1 files changed, 141 insertions, 0 deletions
diff --git a/pkg/v1/remote/list.go b/pkg/v1/remote/list.go
new file mode 100644
index 0000000..e643c49
--- /dev/null
+++ b/pkg/v1/remote/list.go
@@ -0,0 +1,141 @@
+// Copyright 2018 Google LLC All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package remote
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/google/go-containerregistry/pkg/name"
+	"github.com/google/go-containerregistry/pkg/v1/remote/transport"
+)
+
+type tags struct {
+	Name string   `json:"name"`
+	Tags []string `json:"tags"`
+}
+
+// ListWithContext calls List with the given context.
+//
+// Deprecated: Use List and WithContext. This will be removed in a future release.
+func ListWithContext(ctx context.Context, repo name.Repository, options ...Option) ([]string, error) {
+	return List(repo, append(options, WithContext(ctx))...)
+}
+
+// List calls /tags/list for the given repository, returning the list of tags
+// in the "tags" property.
+func List(repo name.Repository, options ...Option) ([]string, error) {
+	o, err := makeOptions(repo, options...)
+	if err != nil {
+		return nil, err
+	}
+	scopes := []string{repo.Scope(transport.PullScope)}
+	tr, err := transport.NewWithContext(o.context, repo.Registry, o.auth, o.transport, scopes)
+	if err != nil {
+		return nil, err
+	}
+
+	uri := &url.URL{
+		Scheme: repo.Registry.Scheme(),
+		Host:   repo.Registry.RegistryStr(),
+		Path:   fmt.Sprintf("/v2/%s/tags/list", repo.RepositoryStr()),
+	}
+
+	if o.pageSize > 0 {
+		uri.RawQuery = fmt.Sprintf("n=%d", o.pageSize)
+	}
+
+	client := http.Client{Transport: tr}
+	tagList := []string{}
+	parsed := tags{}
+
+	// get responses until there is no next page
+	for {
+		select {
+		case <-o.context.Done():
+			return nil, o.context.Err()
+		default:
+		}
+
+		req, err := http.NewRequestWithContext(o.context, "GET", uri.String(), nil)
+		if err != nil {
+			return nil, err
+		}
+
+		resp, err := client.Do(req)
+		if err != nil {
+			return nil, err
+		}
+
+		if err := transport.CheckError(resp, http.StatusOK); err != nil {
+			return nil, err
+		}
+
+		if err := json.NewDecoder(resp.Body).Decode(&parsed); err != nil {
+			return nil, err
+		}
+
+		if err := resp.Body.Close(); err != nil {
+			return nil, err
+		}
+
+		tagList = append(tagList, parsed.Tags...)
+
+		uri, err = getNextPageURL(resp)
+		if err != nil {
+			return nil, err
+		}
+		// no next page
+		if uri == nil {
+			break
+		}
+	}
+
+	return tagList, nil
+}
+
+// getNextPageURL checks if there is a Link header in a http.Response which
+// contains a link to the next page. If yes it returns the url.URL of the next
+// page otherwise it returns nil.
+func getNextPageURL(resp *http.Response) (*url.URL, error) {
+	link := resp.Header.Get("Link")
+	if link == "" {
+		return nil, nil
+	}
+
+	if link[0] != '<' {
+		return nil, fmt.Errorf("failed to parse link header: missing '<' in: %s", link)
+	}
+
+	end := strings.Index(link, ">")
+	if end == -1 {
+		return nil, fmt.Errorf("failed to parse link header: missing '>' in: %s", link)
+	}
+	link = link[1:end]
+
+	linkURL, err := url.Parse(link)
+	if err != nil {
+		return nil, err
+	}
+	if resp.Request == nil || resp.Request.URL == nil {
+		return nil, nil
+	}
+	linkURL = resp.Request.URL.ResolveReference(linkURL)
+	return linkURL, nil
+}