new overlay variables command

internal/app/wwctl/overlay/root.go

@@ -12,6 +12,7 @@ import (
 	"github.com/warewulf/warewulf/internal/app/wwctl/overlay/list"
 	"github.com/warewulf/warewulf/internal/app/wwctl/overlay/mkdir"
 	"github.com/warewulf/warewulf/internal/app/wwctl/overlay/show"
+	"github.com/warewulf/warewulf/internal/app/wwctl/overlay/variables"
 )
 
 var (
@@ -35,6 +36,7 @@ func init() {
 	baseCmd.AddCommand(imprt.GetCommand())
 	baseCmd.AddCommand(chmod.GetCommand())
 	baseCmd.AddCommand(chown.GetCommand())
+	baseCmd.AddCommand(variables.GetCommand())
 }
 
 // GetRootCommand returns the root cobra.Command for the application.

internal/app/wwctl/overlay/variables/main.go

@@ -0,0 +1,30 @@
+package variables
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/warewulf/warewulf/internal/pkg/overlay"
+	"github.com/warewulf/warewulf/internal/pkg/wwlog"
+)
+
+func CobraRunE(cmd *cobra.Command, args []string) error {
+	overlayName := args[0]
+	filePath := args[1]
+
+	ov, err := overlay.Get(overlayName)
+	if err != nil {
+		wwlog.Error("Failed to get overlay %s: %s", overlayName, err)
+		return err
+	}
+
+	vars := ov.ParseVars(filePath)
+	if vars == nil {
+		return fmt.Errorf("could not parse variables for %s in overlay %s", filePath, overlayName)
+	}
+
+	fmt.Println(strings.Join(vars, "\n"))
+
+	return nil
+}

internal/app/wwctl/overlay/variables/main_test.go

@@ -0,0 +1,100 @@
+package variables
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"path"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/warewulf/warewulf/internal/pkg/testenv"
+	"github.com/warewulf/warewulf/internal/pkg/wwlog"
+)
+
+func Test_Overlay_Variables(t *testing.T) {
+	env := testenv.New(t)
+	defer env.RemoveAll()
+	conf := env.Configure()
+
+	// be quiet
+	wwlog.SetLogFormatter(func(int, *wwlog.LogRecord) string { return "" })
+
+	overlayDir := path.Join(conf.Paths.SiteOverlaydir(), "test-overlay")
+	err := os.MkdirAll(overlayDir, 0755)
+	if err != nil {
+		t.Fatalf("could not create overlay dir: %v", err)
+	}
+
+	templateContent := `
+{{ .Kernel.Tags.foo }}
+{{ .Node.Tags.bar }}
+{{ .Cluster.Tags.baz }}
+`
+	templatePath := path.Join(overlayDir, "test.ww")
+	err = os.WriteFile(templatePath, []byte(templateContent), 0644)
+	if err != nil {
+		t.Fatalf("could not write template file: %v", err)
+	}
+
+	// Redirect stdout
+	old := os.Stdout
+	r, w, _ := os.Pipe()
+	os.Stdout = w
+
+	baseCmd.SetArgs([]string{"test-overlay", "test.ww"})
+	err = baseCmd.Execute()
+	assert.NoError(t, err)
+
+	// Restore stdout
+	w.Close()
+	os.Stdout = old
+
+	var buf bytes.Buffer
+	_, err = io.Copy(&buf, r)
+	if err != nil {
+		t.Fatalf("could not read stdout: %v", err)
+	}
+
+	output := strings.TrimSpace(buf.String())
+	expected := []string{
+		".Kernel.Tags.foo",
+		".Node.Tags.bar",
+		".Cluster.Tags.baz",
+	}
+
+	outputLines := strings.Split(output, "\n")
+	assert.ElementsMatch(t, expected, outputLines)
+}
+
+func Test_Overlay_Variables_No_File(t *testing.T) {
+	env := testenv.New(t)
+	defer env.RemoveAll()
+	conf := env.Configure()
+
+	// be quiet
+	wwlog.SetLogFormatter(func(int, *wwlog.LogRecord) string { return "" })
+	overlayDir := path.Join(conf.Paths.SiteOverlaydir(), "test-overlay")
+	err := os.MkdirAll(overlayDir, 0755)
+	if err != nil {
+		t.Fatalf("could not create overlay dir: %v", err)
+	}
+
+	baseCmd.SetArgs([]string{"test-overlay", "test.ww"})
+	err = baseCmd.Execute()
+	assert.Error(t, err)
+}
+
+func Test_Overlay_Variables_No_Overlay(t *testing.T) {
+	env := testenv.New(t)
+	defer env.RemoveAll()
+	env.Configure()
+
+	// be quiet
+	wwlog.SetLogFormatter(func(int, *wwlog.LogRecord) string { return "" })
+
+	baseCmd.SetArgs([]string{"no-overlay", "test.ww"})
+	err := baseCmd.Execute()
+	assert.Error(t, err)
+}

internal/app/wwctl/overlay/variables/root.go

@@ -0,0 +1,39 @@
+package variables
+
+import (
+	"github.com/spf13/cobra"
+	"github.com/warewulf/warewulf/internal/pkg/overlay"
+)
+
+var (
+	baseCmd = &cobra.Command{
+		Use:     "variables [flags] OVERLAY_NAME FILE_PATH",
+		Short:   "Show variables for a template file in an overlay",
+		Long:    "This command will show the variables for a given template file in a given\n" + "overlay.",
+		Aliases: []string{"vars", "tags"},
+		Args:    cobra.ExactArgs(2),
+		RunE:    CobraRunE,
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) == 0 {
+				return overlay.FindOverlays(), cobra.ShellCompDirectiveNoFileComp
+			} else if len(args) == 1 {
+				ov, err := overlay.Get(args[0])
+				if err != nil {
+					return nil, cobra.ShellCompDirectiveError
+				}
+				files, err := ov.GetFiles()
+				if err != nil {
+					return nil, cobra.ShellCompDirectiveError
+				}
+				return files, cobra.ShellCompDirectiveNoFileComp
+			}
+			return nil, cobra.ShellCompDirectiveNoFileComp
+		},
+	}
+)
+
+// GetCommand returns the root cobra.Command for this application.
+func GetCommand() *cobra.Command {
+	return baseCmd
+}
+