From 14b84a79db0d134838be14eaa0b3ad01f5f8c93d Mon Sep 17 00:00:00 2001
From: Vasyl Saienko <vsaienko@mirantis.com>
Date: Sat, 14 Sep 2024 15:48:32 +0000
Subject: [PATCH] [memcached] Change deployment type to statefulset

For effective cache use all endpoints should be specified
explicitly as memcache client use specific algorithm to
identify on which cache server key is stored based on
servers availability and key name.
If memcached deployed behind the service unless same key is
stored on all memcached instances clients will always got
cache misses and will require to use heavy calls to database.
So in the end all keys will be stored on all memcached instances.
Furthermore delete operations such as revoke token or remove
keystone group call logic in service to remove data from cache
if Loadbalancer is used this functionality can't work as we
can't remove keys from all backends behind LB with single call.

Change-Id: I253cfa2740fed5e1c70ced7308a489568e0f10b9
---
 memcached/Chart.yaml                          |  2 +-
 .../{deployment.yaml => statefulset.yaml}     | 30 ++++++++++++-------
 memcached/values.yaml                         | 24 ++++++++++++++-
 releasenotes/notes/memcached.yaml             |  1 +
 4 files changed, 45 insertions(+), 12 deletions(-)
 rename memcached/templates/{deployment.yaml => statefulset.yaml} (77%)

diff --git a/memcached/Chart.yaml b/memcached/Chart.yaml
index 8263c2ab3..76f2bc73a 100644
--- a/memcached/Chart.yaml
+++ b/memcached/Chart.yaml
@@ -15,6 +15,6 @@ apiVersion: v1
 appVersion: v1.5.5
 description: OpenStack-Helm Memcached
 name: memcached
-version: 0.1.15
+version: 0.1.16
 home: https://github.com/memcached/memcached
 ...
diff --git a/memcached/templates/deployment.yaml b/memcached/templates/statefulset.yaml
similarity index 77%
rename from memcached/templates/deployment.yaml
rename to memcached/templates/statefulset.yaml
index b3d12eaf3..f9dd19580 100644
--- a/memcached/templates/deployment.yaml
+++ b/memcached/templates/statefulset.yaml
@@ -18,7 +18,18 @@ limitations under the License.
 {{- $_ := set . "deployment_name" .Release.Name }}
 {{- end }}
 
-{{- if .Values.manifests.deployment }}
+{{- define "memcachedProbeTemplate" }}
+tcpSocket:
+  port: {{ tuple "oslo_cache" "internal" "memcache" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
+{{- end }}
+
+{{- define "exporterProbeTemplate" }}
+httpGet:
+  path: /metrics
+  port: {{ tuple "oslo_cache" "internal" "metrics" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
+{{- end }}
+
+{{- if .Values.manifests.statefulset }}
 {{- $envAll := . }}
 
 {{- $rcControllerName := printf "%s-%s" $envAll.deployment_name "memcached" }}
@@ -27,7 +38,7 @@ limitations under the License.
 {{ tuple $envAll "memcached" $rcControllerName | include "helm-toolkit.snippets.kubernetes_pod_rbac_serviceaccount" }}
 ---
 apiVersion: apps/v1
-kind: Deployment
+kind: StatefulSet
 metadata:
   name: {{ $rcControllerName | quote }}
   annotations:
@@ -35,7 +46,9 @@ metadata:
   labels:
 {{ tuple $envAll "memcached" "server" | include "helm-toolkit.snippets.kubernetes_metadata_labels" | indent 4 }}
 spec:
+  podManagementPolicy: Parallel
   replicas: {{ .Values.pod.replicas.server }}
+  serviceName: "{{ tuple "oslo_cache" "internal" . | include "helm-toolkit.endpoints.hostname_short_endpoint_lookup" }}"
   selector:
     matchLabels:
 {{ tuple $envAll "memcached" "server" | include "helm-toolkit.snippets.kubernetes_metadata_labels" | indent 6 }}
@@ -79,9 +92,8 @@ spec:
             - /tmp/memcached.sh
           ports:
             - containerPort: {{ tuple "oslo_cache" "internal" "memcache" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
-          readinessProbe:
-            tcpSocket:
-              port: {{ tuple "oslo_cache" "internal" "memcache" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
+{{ dict "envAll" $envAll "component" "memcached" "container" "memcached" "type" "readiness" "probeTemplate" (include "memcachedProbeTemplate" $envAll | fromYaml) | include "helm-toolkit.snippets.kubernetes_probe" | indent 10 }}
+{{ dict "envAll" $envAll "component" "memcached" "container" "memcached" "type" "liveness" "probeTemplate" (include "memcachedProbeTemplate" $envAll | fromYaml) | include "helm-toolkit.snippets.kubernetes_probe" | indent 10 }}
           volumeMounts:
             - name: pod-tmp
               mountPath: /tmp
@@ -91,8 +103,7 @@ spec:
               readOnly: true
 {{- if .Values.monitoring.prometheus.enabled }}
         - name: memcached-exporter
-          image: {{ .Values.images.tags.prometheus_memcached_exporter }}
-          imagePullPolicy: {{ .Values.images.pull_policy }}
+{{ tuple $envAll "prometheus_memcached_exporter" | include "helm-toolkit.snippets.image" | indent 10 }}
 {{ tuple $envAll $envAll.Values.pod.resources.prometheus_memcached_exporter | include "helm-toolkit.snippets.kubernetes_resources" | indent 10 }}
 {{ dict "envAll" $envAll "application" "server" "container" "memcached_exporter" | include "helm-toolkit.snippets.kubernetes_container_security_context" | indent 10 }}
           command:
@@ -101,9 +112,8 @@ spec:
           ports:
             - name: metrics
               containerPort: {{ tuple "oslo_cache" "internal" "metrics" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
-          readinessProbe:
-            tcpSocket:
-              port: {{ tuple "oslo_cache" "internal" "metrics" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
+{{ dict "envAll" $envAll "component" "memcached" "container" "memcached_exporter" "type" "readiness" "probeTemplate" (include "exporterProbeTemplate" $envAll | fromYaml) | include "helm-toolkit.snippets.kubernetes_probe" | indent 10 }}
+{{ dict "envAll" $envAll "component" "memcached" "container" "memcached_exporter" "type" "liveness" "probeTemplate" (include "exporterProbeTemplate" $envAll | fromYaml) | include "helm-toolkit.snippets.kubernetes_probe" | indent 10 }}
           volumeMounts:
             - name: pod-tmp
               mountPath: /tmp
diff --git a/memcached/values.yaml b/memcached/values.yaml
index f2e6d8fd2..7c0102e5c 100644
--- a/memcached/values.yaml
+++ b/memcached/values.yaml
@@ -139,7 +139,7 @@ labels:
 
 manifests:
   configmap_bin: true
-  deployment: true
+  statefulset: true
   job_image_repo_sync: true
   network_policy: false
   service: true
@@ -157,6 +157,28 @@ pod:
         memcached_exporter:
           allowPrivilegeEscalation: false
           readOnlyRootFilesystem: true
+  probes:
+    memcached:
+      memcached:
+        readiness:
+          enabled: True
+          params:
+            initialDelaySeconds: 0
+            periodSeconds: 10
+            timeoutSeconds: 5
+      memcached_exporter:
+        liveness:
+          enabled: True
+          params:
+            initialDelaySeconds: 15
+            periodSeconds: 60
+            timeoutSeconds: 10
+        readiness:
+          enabled: True
+          params:
+            initialDelaySeconds: 5
+            periodSeconds: 60
+            timeoutSeconds: 10
   affinity:
     anti:
       topologyKey:
diff --git a/releasenotes/notes/memcached.yaml b/releasenotes/notes/memcached.yaml
index 9b3b939af..6554a5b68 100644
--- a/releasenotes/notes/memcached.yaml
+++ b/releasenotes/notes/memcached.yaml
@@ -16,4 +16,5 @@ memcached:
   - 0.1.13 Replace node-role.kubernetes.io/master with control-plane
   - 0.1.14 Use quay.io/airshipit/kubernetes-entrypoint:latest-ubuntu_focal by default
   - 0.1.15 Allow to pass additional service parameters
+  - 0.1.16 Change deployment type to statefulset
 ...