Add PlacementPolicy api

Signed-off-by: Tamal Saha <tamal@appscode.com>

apis/apps/v1/placementpolicy_types.go

@@ -0,0 +1,99 @@
+/*
+Copyright AppsCode Inc. and Contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import (
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// +genclient
+// +genclient:nonNamespaced
+// +genclient:skipVerbs=updateStatus
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+// +kubebuilder:resource:scope=Cluster
+
+// PlacementPolicy represents a set of pods with consistent identities.
+// Identities are defined as:
+//   - Network: A single stable DNS and hostname.
+//   - Storage: As many VolumeClaims as requested.
+//
+// The PlacementPolicy guarantees that a given network identity will always
+// map to the same storage identity.
+type PlacementPolicy struct {
+	metav1.TypeMeta `json:",inline"`
+	// Standard object's metadata.
+	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
+	// +optional
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	// Spec defines the desired identities of pods in this set.
+	// +optional
+	Spec PlacementPolicySpec `json:"spec,omitempty"`
+}
+
+// A PlacementPolicySpec is the specification of a PlacementPolicy.
+type PlacementPolicySpec struct {
+	// +optional
+	ZoneSpreadConstraint *ZoneSpreadConstraint `json:"zoneSpreadConstraint,omitempty"`
+
+	// +optional
+	NodeSpreadConstraint *NodeSpreadConstraint `json:"nodeSpreadConstraint,omitempty"`
+
+	// +optional
+	NodeAffinity []NodeAffinityRules `json:"nodeAffinity,omitempty"`
+}
+
+type ZoneSpreadConstraint struct {
+	Zones             []string                         `json:"zones"`
+	MaxSkew           int32                            `json:"maxSkew"`
+	WhenUnsatisfiable v1.UnsatisfiableConstraintAction `json:"whenUnsatisfiable"`
+}
+
+type NodeSpreadConstraint struct {
+	MaxSkew           int32                            `json:"maxSkew"`
+	WhenUnsatisfiable v1.UnsatisfiableConstraintAction `json:"whenUnsatisfiable"`
+}
+
+type NodeAffinityRules struct {
+	TopologyKey       string                           `json:"topologyKey"`
+	Domains           []TopologyDomain                 `json:"domains"`
+	WhenUnsatisfiable v1.UnsatisfiableConstraintAction `json:"whenUnsatisfiable"`
+}
+
+type TopologyDomain struct {
+	Domain   string `json:"domain"`
+	Replicas string `json:"replicas"`
+}
+
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+// PlacementPolicyList is a collection of PlacementPolicys.
+type PlacementPolicyList struct {
+	metav1.TypeMeta `json:",inline"`
+	// Standard list's metadata.
+	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
+	// +optional
+	metav1.ListMeta `json:"metadata,omitempty"`
+
+	// Items is the list of stateful sets.
+	Items []PlacementPolicy `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&PlacementPolicy{}, &PlacementPolicyList{})
+}