fix: hash drift, transformer leak guard, prod logger, ctx-aware wait

M7: extractUnstructuredContent only hashed 'spec' when present, dropping
all other top-level content fields. Resources with both spec and data
(or any non-spec content) silently drifted until the next 10m resync.
Now hashes every non-Kubernetes-managed top-level field, matching the
fields updateUnstructuredMirror copies.

M6: when a source has a transform annotation, also hash the source's
labels and annotations (filtered of kubemirror.raczylo.com/* keys to
avoid the controller's own bookkeeping churning the hash). Templates
read these via TransformContext; without this a label change wouldn't
re-render the transformed mirror.

H3: text/template.Execute is not context-aware, so applyTemplateRule's
timeout cancels the select but leaks the executor goroutine. Added a
process-wide semaphore (cap 64) so a runaway template can't spawn an
unbounded number of stuck goroutines on every reconcile.

M4: zap dev mode (DPanic-on-error, console output, stacktraces on
warning) was hardcoded on. Defaulted to production; --zap-devel flag
remains for opt-in.

M5: WaitForInitialDiscovery was anchored on context.Background() with
its own WithTimeout, so SIGTERM during startup couldn't abort the wait.
Now anchors on signalCtx.
This commit is contained in:
2026-05-02 22:49:15 +01:00
parent cf095e93f4
commit 75f7c18f3c
5 changed files with 188 additions and 30 deletions
+46 -25
View File
@@ -6,6 +6,7 @@ import (
"encoding/hex"
"encoding/json"
"fmt"
"strings"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -85,50 +86,70 @@ func extractConfigMapContent(cm *corev1.ConfigMap) map[string]interface{} {
}
// extractUnstructuredContent extracts content from an unstructured resource (CRDs, etc.).
//
// Hashes every non-Kubernetes-managed field at the top level — not only spec
// — so resources with both spec and data (e.g. an unstructured Secret/CM, or
// a CRD using a custom schema) detect drift on every content field, matching
// the fields that updateUnstructuredMirror copies to the mirror.
//
// When a transform annotation is present the source's labels and annotations
// are also folded into the hash, because templates can read them via
// TransformContext.Labels / .Annotations and a label change would otherwise
// be invisible to NeedsSync.
func extractUnstructuredContent(obj runtime.Object) (interface{}, error) {
// Convert to unstructured
unstructuredObj, err := runtime.DefaultUnstructuredConverter.ToUnstructured(obj)
if err != nil {
return nil, fmt.Errorf("failed to convert to unstructured: %w", err)
}
u := &unstructured.Unstructured{Object: unstructuredObj}
// Make a deep copy to avoid race conditions when accessing nested fields
// NestedMap modifies the underlying map, so we need our own copy
uCopy := u.DeepCopy()
// (NestedMap may modify the underlying map).
u := (&unstructured.Unstructured{Object: unstructuredObj}).DeepCopy()
// Extract spec (most resources have spec)
spec, found, err := unstructured.NestedMap(uCopy.Object, "spec")
if err != nil {
return nil, fmt.Errorf("failed to extract spec: %w", err)
skipFields := map[string]bool{
"metadata": true,
"status": true,
"apiVersion": true,
"kind": true,
}
content := make(map[string]interface{})
if found {
content["spec"] = spec
}
// For resources without spec, include all fields except metadata and status
if !found {
for key, value := range uCopy.Object {
if key != "metadata" && key != "status" && key != "apiVersion" && key != "kind" {
content[key] = value
}
for key, value := range u.Object {
if !skipFields[key] {
content[key] = value
}
}
// Include transform annotation in hash so changes to transformation rules trigger updates
annotations := uCopy.GetAnnotations()
if annotations != nil {
if transform, exists := annotations[constants.AnnotationTransform]; exists {
content["transform"] = transform
}
annotations := u.GetAnnotations()
if transform, exists := annotations[constants.AnnotationTransform]; exists && transform != "" {
content["transform"] = transform
// Templates can read source labels and annotations; include them so a
// label/annotation change triggers re-render of transformed mirrors.
// Filter out the kubemirror.raczylo.com/* keys to avoid the source's
// own bookkeeping (sync-status annotation, etc.) churning the hash.
content["sourceLabels"] = filterKubeMirror(u.GetLabels())
content["sourceAnnotations"] = filterKubeMirror(annotations)
}
return content, nil
}
// filterKubeMirror returns a copy of m with all kubemirror.raczylo.com/* keys
// removed. Used to exclude controller-managed keys from content hashing so
// the controller's own writes don't churn the hash.
func filterKubeMirror(m map[string]string) map[string]string {
if len(m) == 0 {
return nil
}
out := make(map[string]string, len(m))
for k, v := range m {
if !strings.HasPrefix(k, constants.Domain+"/") {
out[k] = v
}
}
return out
}
// NeedsSync determines if a target resource needs to be synced based on content changes.
// It uses a multi-layer strategy:
// 1. Check generation field (if available) - fastest
+73
View File
@@ -641,3 +641,76 @@ func BenchmarkNeedsSync(b *testing.B) {
_, _ = NeedsSync(source, target, annotations)
}
}
func TestComputeContentHash_Unstructured_HashesAllNonMetaFields(t *testing.T) {
// Regression (M7): the previous implementation only hashed `spec` when it
// was present, dropping any other top-level content (data, type, custom
// CRD fields). Drift to those fields was invisible until the next resync.
objSpecOnly := &unstructured.Unstructured{Object: map[string]interface{}{
"apiVersion": "v1",
"kind": "Custom",
"spec": map[string]interface{}{"field": "v1"},
"data": map[string]interface{}{"k": "v1"},
}}
objSpecAndDifferentData := &unstructured.Unstructured{Object: map[string]interface{}{
"apiVersion": "v1",
"kind": "Custom",
"spec": map[string]interface{}{"field": "v1"},
"data": map[string]interface{}{"k": "v2"}, // only data differs
}}
h1, err := ComputeContentHash(objSpecOnly)
require.NoError(t, err)
h2, err := ComputeContentHash(objSpecAndDifferentData)
require.NoError(t, err)
assert.NotEqual(t, h1, h2, "data field must contribute to hash even when spec exists")
}
func TestComputeContentHash_Unstructured_TransformIncludesLabelsAndAnnotations(t *testing.T) {
// Regression (M6): templates can read source labels/annotations via
// TransformContext. When a transform annotation is present, label /
// annotation changes must therefore re-hash so NeedsSync re-renders.
make := func(label, annot string) *unstructured.Unstructured {
return &unstructured.Unstructured{Object: map[string]interface{}{
"apiVersion": "v1",
"kind": "ConfigMap",
"metadata": map[string]interface{}{
"labels": map[string]interface{}{"app": label},
"annotations": map[string]interface{}{constants.AnnotationTransform: "rules: []", "tier": annot},
},
"data": map[string]interface{}{"k": "v"},
}}
}
base, err := ComputeContentHash(make("v1", "prod"))
require.NoError(t, err)
labelChanged, err := ComputeContentHash(make("v2", "prod"))
require.NoError(t, err)
assert.NotEqual(t, base, labelChanged, "label change must re-hash when transform is present")
annotChanged, err := ComputeContentHash(make("v1", "stage"))
require.NoError(t, err)
assert.NotEqual(t, base, annotChanged, "annotation change must re-hash when transform is present")
}
func TestComputeContentHash_Unstructured_LabelChangesIgnoredWithoutTransform(t *testing.T) {
// Counterpart to the above: when there is NO transform annotation, label
// changes must NOT churn the hash — that would cause unnecessary mirror
// re-writes for plain (non-transformed) mirrors.
make := func(label string) *unstructured.Unstructured {
return &unstructured.Unstructured{Object: map[string]interface{}{
"apiVersion": "v1",
"kind": "ConfigMap",
"metadata": map[string]interface{}{
"labels": map[string]interface{}{"app": label},
},
"data": map[string]interface{}{"k": "v"},
}}
}
h1, err := ComputeContentHash(make("v1"))
require.NoError(t, err)
h2, err := ComputeContentHash(make("v2"))
require.NoError(t, err)
assert.Equal(t, h1, h2, "label changes must not re-hash without a transform annotation")
}