service init --randomports:

Allow initialize cluster with random ports that are ununsed (at the moment of initialization)

cmd/ipfs-cluster-service/main.go

@@ -272,6 +272,10 @@ the peer IDs in the given multiaddresses.
 					Name:  "force, f",
 					Usage: "overwrite configuration without prompting",
 				},
+				cli.BoolFlag{
+					Name:  "randomports",
+					Usage: "configure random ports to listen on instead of defaults",
+				},
 			},
 			Action: func(c *cli.Context) error {
 				consensus := c.String("consensus")
@@ -319,6 +323,16 @@ the peer IDs in the given multiaddresses.
 				// Generate defaults for all registered components
 				err := cfgHelper.Manager().Default()
 				checkErr("generating default configuration", err)
+				if c.Bool("randomports") {
+					cfgs := cfgHelper.Configs()
+
+					cfgs.Cluster.ListenAddr, err = cmdutils.RandomizePorts(cfgs.Cluster.ListenAddr)
+					checkErr("randomizing ports", err)
+					cfgs.Restapi.HTTPListenAddr, err = cmdutils.RandomizePorts(cfgs.Restapi.HTTPListenAddr)
+					checkErr("randomizing ports", err)
+					cfgs.Ipfsproxy.ListenAddr, err = cmdutils.RandomizePorts(cfgs.Ipfsproxy.ListenAddr)
+					checkErr("randomizing ports", err)
+				}
 				err = cfgHelper.Manager().ApplyEnvVars()
 				checkErr("applying environment variables to configuration", err)
 

cmd/ipfs-cluster-service/main_test.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/ipfs/ipfs-cluster/cmdutils"
+
+	ma "github.com/multiformats/go-multiaddr"
+)
+
+func TestRandomPorts(t *testing.T) {
+	m1, _ := ma.NewMultiaddr("/ip4/0.0.0.0/tcp/9096")
+	m2, _ := ma.NewMultiaddr("/ip4/0.0.0.0/tcp/9096")
+
+	m1, err := cmdutils.RandomizePorts(m1)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	v1, err := m1.ValueForProtocol(ma.P_TCP)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	v2, err := m2.ValueForProtocol(ma.P_TCP)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if v1 == v2 {
+		t.Error("expected different ports")
+	}
+}

cmdutils/cmdutils.go

@@ -1,3 +1,58 @@
 // Package cmdutils contains utilities to facilitate building of command line
 // applications launching cluster peers.
 package cmdutils
+
+import (
+	"fmt"
+	"net"
+
+	ma "github.com/multiformats/go-multiaddr"
+)
+
+// RandomizePorts replaces TCP and UDP ports with random, but valid port
+// values.
+func RandomizePorts(m ma.Multiaddr) (ma.Multiaddr, error) {
+	var prev string
+
+	var err error
+	components := []ma.Multiaddr{}
+	ma.ForEach(m, func(c ma.Component) bool {
+		code := c.Protocol().Code
+
+		if code != ma.P_TCP && code != ma.P_UDP {
+			components = append(components, &c)
+			prev = c.Value()
+			return true
+		}
+
+		var ln net.Listener
+		ln, err = net.Listen(c.Protocol().Name, prev+":")
+		if err != nil {
+			return false
+		}
+		defer ln.Close()
+
+		var c1 *ma.Component
+		c1, err = ma.NewComponent(c.Protocol().Name, fmt.Sprintf("%d", getPort(ln, code)))
+		if err != nil {
+			return false
+		}
+
+		components = append(components, c1)
+		prev = c.Value()
+
+		return true
+	})
+
+	return ma.Join(components...), err
+}
+
+func getPort(ln net.Listener, code int) int {
+	if code == ma.P_TCP {
+		return ln.Addr().(*net.TCPAddr).Port
+	}
+	if code == ma.P_UDP {
+		return ln.Addr().(*net.UDPAddr).Port
+	}
+	return 0
+}