Better error handling and Handle potential permissions issue

err could be nil, so it is checked before checking for the
type of error. This may not be needed, but is a better
default to establish since code is often copied by new
contributors when adding features.

Addresses comment by @rgee0 for handling error from stat.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

builder/build.go

@@ -34,7 +34,7 @@ func BuildImage(image string, handler string, functionName string, language stri
 
 	if stack.IsValidTemplate(language) {
 		pathToTemplateYAML := fmt.Sprintf("./template/%s/template.yml", language)
-		if _, err := os.Stat(pathToTemplateYAML); os.IsNotExist(err) {
+		if _, err := os.Stat(pathToTemplateYAML); err != nil && os.IsNotExist(err) {
 			return err
 		}
 

builder/copy_test.go

@@ -103,7 +103,7 @@ func checkDestinationFiles(dir string, numberOfFiles, mode int) error {
 	// Check each file inside the destination folder
 	for i := 1; i <= numberOfFiles; i++ {
 		fileStat, err := os.Stat(fmt.Sprintf("%s/test-file-%d", dir, i))
-		if os.IsNotExist(err) {
+		if err != nil && os.IsNotExist(err) {
 			return err
 		}
 		if fileStat.Mode() != os.FileMode(mode) {

builder/publish.go

@@ -48,7 +48,7 @@ func PublishImage(image string, handler string, functionName string, language st
 
 	if stack.IsValidTemplate(language) {
 		pathToTemplateYAML := fmt.Sprintf("./template/%s/template.yml", language)
-		if _, err := os.Stat(pathToTemplateYAML); os.IsNotExist(err) {
+		if _, err := os.Stat(pathToTemplateYAML); err != nil && os.IsNotExist(err) {
 			return err
 		}
 

commands/build.go

@@ -179,8 +179,8 @@ func runBuild(cmd *cobra.Command, args []string) error {
 		}
 	} else {
 		templateAddress := getTemplateURL("", os.Getenv(templateURLEnvironment), DefaultTemplateRepository)
-		if pullErr := pullTemplates(templateAddress, templateName); pullErr != nil {
-			return fmt.Errorf("could not pull templates for OpenFaaS: %v", pullErr)
+		if err := pullTemplates(templateAddress, templateName); err != nil {
+			return fmt.Errorf("could not pull templates: %v", err)
 		}
 	}
 
@@ -307,12 +307,18 @@ func build(services *stack.Services, queueDepth int, shrinkwrap, quietBuild bool
 // pullTemplates pulls templates from specified git remote. templateURL may be a pinned repository.
 func pullTemplates(templateURL, templateName string) error {
 
-	if _, err := os.Stat("./template"); err != nil && os.IsNotExist(err) {
+	if _, err := os.Stat("./template"); err != nil {
+		if os.IsNotExist(err) {
 
-		fmt.Printf("No templates found in current directory.\n")
+			fmt.Printf("No templates found in current directory.\n")
 
-		templateURL, refName := versioncontrol.ParsePinnedRemote(templateURL)
-		if err := fetchTemplates(templateURL, refName, templateName, false); err != nil {
+			templateURL, refName := versioncontrol.ParsePinnedRemote(templateURL)
+			if err := fetchTemplates(templateURL, refName, templateName, false); err != nil {
+				return err
+			}
+		} else {
+
+			// Perhaps there was a permissions issue or something else.
 			return err
 		}
 	}

commands/deploy.go

@@ -458,7 +458,7 @@ func deriveFprocess(function stack.Function) (string, error) {
 	}
 
 	pathToTemplateYAML := "./template/" + function.Language + "/template.yml"
-	if _, err := os.Stat(pathToTemplateYAML); os.IsNotExist(err) {
+	if _, err := os.Stat(pathToTemplateYAML); err != nil && os.IsNotExist(err) {
 		return "", err
 	}
 

commands/new_function.go

@@ -207,7 +207,7 @@ Download templates:
 	}
 
 	pathToTemplateYAML := fmt.Sprintf("./template/%s/template.yml", language)
-	if _, err := os.Stat(pathToTemplateYAML); os.IsNotExist(err) {
+	if _, err := os.Stat(pathToTemplateYAML); err != nil && os.IsNotExist(err) {
 		return err
 	}
 

commands/new_function_test.go

@@ -150,18 +150,18 @@ func runNewFunctionTest(t *testing.T, nft NewFunctionTest) {
 	if nft.expectedMsg == SuccessMsg {
 
 		// Make sure that the folder and file was created:
-		if _, err := os.Stat("./" + dirName); os.IsNotExist(err) {
+		if _, err := os.Stat("./" + dirName); err != nil && os.IsNotExist(err) {
 			t.Fatalf("%s/ directory was not created", dirName)
 		}
 
 		// Check that the Dockerfile was created
 		if funcLang == "Dockerfile" || funcLang == "dockerfile" {
-			if _, err := os.Stat("./" + dirName + "/Dockerfile"); os.IsNotExist(err) {
+			if _, err := os.Stat("./" + dirName + "/Dockerfile"); err != nil && os.IsNotExist(err) {
 				t.Fatalf("Dockerfile language should create a Dockerfile for you: %s", funcName)
 			}
 		}
 
-		if _, err := os.Stat(funcYAML); os.IsNotExist(err) {
+		if _, err := os.Stat(funcYAML); err != nil && os.IsNotExist(err) {
 			t.Fatalf("\"%s\" yaml file was not created", funcYAML)
 		}
 

commands/plugin_get.go

@@ -99,7 +99,7 @@ func runPluginGetCmd(cmd *cobra.Command, args []string) error {
 		}
 	}
 
-	if _, err := os.Stat(pluginDir); os.IsNotExist(err) {
+	if _, err := os.Stat(pluginDir); err != nil && os.IsNotExist(err) {
 		if err := os.MkdirAll(pluginDir, 0755); err != nil && os.ErrExist != err {
 			return fmt.Errorf("failed to create plugin directory %s: %w", pluginDir, err)
 		}

commands/publish.go

@@ -164,7 +164,7 @@ func runPublish(cmd *cobra.Command, args []string) error {
 	}
 
 	if needTemplates {
-		if _, err := os.Stat("./template"); os.IsNotExist(err) {
+		if _, err := os.Stat("./template"); err != nil && os.IsNotExist(err) {
 
 			return fmt.Errorf(`the "template" directory is missing but required by at least one function`)
 		}

commands/registry_login.go

@@ -174,7 +174,7 @@ func generateECRRegistryAuth(accountID, region string) ([]byte, error) {
 
 func writeFileToFassCLITmp(fileBytes []byte) error {
 	path := "./credentials"
-	if _, err := os.Stat(path); os.IsNotExist(err) {
+	if _, err := os.Stat(path); err != nil && os.IsNotExist(err) {
 		err := os.Mkdir(path, 0744)
 		if err != nil {
 			return err

commands/template_pull_stack.go

@@ -93,7 +93,7 @@ func filterExistingTemplates(templateInfo []stack.TemplateSource, templatesDir s
 	var newTemplates []stack.TemplateSource
 	for _, info := range templateInfo {
 		templatePath := fmt.Sprintf("%s/%s", templatesDir, info.Name)
-		if _, err := os.Stat(templatePath); os.IsNotExist(err) {
+		if _, err := os.Stat(templatePath); err != nil && os.IsNotExist(err) {
 			newTemplates = append(newTemplates, info)
 		}
 	}

config/config_file.go

@@ -135,7 +135,7 @@ func EnsureFile() (string, error) {
 		return "", err
 	}
 
-	if _, err := os.Stat(filePath); os.IsNotExist(err) {
+	if _, err := os.Stat(filePath); err != nil && os.IsNotExist(err) {
 		file, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
 		if err != nil {
 			return "", err
@@ -155,7 +155,7 @@ func fileExists() bool {
 	}
 
 	filePath := path.Clean(filepath.Join(dirPath, DefaultFile))
-	if _, err := os.Stat(filePath); os.IsNotExist(err) {
+	if _, err := os.Stat(filePath); err != nil && os.IsNotExist(err) {
 		return false
 	}
 
@@ -185,7 +185,7 @@ func (configFile *ConfigFile) save() error {
 func (configFile *ConfigFile) load() error {
 	conf := &ConfigFile{}
 
-	if _, err := os.Stat(configFile.FilePath); os.IsNotExist(err) {
+	if _, err := os.Stat(configFile.FilePath); err != nil && os.IsNotExist(err) {
 		return fmt.Errorf("can't load config from non existent filePath")
 	}
 

config/config_file_test.go

@@ -234,8 +234,7 @@ func Test_EnsureFile(t *testing.T) {
 	if err != nil {
 		t.Error(err.Error())
 	}
-	_, err = os.Stat(cfg)
-	if os.IsNotExist(err) {
+	if _, err = os.Stat(cfg); err != nil && os.IsNotExist(err) {
 		t.Errorf("expected config at %s", cfg)
 	}
 }