Merge pull request #34 from Comcast/feature/dnsReady

make requests to insure dns is ready before preceding.

src/caduceus/caduceus.go

@@ -206,6 +206,12 @@ func caduceus(arguments []string) int {
 		return 1
 	}
 
+	// make sure dns is ready before preceeding
+	dnsReadyChan := make(chan bool, 1)
+	go caduceusHealth.dnsReady(selfURL.String(), dnsReadyChan)
+	<- dnsReadyChan
+	logger.Debug("DNS ready")
+
 	webhookFactory.PrepareAndStart()
 
 	logger.Info("Caduceus is up and running!")

src/caduceus/caduceus_type.go

@@ -6,6 +6,7 @@ import (
 	"github.com/Comcast/webpa-common/logging"
 	"github.com/Comcast/webpa-common/secure"
 	"github.com/Comcast/webpa-common/secure/key"
+	"net/http"
 	"time"
 )
 
@@ -105,6 +106,23 @@ func (ch *CaduceusHealth) IncrementBucket(inSize int) {
 	}
 }
 
+func (ch *CaduceusHealth) dnsReady(address string, ready chan bool) {	
+	req, err := http.NewRequest("GET", address, nil)
+	if err != nil {
+		return
+	}
+	client := http.Client{}
+
+	var resp *http.Response
+	for resp == nil {
+		resp, err = client.Do(req)
+		if err == nil {
+			ready <- true
+			break
+		}
+	}
+}
+
 // Below is the struct and implementation of our worker pool factory
 type WorkerPoolFactory struct {
 	NumWorkers int