fix: use kustomize build with --load-restrictor for deploy

Kustomize 5.x enforces LoadRestrictionsRootOnly by default, which
blocks configMapGenerator references to files outside the kustomization
root (base references ../../../configs/). Use kustomize standalone
with --load-restrictor LoadRestrictionsNone instead of kubectl apply -k.

Affected:
- .github/workflows/e2e.yml: install kustomize, use kustomize build
- Makefile: conformance target
- test/e2e/smoke/run.sh: deploy_gateway

Author: mahmut-Abi

.github/workflows/e2e.yml

@@ -42,9 +42,14 @@ jobs:
             kind load docker-image "ghcr.io/nantian-gw/${img}:latest" --name e2e
           done
 
+      - name: Install kustomize
+        run: |
+          curl -sL "https://github.com/kubernetes-sigs/kustomize/releases/download/kustomize%2Fv5.7.1/kustomize_v5.7.1_linux_amd64.tar.gz" | tar xz
+          sudo mv kustomize /usr/local/bin/
+
       - name: Deploy nantian-gw
         run: |
-          kubectl apply -k deploy/kubernetes/overlays/kind-conformance
+          kustomize build deploy/kubernetes/overlays/kind-conformance --load-restrictor LoadRestrictionsNone | kubectl apply -f -
           kubectl wait --for=condition=ready pod --all -n nantian-gw --timeout=300s
 
       - name: Record image versions

Makefile

@@ -19,7 +19,7 @@ conformance:
 	@echo "=== Installing Gateway API CRDs ==="
 	kubectl apply -f $(GATEWAY_API_CRDS)
 	@echo "=== Deploying nantian-gw ==="
-	kubectl apply -k deploy/kubernetes/overlays/kind-conformance
+	kustomize build deploy/kubernetes/overlays/kind-conformance --load-restrictor LoadRestrictionsNone | kubectl apply -f -
 	kubectl wait --for=condition=ready pod --all -n nantian-gw --timeout=180s
 	@echo "=== Running conformance tests ==="
 	go test -tags=conformance -count=1 -v -timeout 30m ./conformance/

test/e2e/smoke/run.sh

@@ -62,7 +62,7 @@ deploy_gateway() {
         return
     fi
     echo "=== Deploying nantian-gw ==="
-    kubectl apply -k "$GATEWAY_ROOT/deploy/kubernetes/overlays/kind-conformance"
+    kustomize build "$GATEWAY_ROOT/deploy/kubernetes/overlays/kind-conformance" --load-restrictor LoadRestrictionsNone | kubectl apply -f -
     kubectl wait --for=condition=ready pod --all -n "$CONTROL_PLANE_NS" --timeout="${TIMEOUT}s"
 }