fix(kube): retry server-side apply update on ResourceQuota conflict

The update path (Client.Update, used by helm upgrade) never got the
retry.OnError wrapper around patchResourceServerSide that PR #32088
added to the create path for the same ResourceQuota admission
controller conflict class. Add the same wrapper to the update path.

Fail-before/pass-after proven with a new regression test.

Signed-off-by: zanarelli <zanarelli.dev@gmail.com>

pkg/kube/client.go

@@ -885,7 +885,12 @@ func (c *Client) Update(originals, targets ResourceList, options ...ClientUpdate
 					}
 				}
 
-				if err := patchResourceServerSide(target, updateOptions.dryRun, updateOptions.forceConflicts, updateOptions.fieldValidationDirective); err != nil {
+				if err := retry.OnError(
+					retry.DefaultRetry,
+					isServerSideRetryable,
+					func() error {
+						return patchResourceServerSide(target, updateOptions.dryRun, updateOptions.forceConflicts, updateOptions.fieldValidationDirective)
+					}); err != nil {
 					logger.Debug("Error patching resource", slog.Any("error", err))
 					return err
 				}

pkg/kube/client_update_ssa_retry_test.go

@@ -0,0 +1,89 @@
+/*
+Copyright The Helm Authors.
+
+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 kube
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"k8s.io/client-go/rest/fake"
+	"k8s.io/client-go/util/retry"
+	cmdtesting "k8s.io/kubectl/pkg/cmd/testing"
+)
+
+// TestUpdateServerSideApplyRetriesOnResourceQuotaConflict is a regression
+// test for the *update* (patch) path of server-side apply.
+//
+// PR #32088 (fixing issue #32087) added a retry.OnError wrapper around
+// patchResourceServerSide in makeCreateApplyFunc, so that transient 409
+// conflicts on a ResourceQuota's optimistic lock (see
+// https://github.com/kubernetes/kubernetes/issues/67761) are retried when
+// *creating* a resource via server-side apply.
+//
+// The exact same patchResourceServerSide call also happens in
+// makeUpdateApplyFunc (used by every `helm upgrade` that patches an
+// already-existing resource), but that call site was not given the same
+// retry wrapper. This test proves that gap: a resourcequota conflict on the
+// update path currently fails immediately instead of retrying.
+func TestUpdateServerSideApplyRetriesOnResourceQuotaConflict(t *testing.T) {
+	c := newTestClient(t)
+
+	pods := newPodList("otter")
+
+	cb := func(_ []RequestResponseAction, req *http.Request) (*http.Response, error) {
+		p, m := req.URL.Path, req.Method
+		switch {
+		case p == "/namespaces/default/pods/otter" && m == http.MethodGet:
+			return newResponse(http.StatusOK, &pods.Items[0])
+		case p == "/namespaces/default/pods/otter" && m == http.MethodPatch:
+			return newResponseJSON(http.StatusConflict, resourceQuotaConflict)
+		}
+		t.Fatalf("unexpected request: %s %s", m, p)
+		return nil, nil
+	}
+
+	client := NewRequestResponseLogClient(t, cb)
+	c.Factory.(*cmdtesting.TestFactory).UnstructuredClient = &fake.RESTClient{
+		NegotiatedSerializer: unstructuredSerializer,
+		Client:               fake.CreateHTTPClient(client.Do),
+	}
+
+	originals, err := c.Build(objBody(&pods), false)
+	require.NoError(t, err)
+	targets, err := c.Build(objBody(&pods), false)
+	require.NoError(t, err)
+
+	_, err = c.Update(
+		originals,
+		targets,
+		ClientUpdateOptionServerSideApply(true, false),
+	)
+	require.ErrorContains(t, err, "Operation cannot be fulfilled on resourcequotas")
+
+	patchCount := 0
+	for _, action := range client.Actions {
+		if action.Request.URL.Path == "/namespaces/default/pods/otter" && action.Request.Method == http.MethodPatch {
+			patchCount++
+		}
+	}
+
+	assert.Equal(t, retry.DefaultRetry.Steps, patchCount,
+		"expected helm to retry the server-side apply PATCH on a resourcequota conflict during update, the same way it already does during create")
+}