ipn: add watch opt to include actions in health messages

Updates tailscale/corp#27759

Signed-off-by: James Sanderson <jsanderson@tailscale.com>

ipn/backend.go

@@ -81,6 +81,8 @@ const (
 	NotifyInitialHealthState NotifyWatchOpt = 1 << 7 // if set, the first Notify message (sent immediately) will contain the current health.State of the client
 
 	NotifyRateLimit NotifyWatchOpt = 1 << 8 // if set, rate limit spammy netmap updates to every few seconds
+
+	NotifyHealthActions NotifyWatchOpt = 1 << 9 // if set, include PrimaryActions in health.State. Otherwise append the action URL to the text
 )
 
 // Notify is a communication from a backend (e.g. tailscaled) to a frontend

ipn/ipnlocal/local.go

@@ -2948,28 +2948,19 @@ func (b *LocalBackend) WatchNotifications(ctx context.Context, mask ipn.NotifyWa
 	b.WatchNotificationsAs(ctx, nil, mask, onWatchAdded, fn)
 }
 
-// WatchNotificationsAs is like WatchNotifications but takes an [ipnauth.Actor]
+// WatchNotificationsAs is like [LocalBackend.WatchNotifications] but takes an [ipnauth.Actor]
 // as an additional parameter. If non-nil, the specified callback is invoked
 // only for notifications relevant to this actor.
 func (b *LocalBackend) WatchNotificationsAs(ctx context.Context, actor ipnauth.Actor, mask ipn.NotifyWatchOpt, onWatchAdded func(), fn func(roNotify *ipn.Notify) (keepGoing bool)) {
 	ch := make(chan *ipn.Notify, 128)
 	sessionID := rands.HexString(16)
-	origFn := fn
 	if mask&ipn.NotifyNoPrivateKeys != 0 {
-		fn = func(n *ipn.Notify) bool {
-			if n.NetMap == nil || n.NetMap.PrivateKey.IsZero() {
-				return origFn(n)
-			}
-
-			// The netmap in n is shared across all watchers, so to mutate it for a
-			// single watcher we have to clone the notify and the netmap. We can
-			// make shallow clones, at least.
-			nm2 := *n.NetMap
-			n2 := *n
-			n2.NetMap = &nm2
-			n2.NetMap.PrivateKey = key.NodePrivate{}
-			return origFn(&n2)
-		}
+		fn = filterPrivateKeys(fn)
+	}
+	if mask&ipn.NotifyHealthActions == 0 {
+		// if UI does not support PrimaryAction in health warnings, append
+		// action URLs to the warning text instead.
+		fn = appendHealthActions(fn)
 	}
 
 	var ini *ipn.Notify
@@ -3060,6 +3051,53 @@ func (b *LocalBackend) WatchNotificationsAs(ctx context.Context, actor ipnauth.A
 	sender.Run(ctx, ch)
 }
 
+// filterPrivateKeys returns an IPN listener func that wraps the supplied IPN
+// listener and zeroes out the PrivateKey in the NetMap passed to the wrapped
+// listener.
+func filterPrivateKeys(fn func(roNotify *ipn.Notify) (keepGoing bool)) func(*ipn.Notify) bool {
+	return func(n *ipn.Notify) bool {
+		if n.NetMap == nil || n.NetMap.PrivateKey.IsZero() {
+			return fn(n)
+		}
+
+		// The netmap in n is shared across all watchers, so to mutate it for a
+		// single watcher we have to clone the notify and the netmap. We can
+		// make shallow clones, at least.
+		nm2 := *n.NetMap
+		n2 := *n
+		n2.NetMap = &nm2
+		n2.NetMap.PrivateKey = key.NodePrivate{}
+		return fn(&n2)
+	}
+}
+
+// appendHealthActions returns an IPN listener func that wraps the supplied IPN
+// listener func and transforms health messages passed to the wrapped listener.
+// If health messages with PrimaryActions are present, it appends the label &
+// url in the PrimaryAction to the text of the message. For use for clients that
+// do not process the PrimaryAction.
+func appendHealthActions(fn func(roNotify *ipn.Notify) (keepGoing bool)) func(*ipn.Notify) bool {
+	return func(n *ipn.Notify) bool {
+		if n.Health == nil || len(n.Health.Warnings) == 0 {
+			return fn(n)
+		}
+
+		// Shallow clone the notify and health so we can mutate them
+		h2 := *n.Health
+		n2 := *n
+		n2.Health = &h2
+		n2.Health.Warnings = make(map[health.WarnableCode]health.UnhealthyState, len(n.Health.Warnings))
+		for k, v := range n.Health.Warnings {
+			if v.PrimaryAction != nil {
+				v.Text = fmt.Sprintf("%s %s: %s", v.Text, v.PrimaryAction.Label, v.PrimaryAction.URL)
+				v.PrimaryAction = nil
+			}
+			n2.Health.Warnings[k] = v
+		}
+		return fn(&n2)
+	}
+}
+
 // pollRequestEngineStatus calls b.e.RequestStatus every 2 seconds until ctx
 // is done.
 func (b *LocalBackend) pollRequestEngineStatus(ctx context.Context) {

ipn/ipnlocal/local_test.go

@@ -5348,6 +5348,8 @@ func TestDisplayMessages(t *testing.T) {
 	ht.SetIPNState("NeedsLogin", true)
 	ht.GotStreamedMapResponse()
 
+	b.mu.Lock()
+	defer b.mu.Unlock()
 	b.setNetMapLocked(&netmap.NetworkMap{
 		DisplayMessages: map[tailcfg.DisplayMessageID]tailcfg.DisplayMessage{
 			"test-message": {
@@ -5374,7 +5376,8 @@ func TestDisplayMessagesURLFilter(t *testing.T) {
 	ht.SetIPNState("NeedsLogin", true)
 	ht.GotStreamedMapResponse()
 
-	defer b.lockAndGetUnlock()()
+	b.mu.Lock()
+	defer b.mu.Unlock()
 	b.setNetMapLocked(&netmap.NetworkMap{
 		DisplayMessages: map[tailcfg.DisplayMessageID]tailcfg.DisplayMessage{
 			"test-message": {
@@ -5405,3 +5408,104 @@ func TestDisplayMessagesURLFilter(t *testing.T) {
 		t.Errorf("Unexpected message content (-want/+got):\n%s", diff)
 	}
 }
+
+// TestDisplayMessageIPNBus checks that we send health messages appropriately
+// based on whether the watcher has sent the [ipn.NotifyHealthActions] watch
+// option or not.
+func TestDisplayMessageIPNBus(t *testing.T) {
+	type test struct {
+		name        string
+		mask        ipn.NotifyWatchOpt
+		wantWarning health.UnhealthyState
+	}
+
+	msgs := map[tailcfg.DisplayMessageID]tailcfg.DisplayMessage{
+		"test-message": {
+			Title:    "Message title",
+			Text:     "Message text.",
+			Severity: tailcfg.SeverityMedium,
+			PrimaryAction: &tailcfg.DisplayMessageAction{
+				URL:   "https://example.com",
+				Label: "Learn more",
+			},
+		},
+	}
+
+	for _, tt := range []test{
+		{
+			name: "older-client-no-actions",
+			mask: 0,
+			wantWarning: health.UnhealthyState{
+				WarnableCode:  "test-message",
+				Severity:      health.SeverityMedium,
+				Title:         "Message title",
+				Text:          "Message text. Learn more: https://example.com", // PrimaryAction appended to text
+				PrimaryAction: nil,                                             // PrimaryAction not included
+			},
+		},
+		{
+			name: "new-client-with-actions",
+			mask: ipn.NotifyHealthActions,
+			wantWarning: health.UnhealthyState{
+				WarnableCode: "test-message",
+				Severity:     health.SeverityMedium,
+				Title:        "Message title",
+				Text:         "Message text.",
+				PrimaryAction: &health.UnhealthyStateAction{
+					URL:   "https://example.com",
+					Label: "Learn more",
+				},
+			},
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			lb := newLocalBackendWithTestControl(t, false, func(tb testing.TB, opts controlclient.Options) controlclient.Client {
+				return newClient(tb, opts)
+			})
+
+			ipnWatcher := newNotificationWatcher(t, lb, nil)
+			ipnWatcher.watch(tt.mask, []wantedNotification{{
+				name: "test",
+				cond: func(_ testing.TB, _ ipnauth.Actor, n *ipn.Notify) bool {
+					if n.Health == nil {
+						return false
+					}
+					got, ok := n.Health.Warnings["test-message"]
+					if ok {
+						if diff := cmp.Diff(tt.wantWarning, got); diff != "" {
+							t.Errorf("unexpected warning details (-want/+got):\n%s", diff)
+							return true // we failed the test so tell the watcher we've seen what we need to to stop it waiting
+						}
+					}
+					return ok
+				},
+			}})
+
+			lb.SetPrefsForTest(&ipn.Prefs{
+				ControlURL:  "https://localhost:1/",
+				WantRunning: true,
+				LoggedOut:   false,
+			})
+			if err := lb.Start(ipn.Options{}); err != nil {
+				t.Fatalf("(*LocalBackend).Start(): %v", err)
+			}
+
+			cc := lb.cc.(*mockControl)
+
+			// Assert that we are logged in and authorized, and also send our DisplayMessages
+			cc.send(nil, "", true, &netmap.NetworkMap{
+				SelfNode:        (&tailcfg.Node{MachineAuthorized: true}).View(),
+				DisplayMessages: msgs,
+			})
+
+			// Tell the health tracker that we are in a map poll because
+			// mockControl doesn't tell it
+			lb.HealthTracker().GotStreamedMapResponse()
+
+			// Assert that we got the expected notification
+			ipnWatcher.check()
+		})
+	}
+}