add support for global maintenance windows (#3038)

* add support for global maintenance windows
* fix schema validation and trim \ when unmarshalling maintenance window

charts/postgres-operator/crds/operatorconfigurations.yaml

@@ -101,6 +101,11 @@ spec:
               kubernetes_use_configmaps:
                 type: boolean
                 default: false
+              maintenance_windows:
+                items:
+                  pattern: '^\ *((Mon|Tue|Wed|Thu|Fri|Sat|Sun):(2[0-3]|[01]?\d):([0-5]?\d)|(2[0-3]|[01]?\d):([0-5]?\d))-((2[0-3]|[01]?\d):([0-5]?\d)|(2[0-3]|[01]?\d):([0-5]?\d))\ *$'
+                  type: string
+                type: array
               max_instances:
                 type: integer
                 description: "-1 = disabled"

charts/postgres-operator/values.yaml

@@ -49,6 +49,10 @@ configGeneral:
   # Select if setup uses endpoints (default), or configmaps to manage leader (DCS=k8s)
   # kubernetes_use_configmaps: false
 
+  # maintenance windows applied to all Postgres clusters unless overridden in the manifest
+  # maintenance_windows:
+  # - "Sun:01:00-06:00"
+
   # min number of instances in Postgres cluster. -1 = no limit
   min_instances: -1
   # max number of instances in Postgres cluster. -1 = no limit