func (h *Host) fetchImage(name types.ACIdentifier, labels types.Labels) (*Image, error) {
if aci, asc, err := fetch.DiscoverACI(discovery.App{Name: name, Labels: labels.ToMap()}); err != nil {
return nil, errors.Trace(err)
} else if aci == nil {
return nil, ErrNotFound
} else {
return h.ImportImage(name, aci, asc)
}
}
// True if all labels in `labels` are present in `candidate` and have
// the same value
func MatchLabels(labels, candidate types.Labels) bool {
if len(labels) == 0 {
return true
}
cmap := candidate.ToMap()
for _, label := range labels {
if v, ok := cmap[label.Name]; !ok || v != label.Value {
return false
}
}
return true
}
// GetACI retrieves the ACI that best matches the provided app name and labels.
// The returned value is the blob store key of the retrieved ACI.
// If there are multiple matching ACIs choose the latest one (defined as the
// last one imported in the store).
// If no version label is requested, ACIs marked as latest in the ACIInfo are
// preferred.
func (s Store) GetACI(name types.ACIdentifier, labels types.Labels) (string, error) {
var curaciinfo *ACIInfo
versionRequested := false
if _, ok := labels.Get("version"); ok {
versionRequested = true
}
var aciinfos []*ACIInfo
err := s.db.Do(func(tx *sql.Tx) error {
var err error
aciinfos, _, err = GetACIInfosWithAppName(tx, name.String())
return err
})
if err != nil {
return "", err
}
nextKey:
for _, aciinfo := range aciinfos {
im, err := s.GetImageManifest(aciinfo.BlobKey)
if err != nil {
return "", fmt.Errorf("error getting image manifest: %v", err)
}
// The image manifest must have all the requested labels
for _, l := range labels {
ok := false
for _, rl := range im.Labels {
if l.Name == rl.Name && l.Value == rl.Value {
ok = true
break
}
}
if !ok {
continue nextKey
}
}
if curaciinfo != nil {
// If no version is requested prefer the acis marked as latest
if !versionRequested {
if !curaciinfo.Latest && aciinfo.Latest {
curaciinfo = aciinfo
continue nextKey
}
if curaciinfo.Latest && !aciinfo.Latest {
continue nextKey
}
}
// If multiple matching image manifests are found, choose the latest imported in the cas.
if aciinfo.ImportTime.After(curaciinfo.ImportTime) {
curaciinfo = aciinfo
}
} else {
curaciinfo = aciinfo
}
}
if curaciinfo != nil {
return curaciinfo.BlobKey, nil
}
return "", fmt.Errorf("aci not found")
}