added an option to omit template names

clab/config/template.go

@@ -30,13 +30,21 @@ type NodeConfig struct {
 func RenderAll(nodes map[string]nodes.Node, links map[int]*types.Link) (map[string]*NodeConfig, error) {
 	res := make(map[string]*NodeConfig)
 
-	if len(TemplateNames) == 0 {
-		return nil, fmt.Errorf("please specify one of more templates with --template-list")
-	}
 	if len(TemplatePaths) == 0 {
 		return nil, fmt.Errorf("please specify one of more paths with --template-path")
 	}
 
+	if len(TemplateNames) == 0 {
+		var err error
+		TemplateNames, err = GetTemplateNamesInDirs(TemplatePaths)
+		if err != nil {
+			return nil, err
+		}
+		if len(TemplateNames) == 0 {
+			return nil, fmt.Errorf("no templates files were found by %s path", TemplatePaths)
+		}
+	}
+
 	tmpl, err := jT.New("", jT.SearchPath(TemplatePaths...))
 	if err != nil {
 		return nil, err
@@ -49,7 +57,7 @@ func RenderAll(nodes map[string]nodes.Node, links map[int]*types.Link) (map[stri
 		}
 
 		for _, baseN := range TemplateNames {
-			tmplN := fmt.Sprintf("%s-%s.tmpl", baseN, vars["role"])
+			tmplN := fmt.Sprintf("%s__%s.tmpl", baseN, vars["role"])
 			data1, err := tmpl.ExecuteTemplate(tmplN, vars)
 			if err != nil {
 				return nil, err

clab/config/utils.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+	"os"
 	"strconv"
 	"strings"
 
@@ -172,4 +173,30 @@ func ipFarEnd(in netaddr.IPPrefix) netaddr.IPPrefix {
 	return netaddr.IPPrefixFrom(n, in.Bits())
 }
 
-// DictString
+// GetTemplateNamesInDirs returns a list of template file names found in a dir p
+// without traversing nested dirs
+// template names are following the pattern <some-name>__<kind>.tmpl
+func GetTemplateNamesInDirs(paths []string) ([]string, error) {
+	var tnames []string
+	for _, p := range paths {
+		files, err := os.ReadDir(p)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, file := range files {
+			if file.IsDir() {
+				continue
+			}
+			var tn string
+			fn := file.Name()
+			if strings.Contains(fn, "__") {
+				tn = strings.Split(fn, "__")[0]
+			}
+
+			tnames = append(tnames, tn)
+		}
+	}
+
+	return tnames, nil
+}