Search repository tags using --list-tags

For fix of BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1684263
Add --list-tags to podman search to return a table the repository tags.

Signed-off-by: Qi Wang <qiwan@redhat.com>

cmd/podman/images/search.go

@@ -86,6 +86,7 @@ func searchFlags(flags *pflag.FlagSet) {
 	flags.BoolVar(&searchOptions.NoTrunc, "no-trunc", false, "Do not truncate the output")
 	flags.StringVar(&searchOptions.Authfile, "authfile", auth.GetDefaultAuthFile(), "Path of the authentication file. Use REGISTRY_AUTH_FILE environment variable to override")
 	flags.BoolVar(&searchOptions.TLSVerifyCLI, "tls-verify", true, "Require HTTPS and verify certificates when contacting registries")
+	flags.BoolVar(&searchOptions.ListTags, "list-tags", false, "List the tags of the input registry")
 
 	if registry.IsRemote() {
 		_ = flags.MarkHidden("authfile")
@@ -126,6 +127,19 @@ func imageSearch(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	if searchOptions.ListTags {
+		if len(searchOptions.Filters) != 0 {
+			return errors.Errorf("filters are not applicable to list tags result")
+		}
+		formatStr := "table {{.Name}}\t{{.Tag}}\t"
+		if searchOptions.Format != "" {
+			formatStr = searchOptions.Format
+		}
+		format := genSearchFormat(formatStr)
+		out := formats.StdoutTemplateArray{Output: searchToGeneric(searchReport), Template: format, Fields: searchHeaderMap()}
+		return out.Out()
+	}
+
 	format := genSearchFormat(searchOptions.Format)
 	if len(searchReport) == 0 {
 		return nil

completions/bash/podman

@@ -2024,6 +2024,7 @@ _podman_search() {
 	      --help
 	      -h
 	      --no-trunc
+	      --list-tags
 	"
 	_complete_ "$options_with_args" "$boolean_options"
 }

docs/source/markdown/podman-search.1.md

@@ -56,6 +56,9 @@ Valid placeholders for the Go template are listed below:
 | .Stars          | Star count of image          |
 | .Official       | "[OK]" if image is official  |
 | .Automated      | "[OK]" if image is automated |
+| .Tag            | Repository tag               |
+
+Note: use .Tag only if the --list-tags is set.
 
 **--limit**=*limit*
 
@@ -65,6 +68,12 @@ Example if limit is 10 and two registries are being searched, the total
 number of results will be 20, 10 from each (if there are at least 10 matches in each).
 The order of the search results is the order in which the API endpoint returns the results.
 
+**--list-tags**
+
+List the available tags in the repository for the specified image.
+**Note:** --list-tags requires the search term to be a fully specified image name.
+The result contains the Image name and its tag, one line for every tag associated with the image.
+
 **--no-trunc**
 
 Do not truncate the output
@@ -140,6 +149,15 @@ fedoraproject.org   registry.fedoraproject.org/f25/kubernetes-proxy
 fedoraproject.org   registry.fedoraproject.org/f25/kubernetes-scheduler                          0
 fedoraproject.org   registry.fedoraproject.org/f25/mariadb                                       0
 ```
+
+```
+$ podman search --list-tags  registry.redhat.io/rhel
+NAME                      TAG
+registry.redhat.io/rhel   7.3-74
+registry.redhat.io/rhel   7.6-301
+registry.redhat.io/rhel   7.1-9
+...
+```
 Note: This works only with registries that implement the v2 API. If tried with a v1 registry an error will be returned.
 
 ## FILES

libpod/image/search.go

@@ -2,11 +2,13 @@ package image
 
 import (
 	"context"
+	"fmt"
 	"strconv"
 	"strings"
 	"sync"
 
 	"github.com/containers/image/v5/docker"
+	"github.com/containers/image/v5/transports/alltransports"
 	"github.com/containers/image/v5/types"
 	sysreg "github.com/containers/podman/v2/pkg/registries"
 	"github.com/pkg/errors"
@@ -34,6 +36,8 @@ type SearchResult struct {
 	Official string
 	// Automated indicates if the image was created by an automated build.
 	Automated string
+	// Tag is the image tag
+	Tag string
 }
 
 // SearchOptions are used to control the behaviour of SearchImages.
@@ -49,6 +53,8 @@ type SearchOptions struct {
 	Authfile string
 	// InsecureSkipTLSVerify allows to skip TLS verification.
 	InsecureSkipTLSVerify types.OptionalBool
+	// ListTags returns the search result with available tags
+	ListTags bool
 }
 
 // SearchFilter allows filtering the results of SearchImages.
@@ -147,6 +153,15 @@ func searchImageInRegistry(term string, registry string, options SearchOptions)
 	// every types.SystemContext, and to compute the value just once in one
 	// place.
 	sc.SystemRegistriesConfPath = sysreg.SystemRegistriesConfPath()
+	if options.ListTags {
+		results, err := searchRepositoryTags(registry, term, sc, options)
+		if err != nil {
+			logrus.Errorf("error listing registry tags %q: %v", registry, err)
+			return []SearchResult{}
+		}
+		return results
+	}
+
 	results, err := docker.SearchRegistry(context.TODO(), sc, registry, term, limit)
 	if err != nil {
 		logrus.Errorf("error searching registry %q: %v", registry, err)
@@ -207,6 +222,42 @@ func searchImageInRegistry(term string, registry string, options SearchOptions)
 	return paramsArr
 }
 
+func searchRepositoryTags(registry, term string, sc *types.SystemContext, options SearchOptions) ([]SearchResult, error) {
+	dockerPrefix := fmt.Sprintf("%s://", docker.Transport.Name())
+	imageRef, err := alltransports.ParseImageName(fmt.Sprintf("%s/%s", registry, term))
+	if err == nil && imageRef.Transport().Name() != docker.Transport.Name() {
+		return nil, errors.Errorf("reference %q must be a docker reference", term)
+	} else if err != nil {
+		imageRef, err = alltransports.ParseImageName(fmt.Sprintf("%s%s", dockerPrefix, fmt.Sprintf("%s/%s", registry, term)))
+		if err != nil {
+			return nil, errors.Errorf("reference %q must be a docker reference", term)
+		}
+	}
+	tags, err := docker.GetRepositoryTags(context.TODO(), sc, imageRef)
+	if err != nil {
+		return nil, errors.Errorf("error getting repository tags: %v", err)
+	}
+	limit := maxQueries
+	if len(tags) < limit {
+		limit = len(tags)
+	}
+	if options.Limit != 0 {
+		limit = len(tags)
+		if options.Limit < limit {
+			limit = options.Limit
+		}
+	}
+	paramsArr := []SearchResult{}
+	for i := 0; i < limit; i++ {
+		params := SearchResult{
+			Name: imageRef.DockerReference().Name(),
+			Tag:  tags[i],
+		}
+		paramsArr = append(paramsArr, params)
+	}
+	return paramsArr, nil
+}
+
 // ParseSearchFilter turns the filter into a SearchFilter that can be used for
 // searching images.
 func ParseSearchFilter(filter []string) (*SearchFilter, error) {

pkg/api/handlers/libpod/images.go

@@ -608,6 +608,7 @@ func SearchImages(w http.ResponseWriter, r *http.Request) {
 		NoTrunc   bool     `json:"noTrunc"`
 		Filters   []string `json:"filters"`
 		TLSVerify bool     `json:"tlsVerify"`
+		ListTags  bool     `json:"listTags"`
 	}{
 		// This is where you can override the golang default value for one of fields
 	}
@@ -618,8 +619,9 @@ func SearchImages(w http.ResponseWriter, r *http.Request) {
 	}
 
 	options := image.SearchOptions{
-		Limit:   query.Limit,
-		NoTrunc: query.NoTrunc,
+		Limit:    query.Limit,
+		NoTrunc:  query.NoTrunc,
+		ListTags: query.ListTags,
 	}
 	if _, found := r.URL.Query()["tlsVerify"]; found {
 		options.InsecureSkipTLSVerify = types.NewOptionalBool(!query.TLSVerify)
@@ -650,6 +652,7 @@ func SearchImages(w http.ResponseWriter, r *http.Request) {
 		reports[i].Stars = searchResults[i].Stars
 		reports[i].Official = searchResults[i].Official
 		reports[i].Automated = searchResults[i].Automated
+		reports[i].Tag = searchResults[i].Tag
 	}
 
 	utils.WriteResponse(w, http.StatusOK, reports)

pkg/api/server/register_images.go

@@ -169,6 +169,10 @@ func (s *APIServer) registerImagesHandlers(r *mux.Router) error {
 	//        - `is-automated=(true|false)`
 	//        - `is-official=(true|false)`
 	//        - `stars=<number>` Matches images that has at least 'number' stars.
+	//  - in: query
+	//    name: listTags
+	//    type: boolean
+	//    description: list the available tags in the repository
 	// produces:
 	// - application/json
 	// responses:

pkg/bindings/images/images.go

@@ -314,6 +314,7 @@ func Search(ctx context.Context, term string, opts entities.ImageSearchOptions)
 	params.Set("term", term)
 	params.Set("limit", strconv.Itoa(opts.Limit))
 	params.Set("noTrunc", strconv.FormatBool(opts.NoTrunc))
+	params.Set("listTags", strconv.FormatBool(opts.ListTags))
 	for _, f := range opts.Filters {
 		params.Set("filters", f)
 	}

pkg/domain/entities/images.go

@@ -214,6 +214,8 @@ type ImageSearchOptions struct {
 	NoTrunc bool
 	// SkipTLSVerify to skip  HTTPS and certificate verification.
 	SkipTLSVerify types.OptionalBool
+	// ListTags search the available tags of the repository
+	ListTags bool
 }
 
 // ImageSearchReport is the response from searching images.
@@ -230,6 +232,8 @@ type ImageSearchReport struct {
 	Official string
 	// Automated indicates if the image was created by an automated build.
 	Automated string
+	// Tag is the repository tag
+	Tag string
 }
 
 // Image List Options

pkg/domain/infra/abi/images.go

@@ -511,6 +511,7 @@ func (ir *ImageEngine) Search(ctx context.Context, term string, opts entities.Im
 		Limit:                 opts.Limit,
 		NoTrunc:               opts.NoTrunc,
 		InsecureSkipTLSVerify: opts.SkipTLSVerify,
+		ListTags:              opts.ListTags,
 	}
 
 	searchResults, err := image.SearchImages(term, searchOpts)
@@ -529,6 +530,7 @@ func (ir *ImageEngine) Search(ctx context.Context, term string, opts entities.Im
 		reports[i].Stars = searchResults[i].Stars
 		reports[i].Official = searchResults[i].Official
 		reports[i].Automated = searchResults[i].Automated
+		reports[i].Tag = searchResults[i].Tag
 	}
 
 	return reports, nil

test/e2e/search_test.go

@@ -423,4 +423,24 @@ registries = ['{{.Host}}:{{.Port}}']`
 		Expect(search.ExitCode()).To(Equal(0))
 		Expect(len(search.OutputToStringArray()) > 1).To(BeTrue())
 	})
+
+	It("podman search repository tags", func() {
+		search := podmanTest.Podman([]string{"search", "--list-tags", "--limit", "30", "docker.io/library/alpine"})
+		search.WaitWithDefaultTimeout()
+		Expect(search.ExitCode()).To(Equal(0))
+		Expect(len(search.OutputToStringArray())).To(Equal(31))
+
+		search = podmanTest.Podman([]string{"search", "--list-tags", "docker.io/library/alpine"})
+		search.WaitWithDefaultTimeout()
+		Expect(search.ExitCode()).To(Equal(0))
+		Expect(len(search.OutputToStringArray()) > 2).To(BeTrue())
+
+		search = podmanTest.Podman([]string{"search", "--filter=is-official", "--list-tags", "docker.io/library/alpine"})
+		search.WaitWithDefaultTimeout()
+		Expect(search.ExitCode()).To(Not(Equal(0)))
+
+		search = podmanTest.Podman([]string{"search", "--list-tags", "docker.io/library/"})
+		search.WaitWithDefaultTimeout()
+		Expect(len(search.OutputToStringArray()) == 1).To(BeTrue())
+	})
 })