Added configuration option to change the probe's listen address.

Change-Id: I7e8aa7bf4a4756f12211e7108cabcdc86aacd78a
diff --git a/common/probe/probe.go b/common/probe/probe.go
index fdb07e8..8a8e485 100644
--- a/common/probe/probe.go
+++ b/common/probe/probe.go
@@ -207,7 +207,7 @@
 }
 
 // ListenAndServe implements 3 HTTP endpoints on the given port for healthz, readz, and detailz. Returns only on error
-func (p *Probe) ListenAndServe(port int) {
+func (p *Probe) ListenAndServe(address string) {
 	mux := http.NewServeMux()
 
 	// Returns the result of the readyFunc calculation
@@ -219,7 +219,7 @@
 	// Returns the details of the services and their status as JSON
 	mux.HandleFunc("/detailz", p.detailzFunc)
 	s := &http.Server{
-		Addr:    fmt.Sprintf(":%d", port),
+		Addr:    address,
 		Handler: mux,
 	}
 	log.Fatal(s.ListenAndServe())
diff --git a/ro_core/config/config.go b/ro_core/config/config.go
index be78228..28cde01 100644
--- a/ro_core/config/config.go
+++ b/ro_core/config/config.go
@@ -43,6 +43,7 @@
 	default_ROCoreCert            = "pki/voltha.crt"
 	default_ROCoreCA              = "pki/voltha-CA.pem"
 	default_Affinity_Router_Topic = "affinityRouter"
+	default_ProbeHost             = ""
 	default_ProbePort             = 8080
 )
 
@@ -66,6 +67,7 @@
 	ROCoreCert          string
 	ROCoreCA            string
 	AffinityRouterTopic string
+	ProbeHost           string
 	ProbePort           int
 }
 
@@ -93,6 +95,7 @@
 		ROCoreCert:          default_ROCoreCert,
 		ROCoreCA:            default_ROCoreCA,
 		AffinityRouterTopic: default_Affinity_Router_Topic,
+		ProbeHost:           default_ProbeHost,
 		ProbePort:           default_ProbePort,
 	}
 	return &roCoreFlag
@@ -142,6 +145,9 @@
 	help = fmt.Sprintf("Show version information and exit")
 	flag.BoolVar(&cf.DisplayVersionOnly, "version", default_DisplayVersionOnly, help)
 
+	help = fmt.Sprintf("The address on which to listen to answer liveness and readiness probe queries over HTTP.")
+	flag.StringVar(&(cf.ProbeHost), "probe_host", default_ProbeHost, help)
+
 	help = fmt.Sprintf("The port on which to listen to answer liveness and readiness probe queries over HTTP.")
 	flag.IntVar(&(cf.ProbePort), "probe_port", default_ProbePort, help)
 
diff --git a/ro_core/main.go b/ro_core/main.go
index 27ada02..a8508b8 100644
--- a/ro_core/main.go
+++ b/ro_core/main.go
@@ -241,7 +241,7 @@
 	 * objects there can be a single probe end point for the process.
 	 */
 	p := &probe.Probe{}
-	go p.ListenAndServe(ro.config.ProbePort)
+	go p.ListenAndServe(fmt.Sprintf("%s:%d", ro.config.ProbeHost, ro.config.ProbePort))
 
 	// Add the probe to the context to pass to all the services started
 	probeCtx := context.WithValue(ctx, probe.ProbeContextKey, p)
diff --git a/rw_core/config/config.go b/rw_core/config/config.go
index f9f1d3e..5f4a0e0 100644
--- a/rw_core/config/config.go
+++ b/rw_core/config/config.go
@@ -54,6 +54,7 @@
 	default_CorePairTopic             = "rwcore_1"
 	default_MaxConnectionRetries      = -1 // retries forever
 	default_ConnectionRetryInterval   = 2  // in seconds
+	default_ProbeHost                 = ""
 	default_ProbePort                 = 8080
 )
 
@@ -89,6 +90,7 @@
 	CorePairTopic             string
 	MaxConnectionRetries      int
 	ConnectionRetryInterval   int
+	ProbeHost                 string
 	ProbePort                 int
 }
 
@@ -128,6 +130,7 @@
 		CorePairTopic:             default_CorePairTopic,
 		MaxConnectionRetries:      default_MaxConnectionRetries,
 		ConnectionRetryInterval:   default_ConnectionRetryInterval,
+		ProbeHost:                 default_ProbeHost,
 		ProbePort:                 default_ProbePort,
 	}
 	return &rwCoreFlag
@@ -216,6 +219,9 @@
 	help = fmt.Sprintf("The number of seconds between each connection retry attempt ")
 	flag.IntVar(&(cf.ConnectionRetryInterval), "connection_retry_interval", default_ConnectionRetryInterval, help)
 
+	help = fmt.Sprintf("The host on which to listen to answer liveness and readiness probe queries over HTTP.")
+	flag.StringVar(&(cf.ProbeHost), "probe_host", default_ProbeHost, help)
+
 	help = fmt.Sprintf("The port on which to listen to answer liveness and readiness probe queries over HTTP.")
 	flag.IntVar(&(cf.ProbePort), "probe_port", default_ProbePort, help)
 
diff --git a/rw_core/main.go b/rw_core/main.go
index 6f06576..2311029 100644
--- a/rw_core/main.go
+++ b/rw_core/main.go
@@ -276,7 +276,7 @@
 	 * objects there can be a single probe end point for the process.
 	 */
 	p := &probe.Probe{}
-	go p.ListenAndServe(rw.config.ProbePort)
+	go p.ListenAndServe(fmt.Sprintf("%s:%d", rw.config.ProbeHost, rw.config.ProbePort))
 
 	// Add the probe to the context to pass to all the services started
 	probeCtx := context.WithValue(ctx, probe.ProbeContextKey, p)