Add volume selector (#1385)

* Add volume selector
* Add slightly better documentation and gofmt changes
* Update generated deepcopy
* Add test for PV selector

Co-authored-by: John Rood <j.rood@picturae.com>

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

@@ -841,6 +841,54 @@ var PostgresCRDResourceValidation = apiextv1.CustomResourceValidation{
 							"iops": {
 								Type: "integer",
 							},
+							"selector": {
+								Type: "object",
+								Properties: map[string]apiextv1.JSONSchemaProps{
+									"matchExpressions": {
+										Type: "array",
+										Items: &apiextv1.JSONSchemaPropsOrArray{
+											Schema: &apiextv1.JSONSchemaProps{
+												Type:     "object",
+												Required: []string{"key", "operator", "values"},
+												Properties: map[string]apiextv1.JSONSchemaProps{
+													"key": {
+														Type: "string",
+													},
+													"operator": {
+														Type: "string",
+														Enum: []apiextv1.JSON{
+															{
+																Raw: []byte(`"In"`),
+															},
+															{
+																Raw: []byte(`"NotIn"`),
+															},
+															{
+																Raw: []byte(`"Exists"`),
+															},
+															{
+																Raw: []byte(`"DoesNotExist"`),
+															},
+														},
+													},
+													"values": {
+														Type: "array",
+														Items: &apiextv1.JSONSchemaPropsOrArray{
+															Schema: &apiextv1.JSONSchemaProps{
+																Type: "string",
+															},
+														},
+													},
+												},
+											},
+										},
+									},
+									"matchLabels": {
+										Type:                   "object",
+										XPreserveUnknownFields: util.True(),
+									},
+								},
+							},
 							"size": {
 								Type:        "string",
 								Description: "Value must not be zero",

pkg/apis/acid.zalan.do/v1/postgresql_type.go

@@ -114,12 +114,13 @@ type MaintenanceWindow struct {
 
 // Volume describes a single volume in the manifest.
 type Volume struct {
-	Size         string `json:"size"`
-	StorageClass string `json:"storageClass,omitempty"`
-	SubPath      string `json:"subPath,omitempty"`
-	Iops         *int64 `json:"iops,omitempty"`
-	Throughput   *int64 `json:"throughput,omitempty"`
-	VolumeType   string `json:"type,omitempty"`
+	Selector     *metav1.LabelSelector `json:"selector,omitempty"`
+	Size         string                `json:"size"`
+	StorageClass string                `json:"storageClass,omitempty"`
+	SubPath      string                `json:"subPath,omitempty"`
+	Iops         *int64                `json:"iops,omitempty"`
+	Throughput   *int64                `json:"throughput,omitempty"`
+	VolumeType   string                `json:"type,omitempty"`
 }
 
 // AdditionalVolume specs additional optional volumes for statefulset

pkg/apis/acid.zalan.do/v1/zz_generated.deepcopy.go

@@ -29,6 +29,7 @@ package v1
 import (
 	config "github.com/zalando/postgres-operator/pkg/util/config"
 	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	runtime "k8s.io/apimachinery/pkg/runtime"
 )
 
@@ -314,22 +315,6 @@ func (in *MaintenanceWindow) DeepCopy() *MaintenanceWindow {
 	return out
 }
 
-// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
-func (in *MajorVersionUpgradeConfiguration) DeepCopyInto(out *MajorVersionUpgradeConfiguration) {
-	*out = *in
-	return
-}
-
-// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new MajorVersionUpgradeConfiguration.
-func (in *MajorVersionUpgradeConfiguration) DeepCopy() *MajorVersionUpgradeConfiguration {
-	if in == nil {
-		return nil
-	}
-	out := new(MajorVersionUpgradeConfiguration)
-	in.DeepCopyInto(out)
-	return out
-}
-
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OperatorConfiguration) DeepCopyInto(out *OperatorConfiguration) {
 	*out = *in
@@ -385,7 +370,6 @@ func (in *OperatorConfigurationData) DeepCopyInto(out *OperatorConfigurationData
 		}
 	}
 	out.PostgresUsersConfiguration = in.PostgresUsersConfiguration
-	out.MajorVersionUpgrade = in.MajorVersionUpgrade
 	in.Kubernetes.DeepCopyInto(&out.Kubernetes)
 	out.PostgresPodResources = in.PostgresPodResources
 	out.Timeouts = in.Timeouts
@@ -1197,6 +1181,11 @@ func (in UserFlags) DeepCopy() UserFlags {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Volume) DeepCopyInto(out *Volume) {
 	*out = *in
+	if in.Selector != nil {
+		in, out := &in.Selector, &out.Selector
+		*out = new(metav1.LabelSelector)
+		(*in).DeepCopyInto(*out)
+	}
 	if in.Iops != nil {
 		in, out := &in.Iops, &out.Iops
 		*out = new(int64)