podtemplate.go

/*
Copyright 2014 The Kubernetes Authors.

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.
*/

// This code is directly lifted from the Kubernetes codebase in order to avoid relying on the k8s.io/kubernetes package.
// For reference:
// https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/controller/controller_utils.go#L466-L495
// https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/controller/controller_utils.go#L539-L562

package lifted

import (
	"fmt"

	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/meta"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/runtime"
)

// +lifted:source=https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/controller/controller_utils.go#L466-L472
func getPodsLabelSet(template *corev1.PodTemplateSpec) labels.Set {
	desiredLabels := make(labels.Set)
	for k, v := range template.Labels {
		desiredLabels[k] = v
	}
	return desiredLabels
}

// +lifted:source=https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/controller/controller_utils.go#L474-L478
func getPodsFinalizers(template *corev1.PodTemplateSpec) []string {
	desiredFinalizers := make([]string, len(template.Finalizers))
	copy(desiredFinalizers, template.Finalizers)
	return desiredFinalizers
}

// +lifted:source=https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/controller/controller_utils.go#L480-L486
func getPodsAnnotationSet(template *corev1.PodTemplateSpec) labels.Set {
	desiredAnnotations := make(labels.Set)
	for k, v := range template.Annotations {
		desiredAnnotations[k] = v
	}
	return desiredAnnotations
}

// +lifted:source=https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/controller/controller_utils.go#L488-L495
func getPodsPrefix(controllerName string) string {
	// use the dash (if the name isn't too long) to make the pod name a bit prettier
	prefix := fmt.Sprintf("%s-", controllerName)
	if len(ValidatePodName(prefix, true)) != 0 {
		prefix = controllerName
	}
	return prefix
}

// +lifted:source=https://github.com/kubernetes/kubernetes/blob/release-1.23/pkg/controller/controller_utils.go#L539-L562
// +lifted:changed

// GetPodFromTemplate generates pod object from a template.
func GetPodFromTemplate(template *corev1.PodTemplateSpec, parentObject runtime.Object, controllerRef *metav1.OwnerReference) (*corev1.Pod, error) {
	desiredLabels := getPodsLabelSet(template)
	desiredFinalizers := getPodsFinalizers(template)
	desiredAnnotations := getPodsAnnotationSet(template)
	accessor, err := meta.Accessor(parentObject)
	if err != nil {
		return nil, fmt.Errorf("parentObject does not have ObjectMeta, %v", err)
	}
	prefix := getPodsPrefix(accessor.GetName())

	pod := &corev1.Pod{
		ObjectMeta: metav1.ObjectMeta{
			Labels:       desiredLabels,
			Annotations:  desiredAnnotations,
			GenerateName: prefix,
			Finalizers:   desiredFinalizers,
			Namespace:    accessor.GetNamespace(),
		},
	}
	if controllerRef != nil {
		pod.OwnerReferences = append(pod.OwnerReferences, *controllerRef)
	}
	pod.Spec = *template.Spec.DeepCopy()
	return pod, nil
}