Istio integration (#421)

This the very first step for fission to integrate with Istio, which is an open platform to connect, manage, and secure microservices. With Istio, users are able to monitor functions usage and trace requests latency through dashboards. For more information, please visit http://fission.io/docs/

environments/fetcher/client/client.go

@@ -5,9 +5,7 @@ import (
 	"encoding/json"
 	"io/ioutil"
 	"log"
-	"net"
 	"net/http"
-	"net/url"
 	"time"
 
 	"github.com/fission/fission"
@@ -38,29 +36,25 @@ func (c *Client) Fetch(fr *fetcher.FetchRequest) error {
 	for i := 0; i < maxRetries; i++ {
 		resp, err = http.Post(c.url, "application/json", bytes.NewReader(body))
 
-		if err == nil && resp.StatusCode == 200 {
-			defer resp.Body.Close()
-			return nil
-		}
-
-		// Only retry for the specific case of a connection error.
-		if urlErr, ok := err.(*url.Error); ok {
-			if netErr, ok := urlErr.Err.(*net.OpError); ok {
-				if netErr.Op == "dial" {
-					if i < maxRetries-1 {
-						time.Sleep(50 * time.Duration(2*i) * time.Millisecond)
-						continue
-					}
-				}
+		if err == nil {
+			if resp.StatusCode == 200 {
+				resp.Body.Close()
+				return nil
 			}
+			err = fission.MakeErrorFromHTTP(resp)
 		}
+
+		if i < maxRetries-1 {
+			time.Sleep(50 * time.Duration(2*i) * time.Millisecond)
+			log.Printf("Error fetching package (%v), retrying", err)
+			continue
+		}
+
+		log.Printf("Failed to fetch: %v", err)
+		return err
 	}
 
-	if err == nil {
-		err = fission.MakeErrorFromHTTP(resp)
-	}
-	log.Printf("Failed to fetch: %v", err)
-	return err
+	return nil
 }
 
 func (c *Client) Upload(fr *fetcher.UploadRequest) (*fetcher.UploadResponse, error) {

environments/fetcher/cmd/main.go

@@ -128,15 +128,6 @@ func specializePod(f *fetcher.Fetcher, fetchPayload *string, loadPayload *string
 		if err == nil && resp.StatusCode < 300 {
 			// Success
 			resp.Body.Close()
-			//On Success creates a file which is used as a readiness probe by Kubernetes for this container/pod
-			file, err := os.OpenFile("/tmp/ready", os.O_RDONLY|os.O_CREATE, 0666)
-			if err != nil {
-				log.Fatalf("Error creating readiness file: %v", err)
-			}
-			err = file.Close()
-			if err != nil {
-				log.Fatalf("Error closing readiness file: %v", err)
-			}
 			break
 		}