mirror of
https://github.com/edgelesssys/constellation.git
synced 2024-12-30 18:06:14 -05:00
110 lines
2.7 KiB
Go
110 lines
2.7 KiB
Go
/*
|
|
Copyright (c) Edgeless Systems GmbH
|
|
|
|
SPDX-License-Identifier: AGPL-3.0-only
|
|
*/
|
|
|
|
package deploy
|
|
|
|
import (
|
|
"bufio"
|
|
"fmt"
|
|
"regexp"
|
|
"strings"
|
|
|
|
"github.com/spf13/afero"
|
|
)
|
|
|
|
// ImageInfo retrieves OS image information.
|
|
type ImageInfo struct {
|
|
fs *afero.Afero
|
|
}
|
|
|
|
// NewImageInfo creates a new imageInfo.
|
|
func NewImageInfo() *ImageInfo {
|
|
return &ImageInfo{
|
|
fs: &afero.Afero{Fs: afero.NewOsFs()},
|
|
}
|
|
}
|
|
|
|
// ImageVersion tries to parse the image version from the host mounted os-release file.
|
|
// If the file is not present or does not contain the version, a fallback lookup is performed.
|
|
func (i *ImageInfo) ImageVersion() (string, error) {
|
|
var version string
|
|
var err error
|
|
for _, path := range osReleasePaths {
|
|
version, err = i.getOSReleaseImageVersion(path)
|
|
if err == nil {
|
|
break
|
|
}
|
|
}
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
if version == "" {
|
|
return "", fmt.Errorf("IMAGE_VERSION not found in %s", strings.Join(osReleasePaths, ", "))
|
|
}
|
|
return version, nil
|
|
}
|
|
|
|
// getOSReleaseImageVersion reads the os-release file and returns the image version (if present).
|
|
func (i *ImageInfo) getOSReleaseImageVersion(path string) (string, error) {
|
|
osRelease, err := i.fs.Open(path)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
defer osRelease.Close()
|
|
osReleaseMap, err := parseOSRelease(bufio.NewScanner(osRelease))
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
version, ok := osReleaseMap[versionKey]
|
|
if !ok {
|
|
return "", fmt.Errorf("IMAGE_VERSION not found in %s", path)
|
|
}
|
|
return version, nil
|
|
}
|
|
|
|
// parseOSRelease parses the os-release file and returns a map of key-value pairs.
|
|
// The os-release file is a simple key-value file.
|
|
// The format is specified in https://www.freedesktop.org/software/systemd/man/os-release.html.
|
|
func parseOSRelease(osRelease *bufio.Scanner) (map[string]string, error) {
|
|
osReleaseMap := make(map[string]string)
|
|
for osRelease.Scan() {
|
|
line := osRelease.Text()
|
|
matches := osReleaseLine.FindStringSubmatch(line)
|
|
if len(matches) < 6 {
|
|
continue
|
|
}
|
|
key := matches[1]
|
|
var value string
|
|
// group 3 is the value with double quotes
|
|
// group 4 is the value with single quotes
|
|
// group 5 is the value without quotes
|
|
for i := 3; i < 6; i++ {
|
|
if matches[i] != "" {
|
|
value = matches[i]
|
|
break
|
|
}
|
|
}
|
|
// unescape the following characters: \\, \$, \", \', \`
|
|
value = osReleaseUnescape.ReplaceAllString(value, "$1")
|
|
osReleaseMap[key] = value
|
|
}
|
|
if err := osRelease.Err(); err != nil {
|
|
return nil, err
|
|
}
|
|
return osReleaseMap, nil
|
|
}
|
|
|
|
const versionKey = "IMAGE_VERSION"
|
|
|
|
var (
|
|
osReleaseLine = regexp.MustCompile(`^(?P<name>[a-zA-Z0-9_]+)=("(?P<v1>.*)"|'(?P<v2>.*)'|(?P<v3>[^\n"']+))$`)
|
|
osReleaseUnescape = regexp.MustCompile(`\\([\\\$\"\'` + "`" + `])`)
|
|
osReleasePaths = []string{
|
|
"/host/etc/os-release",
|
|
"/host/usr/lib/os-release",
|
|
}
|
|
)
|