Add resize volume functionality to Logstash operator

cmd/manager/main.go

@@ -82,6 +82,7 @@ import (
 	"github.com/elastic/cloud-on-k8s/v2/pkg/controller/kibana"
 	"github.com/elastic/cloud-on-k8s/v2/pkg/controller/license"
 	licensetrial "github.com/elastic/cloud-on-k8s/v2/pkg/controller/license/trial"
+	lsvalidation "github.com/elastic/cloud-on-k8s/v2/pkg/controller/logstash/validation"
 	"github.com/elastic/cloud-on-k8s/v2/pkg/controller/maps"
 	"github.com/elastic/cloud-on-k8s/v2/pkg/controller/remoteca"
 	"github.com/elastic/cloud-on-k8s/v2/pkg/controller/stackconfigpolicy"
@@ -1011,7 +1012,6 @@ func setupWebhook(
 		&kbv1.Kibana{},
 		&kbv1beta1.Kibana{},
 		&emsv1alpha1.ElasticMapsServer{},
-		&logstashv1alpha1.Logstash{},
 		&policyv1alpha1.StackConfigPolicy{},
 	}
 	for _, obj := range webhookObjects {
@@ -1027,9 +1027,10 @@ func setupWebhook(
 		}
 	}
 
-	// Elasticsearch and ElasticsearchAutoscaling validating webhooks are wired up differently, in order to access the k8s client
+	// Logstash, Elasticsearch and ElasticsearchAutoscaling validating webhooks are wired up differently, in order to access the k8s client
 	esvalidation.RegisterWebhook(mgr, params.ValidateStorageClass, exposedNodeLabels, checker, managedNamespaces)
 	esavalidation.RegisterWebhook(mgr, params.ValidateStorageClass, checker, managedNamespaces)
+	lsvalidation.RegisterWebhook(mgr, params.ValidateStorageClass, managedNamespaces)
 
 	// wait for the secret to be populated in the local filesystem before returning
 	interval := time.Second * 1

config/webhook/manifests.yaml

@@ -202,28 +202,6 @@ webhooks:
     resources:
     - kibanas
   sideEffects: None
-- admissionReviewVersions:
-  - v1
-  - v1beta1
-  clientConfig:
-    service:
-      name: webhook-service
-      namespace: system
-      path: /validate-logstash-k8s-elastic-co-v1alpha1-logstash
-  failurePolicy: Ignore
-  matchPolicy: Exact
-  name: elastic-logstash-validation-v1alpha1.k8s.elastic.co
-  rules:
-  - apiGroups:
-    - logstash.k8s.elastic.co
-    apiVersions:
-    - v1alpha1
-    operations:
-    - CREATE
-    - UPDATE
-    resources:
-    - logstashes
-  sideEffects: None
 - admissionReviewVersions:
   - v1
   - v1beta1
@@ -312,3 +290,25 @@ webhooks:
     resources:
     - elasticsearchautoscalers
   sideEffects: None
+- admissionReviewVersions:
+  - v1
+  - v1beta1
+  clientConfig:
+    service:
+      name: webhook-service
+      namespace: system
+      path: /validate-logstash-k8s-elastic-co-v1alpha1-logstash
+  failurePolicy: Ignore
+  matchPolicy: Exact
+  name: elastic-logstash-validation-v1alpha1.k8s.elastic.co
+  rules:
+  - apiGroups:
+    - logstash.k8s.elastic.co
+    apiVersions:
+    - v1alpha1
+    operations:
+    - CREATE
+    - UPDATE
+    resources:
+    - logstashes
+  sideEffects: None

docs/orchestrating-elastic-stack-applications/logstash.asciidoc

@@ -444,10 +444,18 @@ spec:
 [discrete]
 == Updating the volume claim settings
 
-Changes, such as storage class or volume size, are currently forbidden in `spec.volumeClaimTemplates`.
-To make these changes, you have to fully delete the {ls} resource, delete and recreate or resize the volume, and create a new {ls} resource.
+If the storage class allows link:https://kubernetes.io/blog/2018/07/12/resizing-persistent-volumes-using-kubernetes/[volume expansion], you can increase the storage requests size in `spec.volumeClaimTemplates`. 
+ECK updates the existing PersistentVolumeClaims accordingly, and recreates the StatefulSet automatically. 
 
-Before deleting or resizing a persistent queue (PQ) volume, ensure that the queue is empty.
+If the volume driver supports `ExpandInUsePersistentVolumes`, the filesystem is resized online.
+In this case, you do not need to restart the {ls} process or re-create the Pods. 
+
+If the volume driver does not support `ExpandInUsePersistentVolumes`, you must manually delete Pods after the resize so that they can be recreated automatically with the expanded filesystem.
+
+Any other changes in the volumeClaimTemplates--such as changing the storage class or decreasing the volume size--are not allowed. 
+To make changes such as these, you must fully delete the {ls} resource, delete and recreate or resize the volume, and create a new {ls} resource.
+
+Before you delete a persistent queue (PQ) volume, ensure that the queue is empty.
 When using the PQ, we recommend setting `queue.drain: true` on the {ls} Pods to ensure that the queue is drained when Pods are shutdown.
 Note that you should also increase the `terminationGracePeriodSeconds` to a large enough value to allow the queue to drain.
 

pkg/apis/logstash/v1alpha1/labels.go

@@ -15,3 +15,12 @@ func (logstash *Logstash) GetIdentityLabels() map[string]string {
 		"logstash.k8s.elastic.co/name": logstash.Name,
 	}
 }
+
+// GetPodIdentityLabels will return the common Elastic assigned labels for a Logstash Pod
+func (logstash *Logstash) GetPodIdentityLabels() map[string]string {
+	return map[string]string{
+		commonv1.TypeLabelName:                     "logstash",
+		"logstash.k8s.elastic.co/name":             logstash.Name,
+		"logstash.k8s.elastic.co/statefulset-name": Name(logstash.Name),
+	}
+}