createCluster: fallback to default api port if random allocation fails

cmd/create/createCluster.go

@@ -110,7 +110,7 @@ func NewCmdCreateCluster() *cobra.Command {
 	/*********
 	 * Flags *
 	 *********/
-	cmd.Flags().StringP("api-port", "a", "", "Specify the Kubernetes API server port exposed on the LoadBalancer (Format: `--api-port [HOST:]HOSTPORT`)\n - Example: `k3d create -m 3 -a 0.0.0.0:6550`")
+	cmd.Flags().StringP("api-port", "a", "random", "Specify the Kubernetes API server port exposed on the LoadBalancer (Format: `--api-port [HOST:]HOSTPORT`)\n - Example: `k3d create -m 3 -a 0.0.0.0:6550`")
 	cmd.Flags().IntP("masters", "m", 1, "Specify how many masters you want to create")
 	cmd.Flags().IntP("workers", "w", 0, "Specify how many workers you want to create")
 	cmd.Flags().StringP("image", "i", fmt.Sprintf("%s:%s", k3d.DefaultK3sImageRepo, version.GetK3sVersion(false)), "Specify k3s image that you want to use for the nodes")

cmd/util/ports.go

@@ -54,15 +54,17 @@ func ParseAPIPort(portString string) (k3d.ExposeAPI, error) {
 	}
 
 	// Verify 'port' is an integer and within port ranges
-	if exposeAPI.Port == "" {
+	if exposeAPI.Port == "" || exposeAPI.Port == "random" {
 		log.Debugf("API-Port Mapping didn't specify hostPort, choosing one randomly...")
 		freePort, err := GetFreePort()
 		if err != nil || freePort == 0 {
-			log.Errorln("Failed to get a free port")
-			return exposeAPI, err
+			log.Warnf("Failed to get random free port:\n%+v", err)
+			log.Warnf("Falling back to default port %s (may be blocked though)...", k3d.DefaultAPIPort)
+			exposeAPI.Port = k3d.DefaultAPIPort
+		} else {
+			exposeAPI.Port = strconv.Itoa(freePort)
+			log.Debugf("Got free port for API: '%d'", freePort)
 		}
-		exposeAPI.Port = strconv.Itoa(freePort)
-		log.Debugf("Got free port for API: '%d'", freePort)
 	}
 	p, err := strconv.Atoi(exposeAPI.Port)
 	if err != nil {

tests/test_basic.sh

@@ -8,7 +8,7 @@ source "$CURR_DIR/common.sh"
 
 info "Creating two clusters..."
 $EXE create cluster c1 --wait --timeout 60s --api-port 6443 || failed "could not create cluster c1"
-$EXE create cluster c2 --wait --timeout 60s --api-port 6444 || failed "could not create cluster c2"
+$EXE create cluster c2 --wait --timeout 60s || failed "could not create cluster c2"
 
 info "Checking that we can get both clusters..."
 check_cluster_count 2