Improve NGINX start

For NGINX and NGINX Plus:
- After the IC starts NGINX, check that NGINX is running by
querying the config version via the unix socket -- the same check
that is performed after each configuration reload.
- Modify the check to always sleep before the first check.

For NGINX Plus:
- Remove no longer required 0.5s timeout during the IC start.

cmd/nginx-ingress/main.go

@@ -229,7 +229,6 @@ func main() {
 
 	var nginxAPI *plus.NginxAPIController
 	if *nginxPlus {
-		time.Sleep(500 * time.Millisecond)
 		httpClient := getSocketClient()
 		nginxAPI, err = plus.NewNginxAPIController(&httpClient, "http://nginx-plus-api/api", local)
 		if err != nil {

internal/nginx/nginx.go

@@ -319,18 +319,26 @@ func (nginx *Controller) Reload() error {
 
 // Start starts NGINX
 func (nginx *Controller) Start(done chan error) {
-	if !nginx.local {
-		cmd := exec.Command("nginx")
-		cmd.Stdout = os.Stdout
-		cmd.Stderr = os.Stderr
-		if err := cmd.Start(); err != nil {
-			glog.Fatalf("Failed to start nginx: %v", err)
-		}
-		go func() {
-			done <- cmd.Wait()
-		}()
-	} else {
-		glog.V(3).Info("Starting nginx")
+	glog.V(3).Info("Starting nginx")
+
+	if nginx.local {
+		return
+	}
+
+	cmd := exec.Command("nginx")
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Start(); err != nil {
+		glog.Fatalf("Failed to start nginx: %v", err)
+	}
+
+	go func() {
+		done <- cmd.Wait()
+	}()
+
+	err := nginx.verifyClient.WaitForCorrectVersion(nginx.configVersion)
+	if err != nil {
+		glog.Fatalf("Could not get newest config version: %v", err)
 	}
 }
 

internal/nginx/verify/client.go

@@ -60,16 +60,18 @@ func (c *Client) WaitForCorrectVersion(expectedVersion int) error {
 	// This value needs tuning.
 	maxRetries := 160
 	sleep := 25 * time.Millisecond
-	for i := 0; i < maxRetries; i++ {
+	for i := 1; i <= maxRetries; i++ {
+		time.Sleep(sleep)
+
 		version, err := c.GetConfigVersion()
 		if err != nil {
-			return fmt.Errorf("unable to fetch version: %v", err)
+			glog.V(3).Infof("Unable to fetch version: %v", err)
+			continue
 		}
 		if version == expectedVersion {
 			glog.V(3).Infof("success, version %v ensured. iterations: %v. took: %v", expectedVersion, i, time.Duration(i)*sleep)
 			return nil
 		}
-		time.Sleep(sleep)
 	}
 	return fmt.Errorf("could not get expected version: %v", expectedVersion)
 }