diff --git a/registry/handlers/tags.go b/registry/handlers/tags.go index 72d1dc8f..0cc38102 100644 --- a/registry/handlers/tags.go +++ b/registry/handlers/tags.go @@ -3,6 +3,8 @@ package handlers import ( "encoding/json" "net/http" + "sort" + "strconv" "github.com/distribution/distribution/v3" "github.com/distribution/distribution/v3/registry/api/errcode" @@ -49,6 +51,51 @@ func (th *tagsHandler) GetTags(w http.ResponseWriter, r *http.Request) { return } + // do pagination if requested + q := r.URL.Query() + // get entries after latest, if any specified + if lastEntry := q.Get("last"); lastEntry != "" { + lastEntryIndex := sort.SearchStrings(tags, lastEntry) + + // as`sort.SearchStrings` can return len(tags), if the + // specified `lastEntry` is not found, we need to + // ensure it does not panic when slicing. + if lastEntryIndex == len(tags) { + tags = []string{} + } else { + tags = tags[lastEntryIndex+1:] + } + } + + // if no error, means that the user requested `n` entries + if n := q.Get("n"); n != "" { + maxEntries, err := strconv.Atoi(n) + if err != nil || maxEntries < 0 { + th.Errors = append(th.Errors, v2.ErrorCodePaginationNumberInvalid.WithDetail(map[string]string{"n": n})) + return + } + + // if there is requested more than or + // equal to the amount of tags we have, + // then set the request to equal `len(tags)`. + // the reason for the `=`, is so the else + // clause will only activate if there + // are tags left the user needs. + if maxEntries >= len(tags) { + maxEntries = len(tags) + } else if maxEntries > 0 { + // defined in `catalog.go` + urlStr, err := createLinkEntry(r.URL.String(), maxEntries, tags[maxEntries-1]) + if err != nil { + th.Errors = append(th.Errors, errcode.ErrorCodeUnknown.WithDetail(err)) + return + } + w.Header().Set("Link", urlStr) + } + + tags = tags[:maxEntries] + } + w.Header().Set("Content-Type", "application/json") enc := json.NewEncoder(w) diff --git a/registry/storage/tagstore.go b/registry/storage/tagstore.go index e33bf9da..7bbb2f01 100644 --- a/registry/storage/tagstore.go +++ b/registry/storage/tagstore.go @@ -3,6 +3,7 @@ package storage import ( "context" "path" + "sort" "github.com/distribution/distribution/v3" storagedriver "github.com/distribution/distribution/v3/registry/storage/driver" @@ -47,6 +48,10 @@ func (ts *tagStore) All(ctx context.Context) ([]string, error) { tags = append(tags, filename) } + // there is no guarantee for the order, + // therefore sort before return. + sort.Strings(tags) + return tags, nil }