ipn/ipnlocal: populate peers' capabilities

Populates capabilties field of peers in ipn status.
Updates tailscale/corp#17516

ipn/ipnlocal/local.go

@@ -877,6 +877,7 @@ func (b *LocalBackend) populatePeerStatusLocked(sb *ipnstate.StatusBuilder) {
 			ExitNode:        p.StableID() != "" && p.StableID() == exitNodeID,
 			SSH_HostKeys:    p.Hostinfo().SSH_HostKeys().AsSlice(),
 			Location:        p.Hostinfo().Location(),
+			Capabilities:    p.Capabilities().AsSlice(),
 		}
 		peerStatusFromNode(ps, p)
 

ipn/ipnlocal/local_test.go

@@ -729,6 +729,55 @@ func TestStatusWithoutPeers(t *testing.T) {
 	}
 }
 
+func TestStatusPeerCapabilities(t *testing.T) {
+	b := newTestLocalBackend(t)
+
+	var cc *mockControl
+	b.SetControlClientGetterForTesting(func(opts controlclient.Options) (controlclient.Client, error) {
+		cc = newClient(t, opts)
+
+		t.Logf("ccGen: new mockControl.")
+		cc.called("New")
+		return cc, nil
+	})
+	b.Start(ipn.Options{})
+	b.Login(nil)
+	cc.send(nil, "", false, &netmap.NetworkMap{
+		SelfNode: (&tailcfg.Node{
+			MachineAuthorized: true,
+			Addresses:         ipps("100.101.101.101"),
+		}).View(),
+		Peers: []tailcfg.NodeView{
+			(&tailcfg.Node{
+				ID:              1,
+				StableID:        "foo",
+				IsWireGuardOnly: true,
+				Hostinfo:        (&tailcfg.Hostinfo{}).View(),
+				Capabilities:    []tailcfg.NodeCapability{tailcfg.CapabilitySSH},
+			}).View(),
+			(&tailcfg.Node{
+				ID:           2,
+				StableID:     "bar",
+				Hostinfo:     (&tailcfg.Hostinfo{}).View(),
+				Capabilities: []tailcfg.NodeCapability{tailcfg.CapabilitySSH},
+			}).View(),
+		},
+	})
+	got := b.Status()
+	if got.TailscaleIPs == nil {
+		t.Errorf("got nil, expected TailscaleIPs value to not be nil")
+	}
+	if !reflect.DeepEqual(got.TailscaleIPs, got.Self.TailscaleIPs) {
+		t.Errorf("got %v, expected %v", got.TailscaleIPs, got.Self.TailscaleIPs)
+	}
+
+	for _, peer := range got.Peer {
+		if peer.Capabilities == nil {
+			t.Errorf("expected populated capabilities field")
+		}
+	}
+}
+
 // legacyBackend was the interface between Tailscale frontends
 // (e.g. cmd/tailscale, iOS/MacOS/Windows GUIs) and the tailscale
 // backend (e.g. cmd/tailscaled) running on the same machine.