Make memcached a statefulset, add anti-affinity and podDisruptionBudget (#933)

* Make memcached a statefulset, add anti-affinity and podDisruptionBudget

* Address review comments

* Make the chart 1.0.0, as deploment to SS is a breaking change

* Convert anti-affinity a proper yaml format

stable/memcached/Chart.yaml

@@ -1,5 +1,5 @@
 name: memcached
-version: 0.4.1
+version: 1.0.0
 description: Free & open source, high-performance, distributed memory object caching system.
 keywords:
 - memcached

stable/memcached/templates/pdb.yaml

@@ -0,0 +1,13 @@
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  name: {{ template "fullname" . }}
+spec:
+  selector:
+    matchLabels:
+      app: {{ template "fullname" . }}
+      chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
+      release: "{{ .Release.Name }}"
+      heritage: "{{ .Release.Service }}"
+  minAvailable: {{ .Values.replicaCount }}
+  

stable/memcached/templates/statefulset.yaml

@@ -1,5 +1,5 @@
-apiVersion: extensions/v1beta1
-kind: Deployment
+apiVersion: apps/v1beta1
+kind: StatefulSet
 metadata:
   name: {{ template "fullname" . }}
   labels:
@@ -8,7 +8,8 @@ metadata:
     release: "{{ .Release.Name }}"
     heritage: "{{ .Release.Service }}"
 spec:
-  replicas: 1
+  serviceName: {{ template "fullname" . }}
+  replicas: {{ .Values.replicaCount }}
   template:
     metadata:
       labels:
@@ -17,6 +18,18 @@ spec:
         release: "{{ .Release.Name }}"
         heritage: "{{ .Release.Service }}"
     spec:
+      affinity:
+        podAntiAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+          - weight: 5
+            podAffinityTerm:
+              labelSelector:
+                matchExpressions:
+                - key: app
+                  operator: In
+                  values:
+                  -  "{{ template "fullname" . }}"  
+              topologyKey: "kubernetes.io/hostname"
       containers:
       - name: {{ template "fullname" . }}
         image: {{ .Values.image }}
@@ -41,4 +54,4 @@ spec:
           initialDelaySeconds: 5
           timeoutSeconds: 1
         resources:
-{{ toYaml .Values.resources | indent 10 }}
+{{ toYaml .Values.resources | indent 10 }}

stable/memcached/templates/svc.yaml

@@ -8,6 +8,7 @@ metadata:
     release: "{{ .Release.Name }}"
     heritage: "{{ .Release.Service }}"
 spec:
+  clusterIP: None
   ports:
   - name: memcache
     port: 11211

stable/memcached/values.yaml

@@ -1,7 +1,7 @@
 ## Memcached image and tag
 ## ref: https://hub.docker.com/r/library/memcached/tags/
 ##
-image: memcached:1.4.32
+image: memcached:1.4.36-alpine
 
 ## Specify a imagePullPolicy
 ## 'Always' if imageTag is 'latest', else set to 'IfNotPresent'
@@ -10,12 +10,15 @@ image: memcached:1.4.32
 # imagePullPolicy:
 #
 
+##Replica count 
+replicaCount: 3
+  
 memcached:
   ## Various values that get set as command-line flags.
   ## ref: https://github.com/memcached/memcached/wiki/ConfiguringServer#commandline-arguments
   ##
   maxItemMemory: 64
-  #verbosity: vvv
+  verbosity: v
 
 ## Configure resource requests and limits
 ## ref: http://kubernetes.io/docs/user-guide/compute-resources/