pkg/kernel/kernel.go

/*
Copyright 2025 Google Inc.

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.
*/

// Note: This file was copied from "k8s.io/kubernetes/pkg/util/kernel".
// This is done so we can avoid marking the entire "k8s.io/kubernetes"
// module as a dependency, hence avoiding frequent CVE-related updates.

package kernel

import (
	"fmt"
	"os"
	"strings"

	"k8s.io/apimachinery/pkg/util/version"
)

type readFileFunc func(string) ([]byte, error)

// GetVersion returns currently running kernel version.
func GetVersion() (*version.Version, error) {
	return getVersion(os.ReadFile)
}

// getVersion reads os release file from the give readFile function.
func getVersion(readFile readFileFunc) (*version.Version, error) {
	kernelVersionFile := "/proc/sys/kernel/osrelease"
	fileContent, err := readFile(kernelVersionFile)
	if err != nil {
		return nil, fmt.Errorf("failed to read os-release file: %s", err.Error())
	}

	kernelVersion, err := version.ParseGeneric(strings.TrimSpace(string(fileContent)))
	if err != nil {
		return nil, fmt.Errorf("failed to parse kernel version: %s", err.Error())
	}

	return kernelVersion, nil
}