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Merged
birdayz merged 3 commits into from
Oct 9, 2025
Merged

statefulset: make pod restart detection idempotent #1133

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bf800bd
statefulset: make pod restart detection idempotent
birdayz Oct 9, 2025
f868986
statefulset: add unit test for idempotent pod restart detection
birdayz Oct 9, 2025
c123afd
Fix formatting in test file
birdayz Oct 9, 2025
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16 changes: 14 additions & 2 deletions operator/pkg/resources/statefulset_update.go
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Original file line number Diff line number Diff line change
Expand Up @@ -94,7 +94,7 @@ func (r *StatefulSetResource) runUpdate(
// Check if we should run update on this specific STS.

log.V(logger.DebugLevel).Info("Checking that we should update")
stsChanged, nodePoolRestarting, err := r.shouldUpdate(current, modified)
stsChanged, nodePoolRestarting, err := r.shouldUpdate(ctx, current, modified)
if err != nil {
return fmt.Errorf("unable to determine the update procedure: %w", err)
}
Expand Down Expand Up @@ -629,7 +629,7 @@ func (r *StatefulSetResource) updateStatefulSet(
// If no differences are found, the function returns `false` as first value. The second value
// depends on the Node Pool Status, indicating whether rolling restart is still in progress.
func (r *StatefulSetResource) shouldUpdate(
current, modified *appsv1.StatefulSet,
ctx context.Context, current, modified *appsv1.StatefulSet,
) (bool, bool, error) {
log := r.logger.WithName("shouldUpdate")

Expand All @@ -648,6 +648,18 @@ func (r *StatefulSetResource) shouldUpdate(
return false, true, nil
}

// Check if any pods have ClusterUpdate condition set.
// This makes the controller idempotent: if a previous reconcile set the condition
// but the status flag wasn't persisted (due to controller restart, stale cache, etc.),
// we'll still detect that a rolling update is needed by checking actual pod state.
allPodsUpdated, err := r.areAllPodsUpdated(ctx)
if err != nil {
log.V(logger.DebugLevel).Error(err, "error checking if pods need update")
} else if !allPodsUpdated {
log.Info("Found pods with ClusterUpdate condition, continuing rolling update")
return false, true, nil
}

return false, false, err
}
log.Info("Detected diff", "patchResult", string(patchResult.Patch))
Expand Down
125 changes: 122 additions & 3 deletions operator/pkg/resources/statefulset_update_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@ import (
"k8s.io/utils/ptr"
ctrl "sigs.k8s.io/controller-runtime"
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/client/fake"

redpanda "github.com/redpanda-data/redpanda-operator/charts/redpanda/v25/client"
vectorizedv1alpha1 "github.com/redpanda-data/redpanda-operator/operator/api/vectorized/v1alpha1"
Expand Down Expand Up @@ -146,13 +147,21 @@ func TestShouldUpdate_AnnotationChange(t *testing.T) {
}
stsWithAnnotation := sts.DeepCopy()
stsWithAnnotation.Spec.Template.Annotations = map[string]string{"test": "test2"}

fakeClient := fake.NewClientBuilder().Build()

ssres := StatefulSetResource{
Client: fakeClient,
nodePool: vectorizedv1alpha1.NodePoolSpecWithDeleted{
NodePoolSpec: vectorizedv1alpha1.NodePoolSpec{
Name: "default",
},
},
pandaCluster: &vectorizedv1alpha1.Cluster{
ObjectMeta: metav1.ObjectMeta{
Name: "test",
Namespace: "default",
},
Status: vectorizedv1alpha1.ClusterStatus{
Restarting: false,
NodePools: map[string]vectorizedv1alpha1.NodePoolStatus{
Expand All @@ -163,22 +172,27 @@ func TestShouldUpdate_AnnotationChange(t *testing.T) {
},
},
}
stsChange, _, err := ssres.shouldUpdate(sts, stsWithAnnotation)
stsChange, _, err := ssres.shouldUpdate(context.Background(), sts, stsWithAnnotation)
require.NoError(t, err)
require.True(t, stsChange)

// same statefulset with same annotation
stsChange, _, err = ssres.shouldUpdate(stsWithAnnotation, stsWithAnnotation)
stsChange, _, err = ssres.shouldUpdate(context.Background(), stsWithAnnotation, stsWithAnnotation)
require.NoError(t, err)
require.False(t, stsChange)

ssres = StatefulSetResource{
Client: fakeClient,
nodePool: vectorizedv1alpha1.NodePoolSpecWithDeleted{
NodePoolSpec: vectorizedv1alpha1.NodePoolSpec{
Name: "default",
},
},
pandaCluster: &vectorizedv1alpha1.Cluster{
ObjectMeta: metav1.ObjectMeta{
Name: "test",
Namespace: "default",
},
Status: vectorizedv1alpha1.ClusterStatus{
Restarting: false,
NodePools: map[string]vectorizedv1alpha1.NodePoolStatus{
Expand All @@ -190,7 +204,7 @@ func TestShouldUpdate_AnnotationChange(t *testing.T) {
},
}
// same statefulset with same annotation, but with node pool status restarting
_, nodePoolRestarting, err := ssres.shouldUpdate(stsWithAnnotation, stsWithAnnotation)
_, nodePoolRestarting, err := ssres.shouldUpdate(context.Background(), stsWithAnnotation, stsWithAnnotation)
require.NoError(t, err)
require.True(t, nodePoolRestarting)
}
Expand Down Expand Up @@ -385,6 +399,111 @@ vectorized_cluster_partition_under_replicated_replicas{namespace="kafka",partiti
require.NoError(t, err)
}

func TestShouldUpdate_PodsWithClusterUpdateCondition(t *testing.T) {
var replicas int32 = 3
sts := &appsv1.StatefulSet{
ObjectMeta: metav1.ObjectMeta{
Namespace: "default",
Name: "cluster-first",
},
Spec: appsv1.StatefulSetSpec{
Replicas: &replicas,
Selector: &metav1.LabelSelector{
MatchLabels: map[string]string{
"app.kubernetes.io/name": "redpanda",
"app.kubernetes.io/instance": "cluster",
"app.kubernetes.io/component": "redpanda",
"cluster.redpanda.com/nodepool": "first",
},
},
Template: corev1.PodTemplateSpec{
ObjectMeta: metav1.ObjectMeta{
Labels: map[string]string{
"app.kubernetes.io/name": "redpanda",
"app.kubernetes.io/instance": "cluster",
"app.kubernetes.io/component": "redpanda",
"cluster.redpanda.com/nodepool": "first",
},
},
Spec: corev1.PodSpec{
Containers: []corev1.Container{{Name: "redpanda", Image: "redpanda:v25.2.7"}},
},
},
},
}

// Create pods with ClusterUpdate condition set (simulating stuck state)
pods := []client.Object{
&corev1.Pod{
ObjectMeta: metav1.ObjectMeta{
Name: "cluster-first-0",
Namespace: "default",
Labels: map[string]string{
"app.kubernetes.io/name": "redpanda",
"app.kubernetes.io/instance": "cluster",
"app.kubernetes.io/component": "redpanda",
"cluster.redpanda.com/nodepool": "first",
},
},
Status: corev1.PodStatus{
Conditions: []corev1.PodCondition{
{Type: ClusterUpdatePodCondition, Status: corev1.ConditionTrue, Reason: ClusterUpdateReasonVersion},
},
},
},
&corev1.Pod{
ObjectMeta: metav1.ObjectMeta{
Name: "cluster-first-1",
Namespace: "default",
Labels: map[string]string{
"app.kubernetes.io/name": "redpanda",
"app.kubernetes.io/instance": "cluster",
"app.kubernetes.io/component": "redpanda",
"cluster.redpanda.com/nodepool": "first",
},
},
Status: corev1.PodStatus{
Conditions: []corev1.PodCondition{
{Type: ClusterUpdatePodCondition, Status: corev1.ConditionTrue, Reason: ClusterUpdateReasonVersion},
},
},
},
}

fakeClient := fake.NewClientBuilder().WithObjects(pods...).Build()

ssres := StatefulSetResource{
Client: fakeClient,
logger: ctrl.Log.WithName("test"),
nodePool: vectorizedv1alpha1.NodePoolSpecWithDeleted{
NodePoolSpec: vectorizedv1alpha1.NodePoolSpec{
Name: "first",
},
},
pandaCluster: &vectorizedv1alpha1.Cluster{
ObjectMeta: metav1.ObjectMeta{
Name: "cluster",
Namespace: "default",
},
Status: vectorizedv1alpha1.ClusterStatus{
Restarting: false, // Status says not restarting (stale cache)
NodePools: map[string]vectorizedv1alpha1.NodePoolStatus{
"first": {
Restarting: false, // NodePool status also says not restarting
},
},
},
},
}

// No StatefulSet diff, status says not restarting, but pods have ClusterUpdate condition
// Should detect this and return nodePoolRestarting=true for idempotency
stsChange, nodePoolRestarting, err := ssres.shouldUpdate(context.Background(), sts, sts)
require.NoError(t, err)
require.False(t, stsChange, "StatefulSet should not have changed")
require.True(t, nodePoolRestarting, "Should detect pods need restart despite status saying otherwise")
}

//nolint:funlen // the test data doesn't count
func Test_sortPodList(t *testing.T) {
const clusterName = "sortPodListCluster"
Expand Down
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