0bdfe05cf2
Kubeadm no longer supports kube-dns and CoreDNS is the only supported DNS server. Remove ClusterConfiguration.DNS.Type from v1beta3 that is used to set the DNS server type.
117 lines
4.0 KiB
Go
117 lines
4.0 KiB
Go
/*
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Copyright 2019 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package upgrade
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import (
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"fmt"
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"os"
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"strings"
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"github.com/coredns/corefile-migration/migration"
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"github.com/pkg/errors"
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"k8s.io/apimachinery/pkg/util/sets"
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clientset "k8s.io/client-go/kubernetes"
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"k8s.io/klog/v2"
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kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
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"k8s.io/kubernetes/cmd/kubeadm/app/phases/addons/dns"
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"k8s.io/kubernetes/cmd/kubeadm/app/preflight"
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)
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// CoreDNSCheck validates installed kubelet version
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type CoreDNSCheck struct {
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name string
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client clientset.Interface
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f func(clientset.Interface) error
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}
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// Name is part of the preflight.Checker interface
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func (c CoreDNSCheck) Name() string {
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return c.name
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}
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// Check is part of the preflight.Checker interface
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func (c CoreDNSCheck) Check() (warnings, errors []error) {
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if err := c.f(c.client); err != nil {
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return nil, []error{err}
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}
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return nil, nil
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}
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// RunCoreDNSMigrationCheck initializes checks related to CoreDNS migration.
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func RunCoreDNSMigrationCheck(client clientset.Interface, ignorePreflightErrors sets.String) error {
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migrationChecks := []preflight.Checker{
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&CoreDNSCheck{
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name: "CoreDNSUnsupportedPlugins",
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client: client,
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f: checkUnsupportedPlugins,
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},
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&CoreDNSCheck{
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name: "CoreDNSMigration",
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client: client,
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f: checkMigration,
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},
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}
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return preflight.RunChecks(migrationChecks, os.Stderr, ignorePreflightErrors)
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}
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// checkUnsupportedPlugins checks if there are any plugins included in the current configuration
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// that are unsupported for migration.
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func checkUnsupportedPlugins(client clientset.Interface) error {
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klog.V(1).Infoln("validating if there are any unsupported CoreDNS plugins in the Corefile")
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_, corefile, currentInstalledCoreDNSversion, err := dns.GetCoreDNSInfo(client)
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if err != nil {
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return err
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}
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currentInstalledCoreDNSversion = strings.TrimLeft(currentInstalledCoreDNSversion, "v")
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unsupportedCoreDNS, err := migration.Unsupported(currentInstalledCoreDNSversion, currentInstalledCoreDNSversion, corefile)
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if err != nil {
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return err
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}
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if len(unsupportedCoreDNS) != 0 {
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var UnsupportedPlugins []string
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for _, unsup := range unsupportedCoreDNS {
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UnsupportedPlugins = append(UnsupportedPlugins, unsup.ToString())
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}
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fmt.Println("[preflight] The corefile contains plugins that kubeadm/CoreDNS does not know how to migrate. " +
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"Each plugin listed should be manually verified for compatibility with the newer version of CoreDNS. " +
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"Once ready, the upgrade can be initiated by skipping the preflight check. During the upgrade, " +
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"kubeadm will migrate the configuration while leaving the listed plugin configs untouched, " +
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"but cannot guarantee that they will work with the newer version of CoreDNS.")
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return errors.Errorf("CoreDNS cannot migrate the following plugins:\n%s", UnsupportedPlugins)
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}
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return nil
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}
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// checkMigration validates if migration of the current CoreDNS ConfigMap is possible.
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func checkMigration(client clientset.Interface) error {
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klog.V(1).Infoln("validating if migration can be done for the current CoreDNS release.")
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_, corefile, currentInstalledCoreDNSversion, err := dns.GetCoreDNSInfo(client)
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if err != nil {
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return err
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}
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currentInstalledCoreDNSversion = strings.TrimLeft(currentInstalledCoreDNSversion, "v")
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_, err = migration.Migrate(currentInstalledCoreDNSversion, strings.TrimLeft(kubeadmconstants.CoreDNSVersion, "v"), corefile, false)
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if err != nil {
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return errors.Wrap(err, "CoreDNS will not be upgraded")
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}
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return nil
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}
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