feat: add example client

Signed-off-by: Zufar Dhiyaullhaq <[email protected]>

client/main.go

@@ -1 +1,46 @@
 package main
+
+import (
+	"context"
+	"log"
+
+	pbcloudevents "github.com/cloudevents/sdk-go/binding/format/protobuf/v2"
+	cloudevents "github.com/cloudevents/sdk-go/v2"
+	cehttp "github.com/cloudevents/sdk-go/v2/protocol/http"
+	model "github.com/gopaytech/istio-upgrade-proto/upgrade"
+)
+
+func main() {
+	ctx := cloudevents.ContextWithTarget(context.Background(), "http://localhost:8080/v1/upgrade")
+
+	p, err := cloudevents.NewHTTP()
+	if err != nil {
+		log.Fatalf("failed to create protocol: %s", err.Error())
+	}
+
+	c, err := cloudevents.NewClient(p, cloudevents.WithTimeNow(), cloudevents.WithUUIDs())
+	if err != nil {
+		log.Fatalf("failed to create client, %v", err)
+	}
+
+	data := &model.Upgrade{
+		IstioVersion: "1.22.4",
+		ClusterName:  "s-go-sy-primary-gke-01",
+	}
+	e := cloudevents.NewEvent()
+	e.SetType("upgrade-event")
+	e.SetSource("testing-client")
+	_ = e.SetData(pbcloudevents.ContentTypeProtobuf, data)
+
+	res := c.Send(ctx, e)
+	if cloudevents.IsUndelivered(res) {
+		log.Printf("Failed to send: %v", res)
+	} else {
+		var httpResult *cehttp.Result
+		if cloudevents.ResultAs(res, &httpResult) {
+			log.Printf("Sent with status code %d", httpResult.StatusCode)
+		} else {
+			log.Printf("Send did not return an HTTP response: %s", res)
+		}
+	}
+}