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unkinben 2deea3e023
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Roll pods on config change via a pod-template config hash
Pods copy config from the projected volume into an emptyDir once at
startup, so a ConfigMap or keys.conf change never reaches a running pod:
rndc reconfig re-reads the stale startup copy, and a manual
`kubectl rollout restart` is reverted because the operator overwrites the
pod template every reconcile. The only thing that applies new config is a
restart, and nothing triggered one.

Stamp a hash of the projected config (rendered ConfigMap + keys.conf
Secret) onto the pod template as bind.unkin.net/config-hash. When config
changes the hash flips, the template changes, and the StatefulSet does a
normal rolling restart so every pod re-copies fresh config. The operator
owns the template, so the restart is operator-driven and not reverted; a
stable hash means no spurious restarts.

Covers named.conf changes (ACLs, views, forwarders, validate-except,
primary address) and TSIG key rotation.
2026-07-12 22:40:02 +10:00

65 lines
2.1 KiB
Go

package controller
import (
"context"
"testing"
corev1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime"
clientgoscheme "k8s.io/client-go/kubernetes/scheme"
"sigs.k8s.io/controller-runtime/pkg/client/fake"
bindv1alpha1 "git.unkin.net/unkin/bind-operator/api/v1alpha1"
)
func TestConfigHashStableAndSensitive(t *testing.T) {
scheme := runtime.NewScheme()
if err := clientgoscheme.AddToScheme(scheme); err != nil {
t.Fatal(err)
}
if err := bindv1alpha1.AddToScheme(scheme); err != nil {
t.Fatal(err)
}
cluster := &bindv1alpha1.BindCluster{ObjectMeta: metav1.ObjectMeta{Name: "c", Namespace: "ns"}}
cm := &corev1.ConfigMap{
ObjectMeta: metav1.ObjectMeta{Name: configMapName("c"), Namespace: "ns"},
Data: map[string]string{"named.conf.secondary": "options { recursion yes; };"},
}
keys := &corev1.Secret{
ObjectMeta: metav1.ObjectMeta{Name: keysSecretName("c"), Namespace: "ns"},
Data: map[string][]byte{"keys.conf": []byte("key x {};")},
}
c := fake.NewClientBuilder().WithScheme(scheme).WithObjects(cm, keys).Build()
r := &BindClusterReconciler{Client: c, Scheme: scheme}
ctx := context.Background()
h1 := r.configHash(ctx, cluster)
if h1 == "" {
t.Fatal("hash should not be empty when config exists")
}
// Stable across calls when nothing changes.
if h2 := r.configHash(ctx, cluster); h2 != h1 {
t.Fatalf("hash not stable: %s != %s", h1, h2)
}
// A config change flips the hash (this is what rolls the StatefulSet).
cm.Data["named.conf.secondary"] = "options { recursion yes; validate-except { unkin.net; }; };"
if err := c.Update(ctx, cm); err != nil {
t.Fatal(err)
}
if h3 := r.configHash(ctx, cluster); h3 == h1 {
t.Fatal("hash must change when the ConfigMap changes")
}
// A TSIG key (keys.conf) change also flips it.
afterCM := r.configHash(ctx, cluster)
keys.Data["keys.conf"] = []byte("key x { algorithm hmac-sha256; };")
if err := c.Update(ctx, keys); err != nil {
t.Fatal(err)
}
if h4 := r.configHash(ctx, cluster); h4 == afterCM {
t.Fatal("hash must change when keys.conf changes")
}
}