feature/appconnectors: start making it modular

Saves 45 KB.

Updates #12614

Change-Id: Iaeb73e69633878ce0a0f58c986024784bbe218f1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/ipnlocal/c2n.go

@@ -51,9 +51,6 @@ var c2nHandlers = map[methodAndPath]c2nHandler{
 	// SSH
 	req("/ssh/usernames"): handleC2NSSHUsernames,
 
-	// App Connectors.
-	req("GET /appconnector/routes"): handleC2NAppConnectorDomainRoutesGet,
-
 	// Linux netfilter.
 	req("POST /netfilter-kind"): handleC2NSetNetfilterKind,
 }
@@ -294,27 +291,6 @@ func handleC2NSockStats(b *LocalBackend, w http.ResponseWriter, r *http.Request)
 	fmt.Fprintf(w, "debug info: %v\n", sockstats.DebugInfo())
 }
 
-// handleC2NAppConnectorDomainRoutesGet handles returning the domains
-// that the app connector is responsible for, as well as the resolved
-// IP addresses for each domain. If the node is not configured as
-// an app connector, an empty map is returned.
-func handleC2NAppConnectorDomainRoutesGet(b *LocalBackend, w http.ResponseWriter, r *http.Request) {
-	b.logf("c2n: GET /appconnector/routes received")
-
-	var res tailcfg.C2NAppConnectorDomainRoutesResponse
-	appConnector := b.AppConnector()
-	if appConnector == nil {
-		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode(res)
-		return
-	}
-
-	res.Domains = appConnector.DomainRoutes()
-
-	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(res)
-}
-
 func handleC2NSetNetfilterKind(b *LocalBackend, w http.ResponseWriter, r *http.Request) {
 	b.logf("c2n: POST /netfilter-kind received")
 

ipn/ipnlocal/local.go

@@ -398,9 +398,10 @@ type LocalBackend struct {
 }
 
 // HealthTracker returns the health tracker for the backend.
-func (b *LocalBackend) HealthTracker() *health.Tracker {
-	return b.health
-}
+func (b *LocalBackend) HealthTracker() *health.Tracker { return b.health }
+
+// Logger returns the logger for the backend.
+func (b *LocalBackend) Logger() logger.Logf { return b.logf }
 
 // UserMetricsRegistry returns the usermetrics registry for the backend
 func (b *LocalBackend) UserMetricsRegistry() *usermetric.Registry {
@@ -4154,6 +4155,9 @@ func (b *LocalBackend) SetUseExitNodeEnabled(actor ipnauth.Actor, v bool) (ipn.P
 // MaybeClearAppConnector clears the routes from any AppConnector if
 // AdvertiseRoutes has been set in the MaskedPrefs.
 func (b *LocalBackend) MaybeClearAppConnector(mp *ipn.MaskedPrefs) error {
+	if !buildfeatures.HasAppConnectors {
+		return nil
+	}
 	var err error
 	if ac := b.AppConnector(); ac != nil && mp.AdvertiseRoutesSet {
 		err = ac.ClearRoutes()
@@ -4770,6 +4774,9 @@ func (b *LocalBackend) blockEngineUpdates(block bool) {
 // current network map and preferences.
 // b.mu must be held.
 func (b *LocalBackend) reconfigAppConnectorLocked(nm *netmap.NetworkMap, prefs ipn.PrefsView) {
+	if !buildfeatures.HasAppConnectors {
+		return
+	}
 	const appConnectorCapName = "tailscale.com/app-connectors"
 	defer func() {
 		if b.hostinfo != nil {
@@ -4943,7 +4950,9 @@ func (b *LocalBackend) authReconfig() {
 	b.logf("[v1] authReconfig: ra=%v dns=%v 0x%02x: %v", prefs.RouteAll(), prefs.CorpDNS(), flags, err)
 
 	b.initPeerAPIListener()
-	b.readvertiseAppConnectorRoutes()
+	if buildfeatures.HasAppConnectors {
+		b.readvertiseAppConnectorRoutes()
+	}
 }
 
 // shouldUseOneCGNATRoute reports whether we should prefer to make one big
@@ -6363,6 +6372,9 @@ func (b *LocalBackend) OfferingExitNode() bool {
 // OfferingAppConnector reports whether b is currently offering app
 // connector services.
 func (b *LocalBackend) OfferingAppConnector() bool {
+	if !buildfeatures.HasAppConnectors {
+		return false
+	}
 	b.mu.Lock()
 	defer b.mu.Unlock()
 	return b.appConnector != nil
@@ -6372,6 +6384,9 @@ func (b *LocalBackend) OfferingAppConnector() bool {
 //
 // TODO(nickkhyl): move app connectors to [nodeBackend], or perhaps a feature package?
 func (b *LocalBackend) AppConnector() *appc.AppConnector {
+	if !buildfeatures.HasAppConnectors {
+		return nil
+	}
 	b.mu.Lock()
 	defer b.mu.Unlock()
 	return b.appConnector
@@ -6917,6 +6932,9 @@ func (b *LocalBackend) DebugBreakDERPConns() error {
 // ObserveDNSResponse passes a DNS response from the PeerAPI DNS server to the
 // App Connector to enable route discovery.
 func (b *LocalBackend) ObserveDNSResponse(res []byte) error {
+	if !buildfeatures.HasAppConnectors {
+		return nil
+	}
 	var appConnector *appc.AppConnector
 	b.mu.Lock()
 	if b.appConnector == nil {
@@ -7020,6 +7038,9 @@ func namespaceKeyForCurrentProfile(pm *profileManager, key ipn.StateKey) ipn.Sta
 const routeInfoStateStoreKey ipn.StateKey = "_routeInfo"
 
 func (b *LocalBackend) storeRouteInfo(ri *appc.RouteInfo) error {
+	if !buildfeatures.HasAppConnectors {
+		return feature.ErrUnavailable
+	}
 	b.mu.Lock()
 	defer b.mu.Unlock()
 	if b.pm.CurrentProfile().ID() == "" {
@@ -7034,6 +7055,9 @@ func (b *LocalBackend) storeRouteInfo(ri *appc.RouteInfo) error {
 }
 
 func (b *LocalBackend) readRouteInfoLocked() (*appc.RouteInfo, error) {
+	if !buildfeatures.HasAppConnectors {
+		return nil, feature.ErrUnavailable
+	}
 	if b.pm.CurrentProfile().ID() == "" {
 		return &appc.RouteInfo{}, nil
 	}

ipn/ipnlocal/peerapi.go

@@ -745,7 +745,7 @@ func (h *peerAPIHandler) handleDNSQuery(w http.ResponseWriter, r *http.Request)
 	// TODO(raggi): consider pushing the integration down into the resolver
 	// instead to avoid re-parsing the DNS response for improved performance in
 	// the future.
-	if h.ps.b.OfferingAppConnector() {
+	if buildfeatures.HasAppConnectors && h.ps.b.OfferingAppConnector() {
 		if err := h.ps.b.ObserveDNSResponse(res); err != nil {
 			h.logf("ObserveDNSResponse error: %v", err)
 			// This is not fatal, we probably just failed to parse the upstream