Sort render inputs so config is deterministic (stop restart loop)
client.List returns cache-ordered (non-deterministic) results, so the forward zones (and DNSSEC policies) reshuffled between reconciles. Before the config-hash change this was harmless, but now a reshuffled render rewrites the ConfigMap, flips the pod-template config hash, and the StatefulSet rolls forever (observed: resolver forward zones churn every reconcile, pod endlessly recreated). Sort every list rendered into named.conf (ACLs, views, forward zones, policies, DNSSEC policies) before rendering, so identical inputs always produce byte-identical config and the hash is stable.
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@@ -28,9 +28,28 @@ type RenderInput struct {
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// cluster. Both variants are shipped in the ConfigMap; the entrypoint selects
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// one based on the pod ordinal.
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func RenderNamedConf(in RenderInput) (primary string, secondary string) {
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// client.List returns cache-ordered (non-deterministic) results, so sort
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// every input slice before rendering. Otherwise the rendered config
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// reshuffles between reconciles, churning the ConfigMap — and with the
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// pod-template config hash that means an endless rolling restart.
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sortInput(&in)
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return render(in, true), render(in, false)
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}
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// sortInput orders every list rendered into named.conf deterministically.
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func sortInput(in *RenderInput) {
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sort.Slice(in.ACLs, func(i, j int) bool { return in.ACLs[i].Name < in.ACLs[j].Name })
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sort.Slice(in.Views, func(i, j int) bool {
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if in.Views[i].Spec.Order != in.Views[j].Spec.Order {
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return in.Views[i].Spec.Order < in.Views[j].Spec.Order
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}
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return in.Views[i].Name < in.Views[j].Name
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})
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sort.Slice(in.Forwards, func(i, j int) bool { return in.Forwards[i].Spec.ZoneName < in.Forwards[j].Spec.ZoneName })
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sort.Slice(in.Policies, func(i, j int) bool { return in.Policies[i].Spec.ZoneName < in.Policies[j].Spec.ZoneName })
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sort.Slice(in.DNSSECPolicies, func(i, j int) bool { return in.DNSSECPolicies[i].Name < in.DNSSECPolicies[j].Name })
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}
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func render(in RenderInput, isPrimary bool) string {
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c := in.Cluster
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var b strings.Builder
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@@ -146,3 +146,34 @@ func TestCatalogHashStable(t *testing.T) {
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t.Fatalf("expected 40-char hex sha1, got %d: %s", len(h1), h1)
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}
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}
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func TestRenderDeterministicWithShuffledForwards(t *testing.T) {
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// client.List order is non-deterministic; the render must not depend on
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// input order, or the ConfigMap churns and (with the config hash) the
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// StatefulSet rolls forever.
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mkFwd := func(zone, fwd string) bindv1alpha1.BindZone {
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return bindv1alpha1.BindZone{
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ObjectMeta: metav1.ObjectMeta{Name: zone},
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Spec: bindv1alpha1.BindZoneSpec{
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ClusterRef: "r", Type: bindv1alpha1.ZoneForward,
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ZoneName: zone, Forwarders: []string{fwd},
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},
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}
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}
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base := RenderInput{Cluster: newCluster(bindv1alpha1.ModeResolver)}
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orderA := base
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orderA.Forwards = []bindv1alpha1.BindZone{
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mkFwd("unkin.net", "198.18.200.6"), mkFwd("consul", "198.18.19.14"),
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mkFwd("k8s.syd1.au.unkin.net", "198.18.200.8"), mkFwd("13.18.198.in-addr.arpa", "198.18.200.6"),
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}
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orderB := base
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orderB.Forwards = []bindv1alpha1.BindZone{
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mkFwd("13.18.198.in-addr.arpa", "198.18.200.6"), mkFwd("k8s.syd1.au.unkin.net", "198.18.200.8"),
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mkFwd("consul", "198.18.19.14"), mkFwd("unkin.net", "198.18.200.6"),
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}
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pa, _ := RenderNamedConf(orderA)
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pb, _ := RenderNamedConf(orderB)
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if pa != pb {
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t.Fatalf("render must be independent of forward-zone input order:\n--- A ---\n%s\n--- B ---\n%s", pa, pb)
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}
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}
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