image-checker/main.go
2025-07-17 02:53:36 +02:00

119 lines
3.1 KiB
Go

package main
import (
"context"
"fmt"
"log"
"os"
"regexp"
"github.com/docker/docker/api/types/container"
"github.com/docker/docker/api/types/image"
"github.com/docker/docker/client"
"github.com/regclient/regclient"
"github.com/regclient/regclient/types/ref"
)
// Zerlegt einen Image-Namen in die Form registry/repo:tag für regclient
func parseImageName(imageName string) (string, error) {
r := regexp.MustCompile(`^(?:(?P<registry>[^/]+)/)?(?P<repo>[^:]+)(?::(?P<tag>.+))?$`)
match := r.FindStringSubmatch(imageName)
if len(match) == 0 {
return "", fmt.Errorf("Fehler beim Parsen des Image-Namens: %s", imageName)
}
registry := match[r.SubexpIndex("registry")]
repo := match[r.SubexpIndex("repo")]
tag := match[r.SubexpIndex("tag")]
if repo == "" {
return "", fmt.Errorf("Kein Repo erkannt in %s", imageName)
}
if registry == "" {
registry = "registry-1.docker.io"
}
if tag == "" {
tag = "latest"
}
return fmt.Sprintf("%s/%s:%s", registry, repo, tag), nil
}
// Digest remote ermitteln (regclient)
func getRemoteDigest(ctx context.Context, rc *regclient.RegClient, image string) (string, error) {
refObj, err := ref.New(image)
if err != nil {
return "", fmt.Errorf("image-ref ungültig: %w", err)
}
desc, err := rc.ManifestHead(ctx, refObj)
if err != nil {
return "", fmt.Errorf("Fehler ManifestHead %s: %w", image, err)
}
return desc.GetDigest().String(), nil
}
// Lokalen Digest via Docker-API holen
func getLocalDigestOfImage(ctx context.Context, cli *client.Client, imageName string) (string, error) {
images, err := cli.ImageList(ctx, image.ListOptions{All: true})
if err != nil {
return "", err
}
for _, img := range images {
for _, t := range img.RepoTags {
if t == imageName {
if len(img.RepoDigests) > 0 {
return img.RepoDigests[0], nil
}
return img.ID, nil
}
}
}
return "", fmt.Errorf("Image %s nicht lokal gefunden", imageName)
}
func main() {
ctx := context.Background()
cli, err := client.NewClientWithOpts(client.FromEnv)
if err != nil {
log.Fatal(err)
}
defer cli.Close()
rc := regclient.New()
containers, err := cli.ContainerList(ctx, container.ListOptions{All: true})
if err != nil {
log.Fatal(err)
}
if len(containers) == 0 {
fmt.Println("Keine laufenden Container gefunden")
os.Exit(0)
}
for _, ctr := range containers {
fmt.Printf("Container: %s %s (status: %s)\n", ctr.ID[:12], ctr.Image, ctr.Status)
imageFull, err := parseImageName(ctr.Image)
if err != nil {
fmt.Printf(" Fehler beim Parsen des Image-Namens: %v\n", err)
continue
}
localDigest, err := getLocalDigestOfImage(ctx, cli, ctr.Image)
if err != nil {
fmt.Printf(" Fehler beim lokalen Digest: %v\n", err)
continue
}
remoteDigest, err := getRemoteDigest(ctx, rc, imageFull)
if err != nil {
fmt.Printf(" Fehler beim Remote-Digest: %v\n", err)
continue
}
fmt.Println(" Local Digest: ", localDigest)
fmt.Println(" Remote Digest:", remoteDigest)
if localDigest == remoteDigest {
fmt.Println(" -> Image ist aktuell")
} else {
fmt.Println(" -> Update verfügbar!\n")
}
}
}