StatefulSet

Default version: apps/v1

• Official Documentation

• PHP K8s Pod Kind

• PHP K8s PersistentVolumeClaim Kind

• PHP K8s Service Kind

Example

use RenokiCo\PhpK8s\K8s;

$container = K8s::container()
    ->setName('mysql')
    ->setImage('mysql', '5.7')
    ->setPorts([
        ['name' => 'mysql', 'protocol' => 'TCP', 'containerPort' => 3306],
    ]);

$pod = K8s::pod()
    ->setName('mysql')
    ->setLabels(['statefulset-name' => 'mysql']) // needs statefulset-name: mysql so that ->getPods() can work
    ->setContainers([$mysql]);

$svc = $this->cluster
    ->service()
    ->setName('mysql')
    ->setPorts([
        ['protocol' => 'TCP', 'port' => 3306, 'targetPort' => 3306],
    ])->create();

$pvc = $this->cluster
    ->persistentVolumeClaim()
    ->setName('mysql-pvc')
    ->setCapacity(1, 'Gi')
    ->setAccessModes(['ReadWriteOnce'])
    ->create();

$sts = $this->cluster
    ->statefulSet()
    ->setName('mysql')
    ->setSelectors(['matchLabels' => ['tier' => 'backend']])
    ->setReplicas(1)
    ->setService($svc)
    ->setTemplate($pod)
    ->setVolumeClaims([$pvc])
    ->create();

Pod Template Retrieval

Stateful Sets rely on pods, so you can get the pod template as K8sPod class:

$template = $sts->getTemplate();

$podName = $template->getName();

To retrieve the pod template as an array, pass false to the retrieval method:

$pod = $sts->getTemplate(false);

$podName = $template['name'];

Getting Pods

To get the pods, the Pod template must have the statefulset-name label set. This way, the labelSelector API parameter is issued and you may retrieve the associated pods:

metadata:
  name: [here it goes the statefulset name]
spec:
  template:
    metadata:
      labels:
        statefulset-name: [here it goes the statefulset name]

You can retrieve the pods as resources controlled by the Stateful Set by issuing ->getPods():

foreach ($sts->getPods() as $pod) {
    // $pod->logs()
}

Custom Pod Labels

If you cannot declare the statefulset-name label or simply want to use something else, you may call selectPods from the resource:

use RenokiCo\PhpK8s\Kinds\K8sStatefulSet;

K8sStatefulSet::selectPods(function (K8sStatefulSet $sts) {
    // $sts is the current StatefulSet

    return [
        'some-label' => 'some-label-value',
        'some-other-label' => "{$sts->getName()}-custom-name",
    ];
});

Scaling

The Scaling API is available via a K8sScale resource:

$scaler = $sts->scaler();

$scaler->setReplicas(3)->update(); // autoscale the Stateful Set to 3 replicas

Shorthand, you can use scale() directly from the Stateful Set:

$scaler = $sts->scale(3);

$pods = $sts->getPods(); // Expecting 3 pods

StatefulSet Status

The Status API is available to be accessed for fresh instances:

$sts->refresh();

$sts->getCurrentReplicasCount();
$sts->getReadyReplicasCount();
$sts->getDesiredReplicasCount();

You can check if all the pods within the StatefulSet are running:

if ($sts->allPodsAreRunning()) {
    //
}