talos

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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this
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// file, You can obtain one at http://mozilla.org/MPL/2.0/.
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package kubernetes
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import (
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	"context"
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	"errors"
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	"fmt"
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	"strings"
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	"github.com/blang/semver/v4"
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	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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)
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// DetectLowestVersion returns lowest Kubernetes components versions in the cluster.
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//
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//nolint:gocyclo
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func DetectLowestVersion(ctx context.Context, cluster UpgradeProvider, options UpgradeOptions) (string, error) {
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	k8sClient, err := cluster.K8sHelper(ctx)
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	if err != nil {
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		return "", fmt.Errorf("error building kubernetes client: %w", err)
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	}
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	apps := map[string]struct{}{
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		"kube-apiserver":          {},
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		"kube-controller-manager": {},
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		"kube-proxy":              {},
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		"kube-scheduler":          {},
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	}
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	pods, err := k8sClient.CoreV1().Pods("kube-system").List(ctx, metav1.ListOptions{})
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	if err != nil {
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		return "", err
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	}
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	var version *semver.Version
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	for _, pod := range pods.Items {
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		app := pod.GetObjectMeta().GetLabels()["k8s-app"]
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		if _, ok := apps[app]; !ok {
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			continue
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		}
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		for _, container := range pod.Spec.Containers {
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			if container.Name != app {
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				continue
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			}
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			idx := strings.LastIndex(container.Image, ":")
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			if idx == -1 {
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				continue
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			}
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			v, err := semver.ParseTolerant(strings.TrimLeft(container.Image[idx+1:], "v"))
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			if err != nil {
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				options.Log("failed to parse %s container version %s", app, err)
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				continue
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			}
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			if version == nil || v.LT(*version) {
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				version = &v
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			}
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		}
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	}
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	if version == nil {
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		return "", errors.New("failed to detect lowest Kubernetes version")
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	}
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	return version.String(), nil
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}
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