fix: improve generate command

Signed-off-by: Alessio Greggi <[email protected]>

cmd/generate_systemd.go

@@ -42,7 +42,7 @@ var generateSystemdCmd = &cobra.Command{
 		}
 		err = template.GenerateTemplate(systemd, outputFile)
 		if err != nil {
-			fmt.Println(err)
+			fmt.Printf("error generating templated file: %v\n", err)
 			os.Exit(1)
 		}
 	},
@@ -52,6 +52,6 @@ func init() {
 	generateCmd.AddCommand(generateSystemdCmd)
 
 	generateSystemdCmd.Flags().StringVarP(&installationPath, "installation-path", "p", "/usr/local/bin", "fwdctl installation path")
-	generateSystemdCmd.Flags().StringVarP(&c.RulesFile, "file", "f", "rules.yml", "rules file")
+	generateSystemdCmd.Flags().StringVarP(&c.RulesFile, "file", "f", "rules.yml", "rules file path")
 	generateSystemdCmd.Flags().StringVarP(&serviceType, "type", "t", "oneshot", "systemd service type [oneshot, fork]")
 }

pkg/template/systemd_template/systemd_service.go

@@ -2,7 +2,9 @@ package systemd_template
 
 import (
 	_ "embed"
+	"errors"
 	"fmt"
+	"os"
 	"path/filepath"
 )
 
@@ -28,15 +30,23 @@ func serviceTypeAllowed(st string) bool {
 }
 
 func NewSystemdService(serviceType, installationPath, rulesFile string) (*SystemdService, error) {
+	// checks for systemd service type
 	if !serviceTypeAllowed(serviceType) {
-		return nil, fmt.Errorf("service type provided not allowed")
+		return nil, fmt.Errorf("service type is not allowed: %s", serviceType)
 	}
+	// checks for installation path
 	if !filepath.IsAbs(installationPath) {
-		// TODO: substitute with fmt.Errorf()
-		return nil, fmt.Errorf("installation path is not absolute")
+		return nil, fmt.Errorf("installation path is not absolute: %s", installationPath)
 	}
+	if _, err := os.Stat(installationPath); errors.Is(err, os.ErrNotExist) {
+		return nil, fmt.Errorf("installation path does not exist: %s", installationPath)
+	}
+	// checks for rules file
 	if !filepath.IsAbs(rulesFile) {
-		return nil, fmt.Errorf("rules file is not absolute")
+		return nil, fmt.Errorf("rules file path is not absolute: %s", rulesFile)
+	}
+	if _, err := os.Stat(installationPath); errors.Is(err, os.ErrNotExist) {
+		return nil, fmt.Errorf("rules file path does not exist: %s", rulesFile)
 	}
 
 	return &SystemdService{

pkg/template/template.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 	"text/template"
 )
 
@@ -14,27 +15,30 @@ type Generator interface {
 	GetFileName() string
 }
 
-func GenerateTemplate(g Generator, destinationPath string) error {
+func GenerateTemplate(g Generator, outputPath string) error {
 	tpl, err := template.New(g.GetTemplateName()).Parse(g.GetFileContent())
 	if err != nil {
-		return err
+		return fmt.Errorf("error getting template instance: %v", err)
 	}
 
-	if destinationPath == "" {
-		return nil
+	if !filepath.IsAbs(outputPath) {
+		return fmt.Errorf("output path is not absolute: %s", outputPath)
 	}
-	if !filepath.IsAbs(destinationPath){
-		return fmt.Errorf("destinationPath path is not absolute")
+	// if last char of outputPath is "/" we want to remove,
+	// so the final output will be cleaned.
+	// this way: /root/template.file instead of /root//template.file
+	if outputPath != "/" && outputPath[len(outputPath)-1:] == "/" {
+		outputPath = strings.TrimSuffix(outputPath, "/")
 	}
 
-	outFile, err := os.Create(destinationPath + "/" + g.GetFileName())
+	outFile, err := os.Create(filepath.Join(outputPath, g.GetFileName()))
 	if err != nil {
-		return err
+		return fmt.Errorf("error creating output file: %v", err)
 	}
 
 	err = tpl.Execute(outFile, g.GetTemplateStruct())
 	if err != nil {
-		return err
+		return fmt.Errorf("error writing content into file: %v", err)
 	}
 	return nil
 }