39 lines
965 B
Go
39 lines
965 B
Go
package registry
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import (
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"fmt"
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"net/http"
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"github.com/docker/distribution/manifest/schema2"
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digest "github.com/opencontainers/go-digest"
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)
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// Digest returns the digest for an image.
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func (r *Registry) Digest(image Image) (digest.Digest, error) {
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if len(image.Digest) > 1 {
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// return early if we already have an image digest.
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return image.Digest, nil
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}
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url := r.url("/v2/%s/manifests/%s", image.Path, image.Tag)
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r.Logf("registry.manifests.get url=%s repository=%s ref=%s",
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url, image.Path, image.Tag)
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req, err := http.NewRequest("GET", url, nil)
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if err != nil {
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return "", err
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}
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req.Header.Add("Accept", schema2.MediaTypeManifest)
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resp, err := r.Client.Do(req)
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if err != nil {
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return "", err
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}
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defer resp.Body.Close()
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if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNotFound {
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return "", fmt.Errorf("Got status code: %d", resp.StatusCode)
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}
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return digest.Parse(resp.Header.Get("Docker-Content-Digest"))
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}
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