Resize volume by changing pvc size if enabled in config. (#958)

* Try to resize pvc if resizing pv has failed

* added config option to switch between storage resize strategies

* changes according to requests

* Update pkg/controller/operator_config.go

Co-authored-by: Felix Kunde <felix-kunde@gmx.de>

* enable_storage_resize documented

added examples to the default configuration and helm value files

* enable_storage_resize renamed to volume_resize_mode, off by default

* volume_resize_mode renamed to storage_resize_mode

* Update pkg/apis/acid.zalan.do/v1/crds.go

* pkg/cluster/volumes.go updated

* Update docs/reference/operator_parameters.md

* Update manifests/postgresql-operator-default-configuration.yaml

* Update pkg/controller/operator_config.go

* Update pkg/util/config/config.go

* Update charts/postgres-operator/values-crd.yaml

* Update charts/postgres-operator/values.yaml

* Update docs/reference/operator_parameters.md

* added logging if no changes required

Co-authored-by: Felix Kunde <felix-kunde@gmx.de>

charts/postgres-operator/values-crd.yaml

@@ -124,6 +124,8 @@ configKubernetes:
 
   # whether the Spilo container should run in privileged mode
   spilo_privileged: false
+  # storage resize strategy, available options are: ebs, pvc, off
+  storage_resize_mode: ebs
   # operator watches for postgres objects in the given namespace
   watched_namespace: "*"  # listen to all namespaces
 

charts/postgres-operator/values.yaml

@@ -115,6 +115,8 @@ configKubernetes:
 
   # whether the Spilo container should run in privileged mode
   spilo_privileged: "false"
+  # storage resize strategy, available options are: ebs, pvc, off
+  storage_resize_mode: ebs
   # operator watches for postgres objects in the given namespace
   watched_namespace: "*"  # listen to all namespaces