.Now().Unix())
}
// Built in random hashed node selector
type nodeSelector struct {
r registry.Registry
}
func (n *nodeSelector) Retrieve(ctx context.Context, req client.Request) (*registry.Node, error) {
service, err := n.r.GetService(req.Service())
if err != nil {
return nil, errors.InternalServerError("go.micro.client", err.Error())
}
if len(service) == 0 {
return nil, errors.NotFound("go.micro.client", "Service not found")
}
i := rand.Int()
j := i % len(service)
if len(service[j].Nodes) == 0 {
return nil, errors.NotFound("go.micro.client", "Service not found")
}
k := i % len(service[j].Nodes)
return service[j].Nodes[k], nil
}
func (n *nodeSelector) Response(node *registry.Node, err error) {
return
}
func (n *nodeSelector) Reset() {
return
}
// Return a new random node selector
func RandomSelector(r registry.Registry) client.NodeSelector {
return &nodeSelector{r}
}
func call(i int) {
// Create new request to service go.micro.srv.example, method Example.Call
req := client.NewRequest("go.micro.srv.example", "Example.Call", &example.Request{
Name: "John",
})
rsp := &example.Response{}
// Call service
if err := client.Call(context.Background(), req, rsp); err != nil {
fmt.Println("call err: ", err, rsp)
return
}
fmt.Println("Call:", i, "rsp:", rsp.Msg)
}
func main() {
cmd.Init()
client.DefaultClient = client.NewClient(
client.Select(RandomSelector),
)
fmt.Println("\n--- Call example ---\n")
for i := 0; i < 10; i++ {
call(i)
}
}