85 lines
1.8 KiB
Go
85 lines
1.8 KiB
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"math/rand"
|
||
|
|
"time"
|
||
|
|
|
||
|
|
"github.com/micro/go-micro/client"
|
||
|
|
"github.com/micro/go-micro/cmd"
|
||
|
|
c "github.com/micro/go-micro/context"
|
||
|
|
"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())
|
||
|
|
}
|
||
|
|
|
||
|
|
// A random node selector
|
||
|
|
func randomSelector(s []*registry.Service) (*registry.Node, error) {
|
||
|
|
if len(s) == 0 {
|
||
|
|
return nil, errors.NotFound("go.micro.client", "Service not found")
|
||
|
|
}
|
||
|
|
|
||
|
|
i := rand.Int()
|
||
|
|
j := i % len(s)
|
||
|
|
|
||
|
|
if len(s[j].Nodes) == 0 {
|
||
|
|
return nil, errors.NotFound("go.micro.client", "Service not found")
|
||
|
|
}
|
||
|
|
|
||
|
|
n := i % len(s[j].Nodes)
|
||
|
|
return s[j].Nodes[n], nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// Wraps the node selector so that it will log what node was selected
|
||
|
|
func wrapSelector(fn client.NodeSelector) client.NodeSelector {
|
||
|
|
return func(s []*registry.Service) (*registry.Node, error) {
|
||
|
|
n, err := fn(s)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
fmt.Printf("Selected node %v\n", n)
|
||
|
|
return n, nil
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
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",
|
||
|
|
})
|
||
|
|
|
||
|
|
// create context with metadata
|
||
|
|
ctx := c.WithMetadata(context.Background(), map[string]string{
|
||
|
|
"X-User-Id": "john",
|
||
|
|
"X-From-Id": "script",
|
||
|
|
})
|
||
|
|
|
||
|
|
rsp := &example.Response{}
|
||
|
|
|
||
|
|
// Call service
|
||
|
|
if err := client.Call(ctx, 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.Selector(wrapSelector(randomSelector)),
|
||
|
|
)
|
||
|
|
|
||
|
|
fmt.Println("\n--- Call example ---\n")
|
||
|
|
for i := 0; i < 10; i++ {
|
||
|
|
call(i)
|
||
|
|
}
|
||
|
|
}
|