podman volume ls: use report.Formatter over Template

Currently the podman command --format output code uses a mix of
report.Formatter and report.Template.

I patched report.Formatter to correctly handle newlines[1]. Since we
cannot fix this with report.Template we have to migrate all users to
report.Formatter. This ensures consistent behavior for all commands.

This change does not change the output, we can add a new test for the
newline bug when the common PR is vendored in.

Also fixa bug since the table format is expected to print headers as
well.

[1] https://github.com/containers/common/pull/1146

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

2 files changed, 16 insertions, 19 deletions

diff --git a/cmd/podman/volumes/list.go b/cmd/podman/volumes/list.go
index 06118513d..70041834b 100644
--- a/cmd/podman/volumes/list.go
+++ b/cmd/podman/volumes/list.go
@@ -55,7 +55,7 @@ func init() {
 	_ = lsCommand.RegisterFlagCompletionFunc(filterFlagName, common.AutocompleteVolumeFilters)
 
 	formatFlagName := "format"
-	flags.StringVar(&cliOpts.Format, formatFlagName, "{{.Driver}}\t{{.Name}}\n", "Format volume output using Go template")
+	flags.StringVar(&cliOpts.Format, formatFlagName, "{{range .}}{{.Driver}}\t{{.Name}}\n{{end -}}", "Format volume output using Go template")
 	_ = lsCommand.RegisterFlagCompletionFunc(formatFlagName, common.AutocompleteFormat(&entities.VolumeListReport{}))
 
 	flags.Bool("noheading", false, "Do not print headers")
@@ -95,34 +95,28 @@ func outputTemplate(cmd *cobra.Command, responses []*entities.VolumeListReport)
 		"Name": "VOLUME NAME",
 	})
 
-	var row string
+	rpt := report.New(os.Stdout, cmd.Name())
+	defer rpt.Flush()
+
+	var err error
 	switch {
+	case cmd.Flag("format").Changed:
+		rpt, err = rpt.Parse(report.OriginUser, cliOpts.Format)
 	case cliOpts.Quiet:
-		row = "{{.Name}}\n"
-	case cmd.Flags().Changed("format"):
-		row = report.NormalizeFormat(cliOpts.Format)
+		rpt, err = rpt.Parse(report.OriginUser, "{{.Name}}\n")
 	default:
-		row = cmd.Flag("format").Value.String()
+		rpt, err = rpt.Parse(report.OriginPodman, cliOpts.Format)
 	}
-	format := report.EnforceRange(row)
-
-	tmpl, err := report.NewTemplate("list").Parse(format)
-	if err != nil {
-		return err
-	}
-
-	w, err := report.NewWriterDefault(os.Stdout)
 	if err != nil {
 		return err
 	}
-	defer w.Flush()
 
-	if !(noHeading || cliOpts.Quiet || cmd.Flag("format").Changed) {
-		if err := tmpl.Execute(w, headers); err != nil {
+	if (rpt.RenderHeaders) && !noHeading {
+		if err := rpt.Execute(headers); err != nil {
 			return fmt.Errorf("failed to write report column headers: %w", err)
 		}
 	}
-	return tmpl.Execute(w, responses)
+	return rpt.Execute(responses)
 }
 
 func outputJSON(vols []*entities.VolumeListReport) error {
diff --git a/test/e2e/volume_ls_test.go b/test/e2e/volume_ls_test.go
index dcfb13f4e..24ea50b26 100644
--- a/test/e2e/volume_ls_test.go
+++ b/test/e2e/volume_ls_test.go
@@ -75,7 +75,10 @@ var _ = Describe("Podman volume ls", func() {
 		session.WaitWithDefaultTimeout()
 
 		Expect(session).Should(Exit(0))
-		Expect(session.OutputToStringArray()).To(HaveLen(1), session.OutputToString())
+		arr := session.OutputToStringArray()
+		Expect(arr).To(HaveLen(2))
+		Expect(arr[0]).To(ContainSubstring("NAME"))
+		Expect(arr[1]).To(ContainSubstring("myvol"))
 	})
 
 	It("podman ls volume with --filter flag", func() {