i remove image, use hub.ManifestDigest("nginx", "1.14.1")，but in the manifest.go ManifestDigest() resp == nil

[ap6108]

i remove image, use hub.ManifestDigest("nginx", "1.14.1")，
but in the manifest.go ManifestDigest() resp == nil.
sameple is :
digest, err2 := hub.ManifestDigest(requestObject.Name, requestObject.Version)
in the menifest.go 👍
resp, err := registry.Client.Head(url)
fmt.Printf("resp %+v\n", resp)

the resp is nil
how to do it?
thanks!

[kispaljr]

Hi!

Well, the name of the nginx repository should be library/nginx.
Otherwise this works for me:

package main

import (
	"fmt"

	"github.com/heroku/docker-registry-client/registry"
)

func main() {
	url := "https://registry-1.docker.io/"
	username := "" // anonymous
	password := "" // anonymous
	hub, err := registry.New(url, username, password)

	digest, err := hub.ManifestDigest("library/nginx", "1.14.1")
	fmt.Print(digest, err)
}

Please note however that the return value will be the hash of the schema1 manifest. For the schema2 manifest you should use something like the method added in @peragwin's PR: #51

[ap6108]

in v2,docker 17.03, it is also get nil resp. the error is:
ManifestDigest: Head http://192.168.2.39:8082/v2/httpd/manifests/2.4.37: http: non-successful response (status=404 body="")

func (registry *Registry) ManifestV2Digest(repository, reference string) (digest.Digest, error) {
url := registry.url("/v2/%s/manifests/%s", repository, reference)
registry.Logf("registry.manifest.head url=%s repository=%s reference=%s", url, repository, reference)
req, err := http.NewRequest("HEAD", url, nil)
if err != nil {
return "", err
}
req.Header.Set("Accept", schema2.MediaTypeManifest)
resp, err := registry.Client.Do(req)
if resp != nil {
defer resp.Body.Close()
}
if err != nil {
return "", err
}
return digest.Parse(resp.Header.Get("Docker-Content-Digest"))
}
but it fail.

if i do this:
curl -u admin:admin123 --head -XGET -H "Accept: application/vnd.docker.distribution.manifest.v2+json" http://192.168.2.39:8082/v2/httpd/manifests/2.4.37
it is ok.

and how do solved it?

[ap6108]

i solved it. the fuc ManifestV2Digest() modify "HEAD" to "GET"