Adopt the predecessor's tunnel in place: its range, its address, its peers

On an adopted hub the private network takes over the tunnel it finds rather than running beside it (hq ADR 0105): two tunnels leave the mesh's unreachable through the provider's filter, so no machine can ever join. The node presents the found tunnel when it enrols, under the key it took as its own; the inventory records it (node.tunnel, tunnel_peer — migration 0031) and the mesh composes from it: the overlay's range is the adopted tunnel's, the hub is placed at the tunnel's address on the tunnel's port, and every peer the tunnel had is carried in the hub's peer list as a peer of the tunnel, not a node of the mesh, until a node enrols with that key — which then keeps the address the tunnel had for it. A fresh node never gets an address the tunnel holds. The hub's declaration tells the host which unit to take over; the host's account of carrying it is recorded and shown. Every reader of the range follows the setting; nothing stores it. A found tunnel under another key is recorded and not adopted, so ADR 0100's non-overlap rule keeps applying where a tunnel is left running beside the mesh's. A lab bed and test skeleton for "How it is checked" are under lab/.
2026-09-23 23:26:34 +02:00
parent 8fb32d7ee0
commit 3c836f0abb
16 changed files with 1351 additions and 42 deletions
@@ -108,3 +108,84 @@ func TestOnlyAMachineOnThePrivateNetworkIsNamed(t *testing.T) {
 		t.Fatalf("a machine that left the network is still named, or the one that stayed is not: %v", names)
 	}
 }
+
+// novox/hq ADR 0105: the range every address is composed from is the adopted tunnel's, read from
+// the tunnel the hub holds — never stored anywhere else.
+func TestTheOverlaysRangeIsTheAdoptedTunnels(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	t.Setenv(OverlayCIDRVar, "10.99.0.0/16")
+
+	before, err := overlayRange(ctx, inv)
+	if err != nil || before != "10.99.0.0/16" {
+		t.Fatalf("without an adopted tunnel the range is not what genesis said: %q %v", before, err)
+	}
+
+	// The hub becomes what genesis makes of a machine in use: adopted, enrolled with the found
+	// tunnel's key, and presenting the tunnel.
+	if err := inv.SetAdopted(ctx, "anchor", true); err != nil {
+		t.Fatal(err)
+	}
+	hub, err := inv.NodeByName(ctx, "anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	const key = "THE-TUNNELS-KEY========================="
+	if err := inv.RecordOverlayKey(ctx, hub.ID, key); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RecordTunnel(ctx, hub.ID, inventory.Tunnel{
+		Interface: "wg0", Unit: "wg-quick@wg0", Config: "/etc/wireguard/wg0.conf", Port: 51900,
+		Address: "192.0.2.1/24", Range: "192.0.2.0/24", PublicKey: key,
+		Peers: []inventory.TunnelPeer{{PublicKey: "PEER-TWO", Address: "192.0.2.2"}},
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	after, err := overlayRange(ctx, inv)
+	if err != nil || after != "192.0.2.0/24" {
+		t.Fatalf("with an adopted tunnel the range is %q (%v), not the tunnel's", after, err)
+	}
+
+	// A placement whose endpoint is on another port than the tunnel's is refused: the peers dial
+	// the tunnel's port.
+	err = overlayPlace(ctx, inv, []string{"anchor", "--endpoint", "198.51.100.10:51820", "--site", "hosting", "--hub"})
+	if err == nil || !strings.Contains(err.Error(), "51900") {
+		t.Fatalf("an endpoint off the tunnel's port was accepted: %v", err)
+	}
+	// On the tunnel's port, the hub is placed at the tunnel's address — whatever it had before.
+	if err := inv.SetPlace(ctx, "anchor", "", "", false, ""); err != nil {
+		t.Fatal(err)
+	}
+	if err := overlayPlace(ctx, inv, []string{"anchor", "--endpoint", "198.51.100.10:51900", "--site", "hosting", "--hub"}); err != nil {
+		t.Fatal(err)
+	}
+	if placed := placementOf(t, ctx, inv, "anchor"); placed.Address != "192.0.2.1" {
+		t.Fatalf("the hub was placed at %s, not the tunnel's own address", placed.Address)
+	}
+
+	// And the hub's declaration carries the peer and the takeover.
+	nodes, computed, err := graph(ctx, open)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var hubNode overlay.Node
+	for _, n := range nodes {
+		if n.Name == "anchor" {
+			hubNode = n
+		}
+	}
+	if hubNode.TakesOver == nil || hubNode.TakesOver.Unit != "wg-quick@wg0" {
+		t.Errorf("the hub is not told to take over the found tunnel: %+v", hubNode)
+	}
+	carried := false
+	for _, p := range computed["anchor"] {
+		if p.Key == "PEER-TWO" && p.Allowed == "192.0.2.2/32" {
+			carried = true
+		}
+	}
+	if !carried {
+		t.Errorf("the hub's peer list does not carry the tunnel's peer: %+v", computed["anchor"])
+	}
+}