feat(satellite): advertise reachable endpoint to controller via Hello

HelloRequest gains satellite_endpoint; the satellite passes its
$POD_IP:7000 (or whatever --advertised-endpoint says). The controller
persists it as a Node prop so future ApplyResources dispatch can dial
the satellite back.

DaemonSet now exposes containerPort 7000 and pipes spec.nodeName /
status.podIP into NODE_NAME / POD_IP env vars; --listen :7000 brings
up the satellite-side gRPC server.

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Andrei Kvapil <kvapss@gmail.com>

Author: kvaps

cmd/satellite/main.go

@@ -64,6 +64,14 @@ func run() int {
 		"directory the satellite uses to persist DRBD .res files and per-resource state")
 	flag.StringVar(&listenAddr, "listen", ":7000",
 		"bind address for the satellite-side gRPC server (controller dials this for ApplyResources)")
+
+	advertised := os.Getenv("POD_IP")
+	if advertised != "" {
+		advertised += ":7000"
+	}
+
+	flag.StringVar(&advertised, "advertised-endpoint", advertised,
+		"host:port the controller should dial back at (defaults to $POD_IP:7000)")
 	flag.StringVar(&lvmPoolName, "lvm-pool-name", "",
 		"register an LVM-thin pool under this LINSTOR pool name (empty disables LVM)")
 	flag.StringVar(&lvmVG, "lvm-vg", "",
@@ -99,13 +107,14 @@ func run() int {
 	}
 
 	agent := satellite.NewAgent(satellite.Config{
-		NodeName:       nodeName,
-		ControllerAddr: controllerAddr,
-		ListenAddr:     listenAddr,
-		StateDir:       stateDir,
-		Providers:      providers,
-		DialTimeout:    10 * time.Second,
-		Logger:         logger,
+		NodeName:           nodeName,
+		ControllerAddr:     controllerAddr,
+		ListenAddr:         listenAddr,
+		AdvertisedEndpoint: advertised,
+		StateDir:           stateDir,
+		Providers:          providers,
+		DialTimeout:        10 * time.Second,
+		Logger:             logger,
 	})
 
 	providerNames := make([]string, 0, len(providers))

pkg/satellite/agent.go

@@ -53,6 +53,12 @@ type Config struct {
 	// RPCs, ship). Empty disables the server (useful for unit tests).
 	ListenAddr string
 
+	// AdvertisedEndpoint is the host:port the satellite tells the
+	// controller to dial back at. Differs from ListenAddr when the
+	// satellite binds to 0.0.0.0:7000 but is reachable from the
+	// controller as <pod-ip>:7000.
+	AdvertisedEndpoint string
+
 	// StateDir is the on-disk directory the satellite uses for DRBD .res
 	// files and per-resource state. Required.
 	StateDir string
@@ -209,10 +215,11 @@ func (a *Agent) hello(ctx context.Context, client satellitepb.ControllerClient)
 	defer cancel()
 
 	resp, err := client.Hello(rpcCtx, &satellitepb.HelloRequest{
-		NodeName:         a.cfg.NodeName,
-		BlockstorVersion: version.Version,
-		LayerKinds:       []string{"DRBD", "STORAGE", "LUKS"},
-		ProviderKinds:    []string{"LVM", "LVM_THIN", "ZFS", "ZFS_THIN", "FILE"},
+		NodeName:          a.cfg.NodeName,
+		BlockstorVersion:  version.Version,
+		LayerKinds:        []string{"DRBD", "STORAGE", "LUKS"},
+		ProviderKinds:     []string{"LVM", "LVM_THIN", "ZFS", "ZFS_THIN", "FILE"},
+		SatelliteEndpoint: a.cfg.AdvertisedEndpoint,
 	})
 	if err != nil {
 		return errors.Wrap(err, "Hello RPC")