wrapper.go

/*
Copyright 2020 The Kubermatic Kubernetes Platform 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 reconciling

import (
	appsv1 "k8s.io/api/apps/v1"
	batchv1beta1 "k8s.io/api/batch/v1beta1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/util/intstr"
	utilpointer "k8s.io/utils/pointer"
)

// OwnerRefWrapper is responsible for wrapping a ObjectCreator function, solely to set the OwnerReference to the cluster object
func OwnerRefWrapper(ref metav1.OwnerReference) ObjectModifier {
	return func(create ObjectCreator) ObjectCreator {
		return func(existing runtime.Object) (runtime.Object, error) {
			obj, err := create(existing)
			if err != nil {
				return obj, err
			}

			obj.(metav1.Object).SetOwnerReferences([]metav1.OwnerReference{ref})
			return obj, nil
		}
	}
}

// DefaultContainer defaults all Container attributes to the same values as they would get from the Kubernetes API
func DefaultContainer(c *corev1.Container, procMountType *corev1.ProcMountType) {
	if c.ImagePullPolicy == "" {
		c.ImagePullPolicy = corev1.PullIfNotPresent
	}
	if c.TerminationMessagePath == "" {
		c.TerminationMessagePath = corev1.TerminationMessagePathDefault
	}
	if c.TerminationMessagePolicy == "" {
		c.TerminationMessagePolicy = corev1.TerminationMessageReadFile
	}

	for idx := range c.Env {
		if c.Env[idx].ValueFrom != nil && c.Env[idx].ValueFrom.FieldRef != nil {
			if c.Env[idx].ValueFrom.FieldRef.APIVersion == "" {
				c.Env[idx].ValueFrom.FieldRef.APIVersion = "v1"
			}
		}
	}

	// This attribut was added in 1.12
	if c.SecurityContext != nil {
		c.SecurityContext.ProcMount = procMountType
	}
}

// DefaultPodSpec defaults all Container attributes to the same values as they would get from the Kubernetes API
func DefaultPodSpec(old, new corev1.PodSpec) (corev1.PodSpec, error) {
	// make sure to keep the old procmount types in case a creator overrides the entire PodSpec
	initContainerProcMountType := map[string]*corev1.ProcMountType{}
	containerProcMountType := map[string]*corev1.ProcMountType{}
	for _, container := range old.InitContainers {
		if container.SecurityContext != nil {
			initContainerProcMountType[container.Name] = container.SecurityContext.ProcMount
		}
	}
	for _, container := range old.Containers {
		if container.SecurityContext != nil {
			containerProcMountType[container.Name] = container.SecurityContext.ProcMount
		}
	}

	for idx, container := range new.InitContainers {
		DefaultContainer(&new.InitContainers[idx], initContainerProcMountType[container.Name])
	}

	for idx, container := range new.Containers {
		DefaultContainer(&new.Containers[idx], containerProcMountType[container.Name])
	}

	for idx, vol := range new.Volumes {
		if vol.VolumeSource.Secret != nil && vol.VolumeSource.Secret.DefaultMode == nil {
			new.Volumes[idx].Secret.DefaultMode = utilpointer.Int32Ptr(corev1.SecretVolumeSourceDefaultMode)
		}
		if vol.VolumeSource.ConfigMap != nil && vol.VolumeSource.ConfigMap.DefaultMode == nil {
			new.Volumes[idx].ConfigMap.DefaultMode = utilpointer.Int32Ptr(corev1.ConfigMapVolumeSourceDefaultMode)
		}
	}

	return new, nil
}

// DefaultDeployment defaults all Deployment attributes to the same values as they would get from the Kubernetes API
func DefaultDeployment(creator DeploymentCreator) DeploymentCreator {
	return func(d *appsv1.Deployment) (*appsv1.Deployment, error) {
		old := d.DeepCopy()

		d, err := creator(d)
		if err != nil {
			return nil, err
		}

		if d.Spec.Strategy.Type == "" {
			d.Spec.Strategy.Type = appsv1.RollingUpdateDeploymentStrategyType

			if d.Spec.Strategy.RollingUpdate == nil {
				d.Spec.Strategy.RollingUpdate = &appsv1.RollingUpdateDeployment{
					MaxSurge: &intstr.IntOrString{
						Type:   intstr.Int,
						IntVal: 1,
					},
					MaxUnavailable: &intstr.IntOrString{
						Type:   intstr.Int,
						IntVal: 0,
					},
				}
			}
		}

		d.Spec.Template.Spec, err = DefaultPodSpec(old.Spec.Template.Spec, d.Spec.Template.Spec)
		if err != nil {
			return nil, err
		}

		return d, nil
	}
}

// DefaultStatefulSet defaults all StatefulSet attributes to the same values as they would get from the Kubernetes API
func DefaultStatefulSet(creator StatefulSetCreator) StatefulSetCreator {
	return func(ss *appsv1.StatefulSet) (*appsv1.StatefulSet, error) {
		old := ss.DeepCopy()

		ss, err := creator(ss)
		if err != nil {
			return nil, err
		}

		ss.Spec.Template.Spec, err = DefaultPodSpec(old.Spec.Template.Spec, ss.Spec.Template.Spec)
		if err != nil {
			return nil, err
		}

		return ss, nil
	}
}

// DefaultDaemonSet defaults all DaemonSet attributes to the same values as they would get from the Kubernetes API
func DefaultDaemonSet(creator DaemonSetCreator) DaemonSetCreator {
	return func(ds *appsv1.DaemonSet) (*appsv1.DaemonSet, error) {
		old := ds.DeepCopy()

		ds, err := creator(ds)
		if err != nil {
			return nil, err
		}

		ds.Spec.Template.Spec, err = DefaultPodSpec(old.Spec.Template.Spec, ds.Spec.Template.Spec)
		if err != nil {
			return nil, err
		}

		return ds, nil
	}
}

// DefaultCronJob defaults all CronJob attributes to the same values as they would get from the Kubernetes API
func DefaultCronJob(creator CronJobCreator) CronJobCreator {
	return func(cj *batchv1beta1.CronJob) (*batchv1beta1.CronJob, error) {
		old := cj.DeepCopy()

		cj, err := creator(cj)
		if err != nil {
			return nil, err
		}

		cj.Spec.JobTemplate.Spec.Template.Spec, err = DefaultPodSpec(old.Spec.JobTemplate.Spec.Template.Spec, cj.Spec.JobTemplate.Spec.Template.Spec)
		if err != nil {
			return nil, err
		}

		return cj, nil
	}
}