Add a default function to cwp config file (#415)

* Add a default function to cwp config file

* Fix the template not working with default function

* Fix issues found by hound

* Remove unused files

app/cmd/cwp.go

@@ -4,15 +4,15 @@ import (
 	"encoding/xml"
 	"fmt"
 	"github.com/jenkins-zh/jenkins-cli/app/cmd/common"
+	"github.com/jenkins-zh/jenkins-cli/app/i18n"
+	"github.com/jenkins-zh/jenkins-cli/util"
 	"github.com/mitchellh/go-homedir"
+	"github.com/spf13/cobra"
+	"go.uber.org/zap"
 	"html/template"
 	"io/ioutil"
 	"os"
 	"path"
-
-	"github.com/jenkins-zh/jenkins-cli/app/i18n"
-	"github.com/jenkins-zh/jenkins-cli/util"
-	"github.com/spf13/cobra"
 )
 
 func init() {
@@ -123,12 +123,10 @@ func (o *CWPOptions) Run(cmd *cobra.Command, args []string) (err error) {
 
 		if o.ConfigPath != "" {
 			configPath := o.ConfigPath
-			if o.ValueSet != nil {
-				if configPath, err = RenderTemplate(o.ConfigPath, o.ValueSet); err != nil {
-					return
-				}
-				defer os.RemoveAll(configPath)
+			if configPath, err = RenderTemplate(o.ConfigPath, o.ValueSet); err != nil {
+				return
 			}
+			defer os.RemoveAll(configPath)
 
 			cwpArgs = append(cwpArgs, "-configPath", configPath)
 		}
@@ -146,13 +144,25 @@ func (o *CWPOptions) Run(cmd *cobra.Command, args []string) (err error) {
 }
 
 // RenderTemplate render a go template to a temporary file
-func RenderTemplate(path string, values map[string]string) (result string, err error) {
+func RenderTemplate(filepath string, values map[string]string) (result string, err error) {
 	var t *template.Template
-	if t, err = template.ParseFiles(path); err == nil {
+	tmp := template.New(path.Base(filepath)).Funcs(template.FuncMap{
+		"default": func(arg interface{}, value interface{}) interface{} {
+			if value == nil {
+				return arg
+			}
+			return value
+		},
+	})
+
+	if t, err = tmp.ParseFiles(filepath); err == nil {
+		logger.Debug("parse template done", zap.String("path", filepath))
 		f, _ := ioutil.TempFile("/tmp", ".yaml")
 		err = t.Execute(f, values)
 
 		result = f.Name()
+	} else {
+		logger.Error("error when parsing template file", zap.Error(err))
 	}
 	return
 }