Add PodTemplate to cluster specificaton

This patch adds a new parameter to the CRD named `podTemplate`, containing a
template that is used to create Pods for PostgreSQL instances. This feature is
useful to fine-grain configure things that don't have a direct field in
CRD, like NodeAffinity.

The patch also updates the version of `controllen-gen` we are using the latest version
because the previous one had a bug preventing the generation of CRDs where PodTemplate
is used. More information can be found here:

operator-framework/operator-sdk#3235

Co-authored-by: Leonardo Cecchi <leonardo.cecchi@2ndquadrant.it>
Co-authored-by: Jonathan Gonzalez V <jonathan.gonzalez@2ndquadrant.com>
Co-authored-by: Marco Nenciarini <marco.nenciarini@2ndquadrant.it>
Co-authored-by: Gabriele Bartolini <gabriele.bartolini@2ndquadrant.it>

Makefile

@@ -126,13 +126,13 @@ apidoc: po-docgen
 .PHONY: controller-gen
 controller-gen:
 # download controller-gen if necessary
-ifneq ($(shell controller-gen --version), Version: v0.3.0)
+ifneq ($(shell controller-gen --version), Version: v0.4.1)
 	@{ \
 	set -e ;\
 	CONTROLLER_GEN_TMP_DIR=$$(mktemp -d) ;\
 	cd $$CONTROLLER_GEN_TMP_DIR ;\
 	go mod init tmp ;\
-	go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.3.0 ;\
+	go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.4.1 ;\
 	rm -rf $$CONTROLLER_GEN_TMP_DIR ;\
 	}
 CONTROLLER_GEN=$(GOBIN)/controller-gen

api/v1alpha1/cluster_types.go

@@ -61,6 +61,38 @@ const (
 	defaultPostgresGID = 26
 )
 
+// MetaSubset contains a subset of the standard object's metadata.
+// TODO: Dissmiss this type if we can in the future
+type MetaSubset struct {
+	// Annotations is an unstructured key value map stored with a resource that may be
+	// set by external tools to store and retrieve arbitrary metadata. They are not
+	// queryable and should be preserved when modifying objects.
+	// More info: http://kubernetes.io/docs/user-guide/annotations
+	// +optional
+	Annotations map[string]string `json:"annotations,omitempty"`
+
+	// Map of string keys and values that can be used to organize and categorize
+	// (scope and select) objects. May match selectors of replication controllers
+	// and services.
+	// More info: http://kubernetes.io/docs/user-guide/labels
+	// +optional
+	Labels map[string]string `json:"labels,omitempty"`
+}
+
+// PodTemplateSpec describes the data a pod should have when created from a template.
+// TODO: Dissmiss this type if we can in the future
+type PodTemplateSpec struct {
+	// Standard object's metadata.
+	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
+	// +optional
+	Meta MetaSubset `json:"metadata,omitempty"`
+
+	// Specification of the desired behavior of the pod.
+	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
+	// +optional
+	Spec corev1.PodSpec `json:"spec,omitempty"`
+}
+
 // ClusterSpec defines the desired state of Cluster
 type ClusterSpec struct {
 	// Description of this PostgreSQL cluster
@@ -122,6 +154,11 @@ type ClusterSpec struct {
 	// +optional
 	Affinity AffinityConfiguration `json:"affinity,omitempty"`
 
+	// This contains a Pod template which is applied when creating
+	// the actual instances
+	// +optional
+	PodTemplate *PodTemplateSpec `json:"podTemplate,omitempty"`
+
 	// Resources requirements of every generated Pod. Please refer to
 	// https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
 	// for more information.

api/v1alpha1/cluster_webhook.go

@@ -35,7 +35,7 @@ func (r *Cluster) SetupWebhookWithManager(mgr ctrl.Manager) error {
 		Complete()
 }
 
-// +kubebuilder:webhook:path=/mutate-postgresql-k8s-enterprisedb-io-v1alpha1-cluster,mutating=true,failurePolicy=fail,groups=postgresql.k8s.enterprisedb.io,resources=clusters,verbs=create;update,versions=v1alpha1,name=mcluster.kb.io
+// +kubebuilder:webhook:webhookVersions={v1beta1},admissionReviewVersions={v1beta1},path=/mutate-postgresql-k8s-enterprisedb-io-v1alpha1-cluster,mutating=true,failurePolicy=fail,groups=postgresql.k8s.enterprisedb.io,resources=clusters,verbs=create;update,versions=v1alpha1,name=mcluster.kb.io
 
 var _ webhook.Defaulter = &Cluster{}
 
@@ -81,7 +81,7 @@ func (r *Cluster) Default() {
 }
 
 // TODO(user): change verbs to "verbs=create;update;delete" if you want to enable deletion validation.
-// +kubebuilder:webhook:verbs=create;update,path=/validate-postgresql-k8s-enterprisedb-io-v1alpha1-cluster,mutating=false,failurePolicy=fail,groups=postgresql.k8s.enterprisedb.io,resources=clusters,versions=v1alpha1,name=vcluster.kb.io
+// +kubebuilder:webhook:webhookVersions={v1beta1},admissionReviewVersions={v1beta1},verbs=create;update,path=/validate-postgresql-k8s-enterprisedb-io-v1alpha1-cluster,mutating=false,failurePolicy=fail,groups=postgresql.k8s.enterprisedb.io,resources=clusters,versions=v1alpha1,name=vcluster.kb.io
 
 var _ webhook.Validator = &Cluster{}