tstest/integration/vms: print qemu console output, fix printing issues

Fix a few test printing issues when tests fail.

Qemu console output is super useful when something is wrong in the
harness and we cannot even bring up the tests.
Also useful for figuring out where all the time goes in tests.

A little noisy, but not too noisy as long as you're only running one VM
as part of the tests, which is my plan.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>

tstest/integration/vms/vms_test.go

@@ -30,7 +30,6 @@ import (
 	"golang.org/x/sync/semaphore"
 	"inet.af/netaddr"
 	"tailscale.com/tstest"
-	"tailscale.com/tstest/integration"
 	"tailscale.com/types/logger"
 )
 
@@ -45,6 +44,7 @@ var (
 	vmRamLimit        = flag.Int("ram-limit", 4096, "the maximum number of megabytes of ram that can be used for VMs, must be greater than or equal to 1024")
 	useVNC            = flag.Bool("use-vnc", false, "if set, display guest vms over VNC")
 	verboseLogcatcher = flag.Bool("verbose-logcatcher", false, "if set, spew logcatcher to t.Logf (spamtastic)")
+	verboseQemu       = flag.Bool("verbose-qemu", true, "if set, print qemu console to t.Logf")
 	distroRex         = func() *regexValue {
 		result := &regexValue{r: regexp.MustCompile(`.*`)}
 		flag.Var(result, "distro-regex", "The regex that matches what distros should be run")
@@ -57,22 +57,18 @@ func TestDownloadImages(t *testing.T) {
 		t.Skip("not running integration tests (need --run-vm-tests)")
 	}
 
-	bins := integration.BuildTestBinaries(t)
-
 	for _, d := range Distros {
 		distro := d
 		t.Run(distro.Name, func(t *testing.T) {
+			t.Parallel()
 			if !distroRex.Unwrap().MatchString(distro.Name) {
 				t.Skipf("distro name %q doesn't match regex: %s", distro.Name, distroRex)
 			}
-
 			if strings.HasPrefix(distro.Name, "nixos") {
 				t.Skip("NixOS is built on the fly, no need to download it")
 			}
 
-			t.Parallel()
-
-			(&Harness{bins: bins}).fetchDistro(t, distro)
+			fetchDistro(t, distro)
 		})
 	}
 }
@@ -270,23 +266,36 @@ func testOneDistribution(t *testing.T, n int, distro Distro) {
 	}
 	t.Cleanup(func() { ramsem.sem.Release(int64(distro.MemoryMegs)) })
 
-	h.mkVM(t, n, distro, h.pubKey, h.loginServerURL, dir)
+	vm := h.mkVM(t, n, distro, h.pubKey, h.loginServerURL, dir)
 	var ipm ipMapping
 
-	t.Run("wait-for-start", func(t *testing.T) {
-		waiter := time.NewTicker(time.Second)
-		defer waiter.Stop()
-		var ok bool
-		for {
-			<-waiter.C
-			h.ipMu.Lock()
-			if ipm, ok = h.ipMap[distro.Name]; ok {
-				h.ipMu.Unlock()
-				break
-			}
-			h.ipMu.Unlock()
+	for i := 0; i < 100; i++ {
+		if vm.running() {
+			break
 		}
-	})
+		time.Sleep(100 * time.Millisecond)
+	}
+	if !vm.running() {
+		t.Fatal("vm not running")
+	}
+
+	waiter := time.NewTicker(time.Second)
+	defer waiter.Stop()
+	for {
+		var ok bool
+
+		h.ipMu.Lock()
+		ipm, ok = h.ipMap[distro.Name]
+		h.ipMu.Unlock()
+
+		if ok {
+			break
+		}
+		if !vm.running() {
+			t.Fatal("vm not running")
+		}
+		<-waiter.C
+	}
 
 	h.testDistro(t, distro, ipm)
 }
@@ -377,11 +386,10 @@ func (h *Harness) testDistro(t *testing.T, d Distro, ipm ipMapping) {
 
 			outp, err = sess.CombinedOutput("tailscale status")
 			if err == nil {
+				t.Logf("tailscale status: %s", outp)
 				if !strings.Contains(string(outp), "100.64.0.1") {
-					t.Log(string(outp))
 					t.Fatal("can't find tester IP")
 				}
-
 				return
 			}
 			time.Sleep(dur)