Adding json formatting to --list-tags option in podman search

command.

Data is formatted following this JSON structure:
```json
{
    "Name": "...",
    "Tags": ["...", "...", "..."]
}
```

Closes: #8740.

Signed-off-by: Alexandre Fourcat <afourcat@gmail.com>

cmd/podman/images/search.go

@@ -149,14 +149,13 @@ func imageSearch(cmd *cobra.Command, args []string) error {
 		if len(searchOptions.Filters) != 0 {
 			return errors.Errorf("filters are not applicable to list tags result")
 		}
+		if report.IsJSON(searchOptions.Format) {
+			listTagsEntries := buildListTagsJson(searchReport)
+			return printJson(listTagsEntries)
+		}
 		row = "{{.Name}}\t{{.Tag}}\n"
 	case report.IsJSON(searchOptions.Format):
-		prettyJSON, err := json.MarshalIndent(searchReport, "", "    ")
-		if err != nil {
-			return err
-		}
-		fmt.Println(string(prettyJSON))
-		return nil
+		return printJson(searchReport)
 	case cmd.Flags().Changed("format"):
 		renderHeaders = parse.HasTable(searchOptions.Format)
 		row = report.NormalizeFormat(searchOptions.Format)
@@ -180,3 +179,39 @@ func imageSearch(cmd *cobra.Command, args []string) error {
 
 	return tmpl.Execute(w, searchReport)
 }
+
+func printJson(v interface{}) error {
+	prettyJSON, err := json.MarshalIndent(v, "", "    ")
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(prettyJSON))
+	return nil
+}
+
+func buildListTagsJson(searchReport []entities.ImageSearchReport) interface{} {
+	entries := []struct {
+		Name string
+		Tags []string
+	}{}
+
+ReportLoop:
+	for _, report := range searchReport {
+		for idx, entry := range entries {
+			if entry.Name == report.Name {
+				entries[idx].Tags = append(entries[idx].Tags, report.Tag)
+				continue ReportLoop
+			}
+		}
+		newElem := struct {
+			Name string
+			Tags []string
+		}{
+			report.Name,
+			[]string{report.Tag},
+		}
+
+		entries = append(entries, newElem)
+	}
+	return entries
+}

test/e2e/search_test.go

@@ -124,6 +124,15 @@ registries = ['{{.Host}}:{{.Port}}']`
 		Expect(search.OutputToString()).To(ContainSubstring("docker.io/library/alpine"))
 	})
 
+	It("podman search format json list tags", func() {
+		search := podmanTest.Podman([]string{"search", "--list-tags", "--format", "json", "alpine"})
+		search.WaitWithDefaultTimeout()
+		Expect(search.ExitCode()).To(Equal(0))
+		Expect(search.IsJSONOutputValid()).To(BeTrue())
+		Expect(search.OutputToString()).To(ContainSubstring("docker.io/library/alpine"))
+		Expect(search.OutputToString()).To(ContainSubstring("3.10"))
+	})
+
 	It("podman search no-trunc flag", func() {
 		search := podmanTest.Podman([]string{"search", "--no-trunc", "alpine"})
 		search.WaitWithDefaultTimeout()