[backups] Added staggered backups

This PS adds staggered backups possibility by adding anti-affinity rules
to backups cronjobs that can be followed across several namespaces to
decrease load on remote backup destination server making sure that at
every moment in time there is only one backup upload is in progress.

Change-Id: I320c6ce6370b45c602114189819a4225e479f680

charts/etcd/Chart.yaml

@@ -15,4 +15,4 @@
 apiVersion: v1
 description: A chart for a DaemonSet-based etcd deployment.
 name: etcd
-version: 0.1.2
+version: 0.1.3

charts/etcd/templates/cron-job-etcd-backup.yaml

@@ -75,6 +75,7 @@ spec:
     metadata:
       labels:
 {{ tuple $envAll $applicationName "etcd-anchor" | include "helm-toolkit.snippets.kubernetes_metadata_labels" | indent 8 }}
+{{  index $envAll.Values.backup "labels"  | toYaml | indent 8}}
       annotations:
 {{ dict "envAll" $envAll "podName" "etcd-backup" "containerNames" (list "etcd-backup") | include "helm-toolkit.snippets.kubernetes_mandatory_access_control_annotation" | indent 8 }}
     spec:
@@ -83,6 +84,10 @@ spec:
 {{ dict "envAll" $envAll "application" "etcd-backup" | include "helm-toolkit.snippets.kubernetes_pod_security_context" | indent 10 }}
           serviceAccountName: {{ .Values.service.name }}-{{ $serviceAccountName }}
           restartPolicy: OnFailure
+{{- if $envAll.Values.backup.affinity }}
+          affinity:
+{{  index $envAll.Values.backup "affinity"  | toYaml | indent 12}}
+{{- end }}
           nodeSelector:
             {{ .Values.labels.anchor.node_selector_key }}: {{ .Values.labels.anchor.node_selector_value }}
           containers:

charts/etcd/values.yaml

@@ -62,6 +62,24 @@ etcd:
 backup:
   enabled: true
   host_backup_path: /var/backups
+  labels:
+    staggered-backups: enabled
+  affinity:
+    podAntiAffinity:
+      requiredDuringSchedulingIgnoredDuringExecution:
+        - labelSelector:
+            matchExpressions:
+              - key: status.phase
+                operator: NotIn
+                values:
+                  - Running
+              - key: staggered-backups
+                operator: In
+                values:
+                  - enabled
+          namespaces:
+            - openstack
+          topologyKey: kubernetes.io/os
   backup_log_file: /var/log/etcd-backup.log
   no_backup_keep: 10
   etcdctl_dial_timeout: 15s