split integration tests into multiple packages

This makes them complete more quickly (because they are run in parallel) and
invalidates only the cache for the integration test I’m working on, not for all
of them.

integration/dhcpv4/dhcpv4_test.go

@@ -46,7 +46,7 @@ func TestDHCPv4(t *testing.T) {
 	ready.Close()                 // dnsmasq will re-create the file anyway
 	defer os.Remove(ready.Name()) // dnsmasq does not clean up its pid file
 
-	dnsmasq := dnsmasq.Run(t, "veth0b")
+	dnsmasq := dnsmasq.Run(t, "veth0b", ns)
 	defer dnsmasq.Kill()
 
 	// f, err := os.Create("/tmp/pcap")

integration/dhcpv6/dhcpv6_test.go

@@ -16,7 +16,7 @@ import (
 var v6AddrRe = regexp.MustCompile(`2001:db8::[^ ]+`)
 
 func TestDHCPv6(t *testing.T) {
-	const ns = "ns0" // name of the network namespace to use for this test
+	const ns = "ns1" // name of the network namespace to use for this test
 
 	if err := exec.Command("ip", "netns", "add", ns).Run(); err != nil {
 		t.Fatalf("ip netns add %s: %v", ns, err)
@@ -45,7 +45,7 @@ func TestDHCPv6(t *testing.T) {
 		}
 	}
 
-	dnsmasq := dnsmasq.Run(t, "veth1b")
+	dnsmasq := dnsmasq.Run(t, "veth1b", ns)
 	defer dnsmasq.Kill()
 
 	// f, err := os.Create("/tmp/pcap6")

integration/radvd/radvd_test.go

@@ -10,7 +10,7 @@ import (
 )
 
 func TestRouterAdvertisement(t *testing.T) {
-	const ns = "ns0" // name of the network namespace to use for this test
+	const ns = "ns2" // name of the network namespace to use for this test
 
 	if err := exec.Command("ip", "netns", "add", ns).Run(); err != nil {
 		t.Fatalf("ip netns add %s: %v", ns, err)
@@ -18,20 +18,20 @@ func TestRouterAdvertisement(t *testing.T) {
 	defer exec.Command("ip", "netns", "delete", ns).Run()
 
 	nsSetup := []*exec.Cmd{
-		exec.Command("ip", "link", "add", "veth0a", "type", "veth", "peer", "name", "veth0b", "netns", ns),
+		exec.Command("ip", "link", "add", "veth2a", "type", "veth", "peer", "name", "veth2b", "netns", ns),
 
 		// Disable Duplicate Address Detection: until DAD completes, the link-local
 		// address remains in state “tentative”, resulting in any attempts to
 		// bind(2) to the address to fail with -EADDRNOTAVAIL.
-		exec.Command("/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth0a/accept_dad"),
+		exec.Command("/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth2a/accept_dad"),
-		exec.Command("ip", "netns", "exec", ns, "/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth0b/accept_dad"),
+		exec.Command("ip", "netns", "exec", ns, "/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth2b/accept_dad"),
 
-		exec.Command("ip", "link", "set", "veth0a", "up"),
+		exec.Command("ip", "link", "set", "veth2a", "up"),
-		exec.Command("ip", "netns", "exec", ns, "ip", "addr", "add", "192.168.23.1/24", "dev", "veth0b"),
+		exec.Command("ip", "netns", "exec", ns, "ip", "addr", "add", "192.168.23.1/24", "dev", "veth2b"),
-		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth0b", "up"),
+		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth2b", "up"),
-		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth0b"),
+		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth2b"),
 
-		exec.Command("/bin/sh", "-c", "echo 1 > /proc/sys/net/ipv6/conf/veth0a/forwarding"),
+		exec.Command("/bin/sh", "-c", "echo 1 > /proc/sys/net/ipv6/conf/veth2a/forwarding"),
 	}
 
 	for _, cmd := range nsSetup {
@@ -59,7 +59,7 @@ func TestRouterAdvertisement(t *testing.T) {
 		t.Fatal(err)
 	}
 	go func() {
-		if err := srv.Serve("veth0a", conn); err != nil {
+		if err := srv.Serve("veth2a", conn); err != nil {
 			t.Fatal(err)
 		}
 	}()
@@ -68,7 +68,7 @@ func TestRouterAdvertisement(t *testing.T) {
 		"--single",     // exit after first router advertisement
 		"--retry", "1", // retry only once
 		"--wait", "1000", // wait 1s
-		"veth0b")
+		"veth2b")
 	rdisc6.Stderr = os.Stderr
 	b, err := rdisc6.Output()
 	if err != nil {

internal/testing/dnsmasq/dnsmasq.go

@@ -30,9 +30,7 @@ type Process struct {
 var dhcpActionRe = regexp.MustCompile(` (DHCP[^(]+\(.*)$`)
 
 // Run starts a dnsmasq(8) process and returns a handle to it.
-func Run(t *testing.T, iface string) *Process {
+func Run(t *testing.T, iface, ns string) *Process {
-	const ns = "ns0" // TODO: configurable?
-
 	ready, err := ioutil.TempFile("", "router7")
 	if err != nil {
 		t.Fatal(err)

internal/testing/dnsmasq/example_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func Example(t *testing.T) {
-	dnsmasq := dnsmasq.Run(t, "veth0b")
+	dnsmasq := dnsmasq.Run(t, "veth0b", "ns0")
 	defer dnsmasq.Kill()
 	// test code here