apps: change to getting listenspec from context.

Change-Id: Ie90f21b83a0ee7b1744fd564af273bc28069e8c6
diff --git a/rps/rpsbot/main.go b/rps/rpsbot/main.go
index 98986a8..80d0331 100644
--- a/rps/rpsbot/main.go
+++ b/rps/rpsbot/main.go
@@ -17,7 +17,7 @@
 	"v.io/core/veyron2/vlog"
 
 	"v.io/core/veyron/lib/signals"
-	"v.io/core/veyron/profiles/roaming"
+	_ "v.io/core/veyron/profiles/roaming"
 	sflag "v.io/core/veyron/security/flag"
 
 	"v.io/apps/rps"
@@ -43,9 +43,10 @@
 	rand.Seed(time.Now().UnixNano())
 	rpsService := NewRPS(ctx)
 
-	ep, err := server.Listen(roaming.ListenSpec)
+	listenSpec := veyron2.GetListenSpec(ctx)
+	ep, err := server.Listen(listenSpec)
 	if err != nil {
-		vlog.Fatalf("Listen(%v) failed: %v", roaming.ListenSpec, err)
+		vlog.Fatalf("Listen(%v) failed: %v", listenSpec, err)
 	}
 	if *name == "" {
 		*name = common.CreateName()
diff --git a/rps/rpsplayer/main.go b/rps/rpsplayer/main.go
index ac0303f..59f4ea9 100644
--- a/rps/rpsplayer/main.go
+++ b/rps/rpsplayer/main.go
@@ -17,7 +17,7 @@
 	"v.io/core/veyron2/vlog"
 	"v.io/core/veyron2/vtrace"
 
-	"v.io/core/veyron/profiles/roaming"
+	_ "v.io/core/veyron/profiles/roaming"
 	sflag "v.io/core/veyron/security/flag"
 
 	"v.io/apps/rps"
@@ -109,9 +109,10 @@
 	}
 	ch := make(chan gameChallenge)
 
-	ep, err := server.Listen(roaming.ListenSpec)
+	listenSpec := veyron2.GetListenSpec(ctx)
+	ep, err := server.Listen(listenSpec)
 	if err != nil {
-		vlog.Fatalf("Listen(%v) failed: %v", roaming.ListenSpec, err)
+		vlog.Fatalf("Listen(%v) failed: %v", listenSpec, err)
 	}
 	if *name == "" {
 		*name = common.CreateName()
diff --git a/rps/rpsscorekeeper/main.go b/rps/rpsscorekeeper/main.go
index ff019c3..a6cd7c0 100644
--- a/rps/rpsscorekeeper/main.go
+++ b/rps/rpsscorekeeper/main.go
@@ -12,7 +12,7 @@
 	"v.io/core/veyron2/ipc"
 	"v.io/core/veyron2/vlog"
 
-	"v.io/core/veyron/profiles/roaming"
+	_ "v.io/core/veyron/profiles/roaming"
 	sflag "v.io/core/veyron/security/flag"
 
 	"v.io/apps/rps"
@@ -42,9 +42,10 @@
 	ch := make(chan rps.ScoreCard)
 	rpsService := &impl{ch}
 
-	ep, err := server.Listen(roaming.ListenSpec)
+	listenSpec := veyron2.GetListenSpec(ctx)
+	ep, err := server.Listen(listenSpec)
 	if err != nil {
-		vlog.Fatalf("Listen(%v) failed: %v", roaming.ListenSpec, err)
+		vlog.Fatalf("Listen(%v) failed: %v", listenSpec, err)
 	}
 	hostname, err := os.Hostname()
 	if err != nil {