2 Copyright 2016 The Kubernetes Authors.
4 Licensed under the Apache License, Version 2.0 (the "License");
5 you may not use this file except in compliance with the License.
6 You may obtain a copy of the License at
8 http://www.apache.org/licenses/LICENSE-2.0
10 Unless required by applicable law or agreed to in writing, software
11 distributed under the License is distributed on an "AS IS" BASIS,
12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 See the License for the specific language governing permissions and
14 limitations under the License.
23 apps "k8s.io/api/apps/v1"
24 v1 "k8s.io/api/core/v1"
25 apiequality "k8s.io/apimachinery/pkg/api/equality"
26 metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
27 intstrutil "k8s.io/apimachinery/pkg/util/intstr"
28 appsclient "k8s.io/client-go/kubernetes/typed/apps/v1"
31 // deploymentutil contains a copy of a few functions from Kubernetes controller code to avoid a dependency on k8s.io/kubernetes.
32 // This code is copied from https://github.com/kubernetes/kubernetes/blob/e856613dd5bb00bcfaca6974431151b5c06cbed5/pkg/controller/deployment/util/deployment_util.go
33 // No changes to the code were made other than removing some unused functions
35 // RsListFunc returns the ReplicaSet from the ReplicaSet namespace and the List metav1.ListOptions.
36 type RsListFunc func(string, metav1.ListOptions) ([]*apps.ReplicaSet, error)
38 // ListReplicaSets returns a slice of RSes the given deployment targets.
39 // Note that this does NOT attempt to reconcile ControllerRef (adopt/orphan),
40 // because only the controller itself should do that.
41 // However, it does filter out anything whose ControllerRef doesn't match.
42 func ListReplicaSets(deployment *apps.Deployment, getRSList RsListFunc) ([]*apps.ReplicaSet, error) {
43 // TODO: Right now we list replica sets by their labels. We should list them by selector, i.e. the replica set's selector
44 // should be a superset of the deployment's selector, see https://github.com/kubernetes/kubernetes/issues/19830.
45 namespace := deployment.Namespace
46 selector, err := metav1.LabelSelectorAsSelector(deployment.Spec.Selector)
50 options := metav1.ListOptions{LabelSelector: selector.String()}
51 all, err := getRSList(namespace, options)
55 // Only include those whose ControllerRef matches the Deployment.
56 owned := make([]*apps.ReplicaSet, 0, len(all))
57 for _, rs := range all {
58 if metav1.IsControlledBy(rs, deployment) {
59 owned = append(owned, rs)
65 // ReplicaSetsByCreationTimestamp sorts a list of ReplicaSet by creation timestamp, using their names as a tie breaker.
66 type ReplicaSetsByCreationTimestamp []*apps.ReplicaSet
68 func (o ReplicaSetsByCreationTimestamp) Len() int { return len(o) }
69 func (o ReplicaSetsByCreationTimestamp) Swap(i, j int) { o[i], o[j] = o[j], o[i] }
70 func (o ReplicaSetsByCreationTimestamp) Less(i, j int) bool {
71 if o[i].CreationTimestamp.Equal(&o[j].CreationTimestamp) {
72 return o[i].Name < o[j].Name
74 return o[i].CreationTimestamp.Before(&o[j].CreationTimestamp)
77 // FindNewReplicaSet returns the new RS this given deployment targets (the one with the same pod template).
78 func FindNewReplicaSet(deployment *apps.Deployment, rsList []*apps.ReplicaSet) *apps.ReplicaSet {
79 sort.Sort(ReplicaSetsByCreationTimestamp(rsList))
80 for i := range rsList {
81 if EqualIgnoreHash(&rsList[i].Spec.Template, &deployment.Spec.Template) {
82 // In rare cases, such as after cluster upgrades, Deployment may end up with
83 // having more than one new ReplicaSets that have the same template as its template,
84 // see https://github.com/kubernetes/kubernetes/issues/40415
85 // We deterministically choose the oldest new ReplicaSet.
89 // new ReplicaSet does not exist.
93 // EqualIgnoreHash returns true if two given podTemplateSpec are equal, ignoring the diff in value of Labels[pod-template-hash]
94 // We ignore pod-template-hash because:
95 // 1. The hash result would be different upon podTemplateSpec API changes
96 // (e.g. the addition of a new field will cause the hash code to change)
97 // 2. The deployment template won't have hash labels
98 func EqualIgnoreHash(template1, template2 *v1.PodTemplateSpec) bool {
99 t1Copy := template1.DeepCopy()
100 t2Copy := template2.DeepCopy()
101 // Remove hash labels from template.Labels before comparing
102 delete(t1Copy.Labels, apps.DefaultDeploymentUniqueLabelKey)
103 delete(t2Copy.Labels, apps.DefaultDeploymentUniqueLabelKey)
104 return apiequality.Semantic.DeepEqual(t1Copy, t2Copy)
107 // GetNewReplicaSet returns a replica set that matches the intent of the given deployment; get ReplicaSetList from client interface.
108 // Returns nil if the new replica set doesn't exist yet.
109 func GetNewReplicaSet(deployment *apps.Deployment, c appsclient.AppsV1Interface) (*apps.ReplicaSet, error) {
110 rsList, err := ListReplicaSets(deployment, RsListFromClient(c))
114 return FindNewReplicaSet(deployment, rsList), nil
117 // RsListFromClient returns an rsListFunc that wraps the given client.
118 func RsListFromClient(c appsclient.AppsV1Interface) RsListFunc {
119 return func(namespace string, options metav1.ListOptions) ([]*apps.ReplicaSet, error) {
120 rsList, err := c.ReplicaSets(namespace).List(context.Background(), options)
124 var ret []*apps.ReplicaSet
125 for i := range rsList.Items {
126 ret = append(ret, &rsList.Items[i])
132 // IsRollingUpdate returns true if the strategy type is a rolling update.
133 func IsRollingUpdate(deployment *apps.Deployment) bool {
134 return deployment.Spec.Strategy.Type == apps.RollingUpdateDeploymentStrategyType
137 // MaxUnavailable returns the maximum unavailable pods a rolling deployment can take.
138 func MaxUnavailable(deployment apps.Deployment) int32 {
139 if !IsRollingUpdate(&deployment) || *(deployment.Spec.Replicas) == 0 {
142 // Error caught by validation
143 _, maxUnavailable, _ := ResolveFenceposts(deployment.Spec.Strategy.RollingUpdate.MaxSurge, deployment.Spec.Strategy.RollingUpdate.MaxUnavailable, *(deployment.Spec.Replicas))
144 if maxUnavailable > *deployment.Spec.Replicas {
145 return *deployment.Spec.Replicas
147 return maxUnavailable
150 // ResolveFenceposts resolves both maxSurge and maxUnavailable. This needs to happen in one
151 // step. For example:
153 // 2 desired, max unavailable 1%, surge 0% - should scale old(-1), then new(+1), then old(-1), then new(+1)
154 // 1 desired, max unavailable 1%, surge 0% - should scale old(-1), then new(+1)
155 // 2 desired, max unavailable 25%, surge 1% - should scale new(+1), then old(-1), then new(+1), then old(-1)
156 // 1 desired, max unavailable 25%, surge 1% - should scale new(+1), then old(-1)
157 // 2 desired, max unavailable 0%, surge 1% - should scale new(+1), then old(-1), then new(+1), then old(-1)
158 // 1 desired, max unavailable 0%, surge 1% - should scale new(+1), then old(-1)
159 func ResolveFenceposts(maxSurge, maxUnavailable *intstrutil.IntOrString, desired int32) (int32, int32, error) {
160 surge, err := intstrutil.GetValueFromIntOrPercent(intstrutil.ValueOrDefault(maxSurge, intstrutil.FromInt(0)), int(desired), true)
164 unavailable, err := intstrutil.GetValueFromIntOrPercent(intstrutil.ValueOrDefault(maxUnavailable, intstrutil.FromInt(0)), int(desired), false)
169 if surge == 0 && unavailable == 0 {
170 // Validation should never allow the user to explicitly use zero values for both maxSurge
171 // maxUnavailable. Due to rounding down maxUnavailable though, it may resolve to zero.
172 // If both fenceposts resolve to zero, then we should set maxUnavailable to 1 on the
173 // theory that surge might not work due to quota.
177 return int32(surge), int32(unavailable), nil