[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

@@ -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
 ...

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

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:

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
 ...