feat(rest): stub /v1/node-connections endpoints

linstor-csi polls the inter-satellite connection matrix every status
cycle. Cozystack clusters run flat L2 with no node-to-node tunnels to
configure, so we return an empty list — the canonical "all healthy"
answer per the upstream contract. Without the stub, every poll logs
404 noise.

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

Author: kvaps

pkg/rest/node_connections.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2026 Cozystack contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package rest
+
+import (
+	"net/http"
+)
+
+// registerNodeConnections wires `GET /v1/node-connections`. Java LINSTOR
+// returns the inter-satellite connection matrix here; cozystack runs flat
+// L2, so we report none and let golinstor's reconciler treat that as the
+// healthy default. Without this stub the call 404s and linstor-csi's
+// status polls log an error every cycle.
+func (s *Server) registerNodeConnections(mux *http.ServeMux) {
+	mux.HandleFunc("GET /v1/node-connections", handleEmptyArray)
+	mux.HandleFunc("GET /v1/node-connections/{src}/{dst}", handleEmptyArray)
+}
+
+// handleEmptyArray writes a JSON `[]` body — the canonical empty-list
+// answer that golinstor decodes into a zero-element slice.
+func handleEmptyArray(w http.ResponseWriter, _ *http.Request) {
+	writeJSON(w, http.StatusOK, []struct{}{})
+}

pkg/rest/server.go

@@ -120,6 +120,7 @@ func (s *Server) buildMux() *http.ServeMux {
 	s.registerRDClone(mux)
 	s.registerSOSReport(mux)
 	s.registerRemotes(mux)
+	s.registerNodeConnections(mux)
 
 	return mux
 }