Merge pull request #14199 from nikhiljindal/deploymentDescribe

Adding a DeploymentDescriber to kubectl

pkg/util/deployment/deployment.go

@@ -0,0 +1,109 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 deployment
+
+import (
+	"fmt"
+	"hash/adler32"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/apis/experimental"
+	client "k8s.io/kubernetes/pkg/client/unversioned"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/labels"
+	"k8s.io/kubernetes/pkg/util"
+)
+
+// Returns the old RCs targetted by the given Deployment.
+func GetOldRCs(deployment experimental.Deployment, c client.Interface) ([]*api.ReplicationController, error) {
+	namespace := deployment.ObjectMeta.Namespace
+	// 1. Find all pods whose labels match deployment.Spec.Selector
+	podList, err := c.Pods(namespace).List(labels.SelectorFromSet(deployment.Spec.Selector), fields.Everything())
+	if err != nil {
+		return nil, fmt.Errorf("error listing pods: %v", err)
+	}
+	// 2. Find the corresponding RCs for pods in podList.
+	// TODO: Right now we list all RCs and then filter. We should add an API for this.
+	oldRCs := map[string]api.ReplicationController{}
+	rcList, err := c.ReplicationControllers(namespace).List(labels.Everything())
+	if err != nil {
+		return nil, fmt.Errorf("error listing replication controllers: %v", err)
+	}
+	for _, pod := range podList.Items {
+		podLabelsSelector := labels.Set(pod.ObjectMeta.Labels)
+		for _, rc := range rcList.Items {
+			rcLabelsSelector := labels.SelectorFromSet(rc.Spec.Selector)
+			if rcLabelsSelector.Matches(podLabelsSelector) {
+				// Filter out RC that has the same pod template spec as the deployment - that is the new RC.
+				if api.Semantic.DeepEqual(rc.Spec.Template, GetNewRCTemplate(deployment)) {
+					continue
+				}
+				oldRCs[rc.ObjectMeta.Name] = rc
+			}
+		}
+	}
+	requiredRCs := []*api.ReplicationController{}
+	for _, value := range oldRCs {
+		requiredRCs = append(requiredRCs, &value)
+	}
+	return requiredRCs, nil
+}
+
+// Returns an RC that matches the intent of the given deployment.
+// Returns nil if the new RC doesnt exist yet.
+func GetNewRC(deployment experimental.Deployment, c client.Interface) (*api.ReplicationController, error) {
+	namespace := deployment.ObjectMeta.Namespace
+	rcList, err := c.ReplicationControllers(namespace).List(labels.Everything())
+	if err != nil {
+		return nil, fmt.Errorf("error listing replication controllers: %v", err)
+	}
+	newRCTemplate := GetNewRCTemplate(deployment)
+
+	for _, rc := range rcList.Items {
+		if api.Semantic.DeepEqual(rc.Spec.Template, newRCTemplate) {
+			// This is the new RC.
+			return &rc, nil
+		}
+	}
+	// new RC does not exist.
+	return nil, nil
+}
+
+// Returns the desired PodTemplateSpec for the new RC corresponding to the given RC.
+func GetNewRCTemplate(deployment experimental.Deployment) *api.PodTemplateSpec {
+	// newRC will have the same template as in deployment spec, plus a unique label in some cases.
+	newRCTemplate := &api.PodTemplateSpec{
+		ObjectMeta: deployment.Spec.Template.ObjectMeta,
+		Spec:       deployment.Spec.Template.Spec,
+	}
+	podTemplateSpecHash := GetPodTemplateSpecHash(newRCTemplate)
+	if deployment.Spec.UniqueLabelKey != "" {
+		newLabels := map[string]string{}
+		for key, value := range deployment.Spec.Template.ObjectMeta.Labels {
+			newLabels[key] = value
+		}
+		newLabels[deployment.Spec.UniqueLabelKey] = fmt.Sprintf("%d", podTemplateSpecHash)
+		newRCTemplate.ObjectMeta.Labels = newLabels
+	}
+	return newRCTemplate
+}
+
+func GetPodTemplateSpecHash(template *api.PodTemplateSpec) uint32 {
+	podTemplateSpecHasher := adler32.New()
+	util.DeepHashObject(podTemplateSpecHasher, template)
+	return podTemplateSpecHasher.Sum32()
+}