cronjob.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 etcd

import (
	"bytes"
	"fmt"
	"text/template"

	"github.com/Masterminds/sprig"

	kubermaticv1 "github.com/kubermatic/kubermatic/api/pkg/crd/kubermatic/v1"
	"github.com/kubermatic/kubermatic/api/pkg/resources"
	"github.com/kubermatic/kubermatic/api/pkg/resources/reconciling"

	batchv1beta1 "k8s.io/api/batch/v1beta1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

type cronJobCreatorData interface {
	Cluster() *kubermaticv1.Cluster
	ImageRegistry(string) string
	GetClusterRef() metav1.OwnerReference
}

// CronJobCreator returns the func to create/update the etcd defragger cronjob
func CronJobCreator(data cronJobCreatorData) reconciling.NamedCronJobCreatorGetter {
	return func() (string, reconciling.CronJobCreator) {
		return resources.EtcdDefragCronJobName, func(job *batchv1beta1.CronJob) (*batchv1beta1.CronJob, error) {
			command, err := defraggerCommand(data)
			if err != nil {
				return nil, err
			}

			job.Name = resources.EtcdDefragCronJobName
			job.OwnerReferences = []metav1.OwnerReference{data.GetClusterRef()}
			job.Spec.ConcurrencyPolicy = batchv1beta1.ForbidConcurrent
			var historyLimit int32
			job.Spec.SuccessfulJobsHistoryLimit = &historyLimit
			job.Spec.Schedule = "@every 3h"
			job.Spec.JobTemplate.Spec.Template.Spec.RestartPolicy = corev1.RestartPolicyOnFailure
			job.Spec.JobTemplate.Spec.Template.Spec.ImagePullSecrets = []corev1.LocalObjectReference{{Name: resources.ImagePullSecretName}}
			job.Spec.JobTemplate.Spec.Template.Spec.Containers = []corev1.Container{
				{
					Name:    "defragger",
					Image:   data.ImageRegistry(resources.RegistryGCR) + "/etcd-development/etcd:" + ImageTag(data.Cluster()),
					Command: command,
					VolumeMounts: []corev1.VolumeMount{
						{
							Name:      resources.ApiserverEtcdClientCertificateSecretName,
							MountPath: "/etc/etcd/pki/client",
							ReadOnly:  true,
						},
					},
				},
			}

			job.Spec.JobTemplate.Spec.Template.Spec.Volumes = []corev1.Volume{
				{
					Name: resources.ApiserverEtcdClientCertificateSecretName,
					VolumeSource: corev1.VolumeSource{
						Secret: &corev1.SecretVolumeSource{
							SecretName: resources.ApiserverEtcdClientCertificateSecretName,
						},
					},
				},
			}

			return job, nil
		}
	}
}

type defraggerCommandTplData struct {
	ServiceName string
	Namespace   string
	CACertFile  string
	CertFile    string
	KeyFile     string
}

func defraggerCommand(data cronJobCreatorData) ([]string, error) {
	tpl, err := template.New("base").Funcs(sprig.TxtFuncMap()).Parse(defraggerCommandTpl)
	if err != nil {
		return nil, fmt.Errorf("failed to parse etcd command template: %v", err)
	}

	tplData := defraggerCommandTplData{
		ServiceName: resources.EtcdServiceName,
		Namespace:   data.Cluster().Status.NamespaceName,
		CACertFile:  resources.CACertSecretKey,
		CertFile:    resources.ApiserverEtcdClientCertificateCertSecretKey,
		KeyFile:     resources.ApiserverEtcdClientCertificateKeySecretKey,
	}

	buf := bytes.Buffer{}
	if err := tpl.Execute(&buf, tplData); err != nil {
		return nil, err
	}

	return []string{
		"/bin/sh",
		"-ec",
		buf.String(),
	}, nil
}

const (
	defraggerCommandTpl = `etcdctl() {
ETCDCTL_API=3 /usr/local/bin/etcdctl \
  --command-timeout=60s \
  --endpoints https://$1.{{ .ServiceName }}.{{ .Namespace }}.svc.cluster.local.:2379 \
  --cacert /etc/etcd/pki/client/{{ .CACertFile }} \
  --cert /etc/etcd/pki/client/{{ .CertFile }} \
  --key /etc/etcd/pki/client/{{ .KeyFile }} \
  $2
}

for node in etcd-0 etcd-1 etcd-2; do
  etcdctl $node "endpoint health"

  if [ $? -eq 0 ]; then
    echo "Defragmenting $node..."
    etcdctl $node defrag
    sleep 30
  else
    echo "$node is not healthy, skipping defrag."
  fi
done`
)