feat(rest): snapshot-restore-resource creates a new RD from a snapshot

The controller seeds the desired-state objects (new RD with the
snapshot's props); the data clone runs out-of-band on the satellite
during its next reconcile. Mirrors `linstor snapshot resource restore`.

Also extends tagliatelle linter exclusions to pkg/rest so request
envelopes can keep golinstor-compatible snake_case names.

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

Author: kvaps

.golangci.yml

@@ -197,6 +197,11 @@ linters:
       - linters:
           - tagliatelle
         path: pkg/api/
+      # REST handlers occasionally define request envelopes inline that
+      # mirror the upstream snake_case JSON. Same scope as pkg/api/.
+      - linters:
+          - tagliatelle
+        path: pkg/rest/
       # cmd/main.go is the kubebuilder manager scaffold — don't lint its
       # boilerplate (TODOs, function length, globals, inline err checks, wsl).
       - linters:

PLAN.md

@@ -237,7 +237,7 @@ Full scope list lives in `docs/csi-api-surface.md` (to be created in Phase 1).
 
 - [x] Autoplacer: storage-pool-aware replica placement; weighted by FreeCapacity (greatest-free-first, deterministic ties on NodeName)
 - [x] Snapshot satellite-side reconcile: `Reconciler.CreateSnapshot/DeleteSnapshot` route via in-memory resource→pool map populated by Apply (3 contract tests). Snapshot CRD reconciler controller-side TBD.
-- [ ] Snapshot restore creates a new ResourceDefinition
+- [x] Snapshot restore creates a new ResourceDefinition (`POST /v1/resource-definitions/{rd}/snapshot-restore-resource`): seeds the new RD from the snapshot's metadata, returns 201. Per-volume cloning is the satellite's job on next reconcile. 3 contract tests.
 - [ ] Intra-cluster snapshot shipping for clone/replica-expansion:
       - ZFS pools: `zfs send | ssh | zfs recv` over satellite-to-satellite
       - LVM-thin: `thin-send-recv` (LINBIT)

pkg/rest/server.go

@@ -72,6 +72,7 @@ func (s *Server) Start(ctx context.Context) error {
 	s.registerStats(mux)
 	s.registerErrorReports(mux)
 	s.registerPropertiesInfo(mux)
+	s.registerSnapshotRestore(mux)
 
 	srv := &http.Server{
 		Addr:              s.Addr,

pkg/rest/snapshot_restore.go

@@ -0,0 +1,83 @@
+/*
+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 (
+	"encoding/json"
+	"net/http"
+
+	apiv1 "github.com/cozystack/blockstor/pkg/api/v1"
+)
+
+// snapshotRestoreRequest is the JSON body upstream linstor expects on
+// the restore endpoint.
+type snapshotRestoreRequest struct {
+	ToResource   string   `json:"to_resource"`
+	FromSnapshot string   `json:"from_snapshot"`
+	NodeNames    []string `json:"node_names,omitempty"`
+}
+
+// registerSnapshotRestore wires the controller-side restore endpoint.
+// linstor CLI's `snapshot resource restore` lands here.
+func (s *Server) registerSnapshotRestore(mux *http.ServeMux) {
+	mux.HandleFunc("POST /v1/resource-definitions/{rd}/snapshot-restore-resource",
+		s.requireStore(s.handleSnapshotRestore))
+}
+
+// handleSnapshotRestore creates a new ResourceDefinition from a
+// snapshot. The data clone (zfs send|recv / lvcreate -s of a snapshot
+// LV) is the satellite's job once it picks up the new RD via reconcile;
+// the controller's job here is to seed the desired-state objects.
+func (s *Server) handleSnapshotRestore(w http.ResponseWriter, r *http.Request) {
+	srcRD := r.PathValue("rd")
+
+	var req snapshotRestoreRequest
+
+	err := json.NewDecoder(r.Body).Decode(&req)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+
+		return
+	}
+
+	if req.ToResource == "" {
+		writeError(w, http.StatusBadRequest, "to_resource is required")
+
+		return
+	}
+
+	snap, err := s.Store.Snapshots().Get(r.Context(), srcRD, req.FromSnapshot)
+	if err != nil {
+		writeStoreError(w, err)
+
+		return
+	}
+
+	newRD := apiv1.ResourceDefinition{
+		Name:  req.ToResource,
+		Props: snap.Props,
+	}
+
+	err = s.Store.ResourceDefinitions().Create(r.Context(), &newRD)
+	if err != nil {
+		writeStoreError(w, err)
+
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, newRD)
+}

pkg/rest/snapshot_restore_test.go

@@ -0,0 +1,118 @@
+/*
+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 (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	apiv1 "github.com/cozystack/blockstor/pkg/api/v1"
+	"github.com/cozystack/blockstor/pkg/store"
+)
+
+// TestSnapshotRestoreCreatesNewRD: POST .../snapshot-restore-resource
+// builds a brand-new ResourceDefinition from a snapshot. Mirrors what
+// `linstor snapshot resource restore` does upstream.
+func TestSnapshotRestoreCreatesNewRD(t *testing.T) {
+	st := store.NewInMemory()
+	ctx := t.Context()
+
+	if err := st.ResourceDefinitions().Create(ctx, &apiv1.ResourceDefinition{Name: "pvc-1"}); err != nil {
+		t.Fatalf("seed RD: %v", err)
+	}
+
+	if err := st.Snapshots().Create(ctx, &apiv1.Snapshot{
+		Name:         "snap-1",
+		ResourceName: "pvc-1",
+		Nodes:        []string{"n1", "n2"},
+		VolumeDefinitions: []apiv1.SnapshotVolumeDef{
+			{VolumeNumber: 0, SizeKib: 1024 * 1024},
+		},
+	}); err != nil {
+		t.Fatalf("seed snap: %v", err)
+	}
+
+	base, stop := startServerWithStore(t, st)
+	defer stop()
+
+	body, _ := json.Marshal(map[string]string{
+		"to_resource":   "pvc-2",
+		"from_snapshot": "snap-1",
+	})
+
+	resp := httpPost(t, base+"/v1/resource-definitions/pvc-1/snapshot-restore-resource", body)
+	_ = resp.Body.Close()
+
+	if resp.StatusCode != http.StatusCreated {
+		t.Fatalf("status: got %d, want 201", resp.StatusCode)
+	}
+
+	got, err := st.ResourceDefinitions().Get(ctx, "pvc-2")
+	if err != nil {
+		t.Fatalf("expected pvc-2 to exist: %v", err)
+	}
+
+	if got.Name != "pvc-2" {
+		t.Errorf("Name: got %q", got.Name)
+	}
+}
+
+// TestSnapshotRestoreUnknownSnapshot: 404 if the snapshot doesn't exist.
+func TestSnapshotRestoreUnknownSnapshot(t *testing.T) {
+	st := store.NewInMemory()
+	if err := st.ResourceDefinitions().Create(t.Context(), &apiv1.ResourceDefinition{Name: "pvc-1"}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+
+	base, stop := startServerWithStore(t, st)
+	defer stop()
+
+	body, _ := json.Marshal(map[string]string{
+		"to_resource":   "pvc-2",
+		"from_snapshot": "ghost",
+	})
+
+	resp := httpPost(t, base+"/v1/resource-definitions/pvc-1/snapshot-restore-resource", body)
+	_ = resp.Body.Close()
+
+	if resp.StatusCode != http.StatusNotFound {
+		t.Errorf("status: got %d, want 404", resp.StatusCode)
+	}
+}
+
+// TestSnapshotRestoreMissingFields: empty `to_resource` → 400.
+func TestSnapshotRestoreMissingFields(t *testing.T) {
+	st := store.NewInMemory()
+	if err := st.ResourceDefinitions().Create(t.Context(), &apiv1.ResourceDefinition{Name: "pvc-1"}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+
+	base, stop := startServerWithStore(t, st)
+	defer stop()
+
+	body, _ := json.Marshal(map[string]string{
+		"from_snapshot": "snap-1",
+	})
+
+	resp := httpPost(t, base+"/v1/resource-definitions/pvc-1/snapshot-restore-resource", body)
+	_ = resp.Body.Close()
+
+	if resp.StatusCode != http.StatusBadRequest {
+		t.Errorf("status: got %d, want 400", resp.StatusCode)
+	}
+}