Merge pull request kubernetes-sigs#7828 from Rohitrajak1807/private/Rohitrajak1807/output-flag

✨ Add output flag, change printYaml function signature

Author: k8s-ci-robot

cmd/clusterctl/cmd/generate_cluster.go

@@ -42,6 +42,8 @@ type generateClusterOptions struct {
 	configMapDataKey   string
 
 	listVariables bool
+
+	output string
 }
 
 var gc = &generateClusterOptions{}
@@ -137,6 +139,7 @@ func init() {
 	// other flags
 	generateClusterClusterCmd.Flags().BoolVar(&gc.listVariables, "list-variables", false,
 		"Returns the list of variables expected by the template instead of the template yaml")
+	generateClusterClusterCmd.Flags().StringVar(&gc.output, "write-to", "", "Specify the output file to write the template to, defaults to STDOUT if the flag is not set")
 
 	generateCmd.AddCommand(generateClusterClusterCmd)
 }
@@ -192,5 +195,5 @@ func runGenerateClusterTemplate(cmd *cobra.Command, name string) error {
 		return printVariablesOutput(template, templateOptions)
 	}
 
-	return printYamlOutput(template)
+	return printYamlOutput(template, gc.output)
 }

cmd/clusterctl/cmd/generate_provider.go

@@ -34,6 +34,7 @@ type generateProvidersOptions struct {
 	targetNamespace          string
 	textOutput               bool
 	raw                      bool
+	outputFile               string
 }
 
 var gpo = &generateProvidersOptions{}
@@ -95,6 +96,8 @@ func init() {
 	generateProviderCmd.Flags().BoolVar(&gpo.raw, "raw", false,
 		"Generate configuration without variable substitution in a yaml format.")
 
+	generateProviderCmd.Flags().StringVar(&gpo.outputFile, "write-to", "", "Specify the output file to write the template to, defaults to STDOUT if the flag is not set")
+
 	generateCmd.AddCommand(generateProviderCmd)
 }
 
@@ -122,7 +125,7 @@ func runGenerateProviderComponents() error {
 		return printComponentsAsText(components)
 	}
 
-	return printYamlOutput(components)
+	return printYamlOutput(components, gpo.outputFile)
 }
 
 // parseProvider parses command line flags and returns the provider name and type.

cmd/clusterctl/cmd/util.go

@@ -32,16 +32,23 @@ import (
 	"sigs.k8s.io/cluster-api/cmd/clusterctl/client"
 )
 
-// printYamlOutput prints the yaml content of a generated template to stdout.
-func printYamlOutput(printer client.YamlPrinter) error {
+// printYamlOutput prints the yaml content of a generated template to stdout or to a local file if specified.
+func printYamlOutput(printer client.YamlPrinter, outputFile string) error {
 	yaml, err := printer.Yaml()
 	if err != nil {
 		return err
 	}
+	outputFile = filepath.Clean(strings.TrimSpace(outputFile))
 	yaml = append(yaml, '\n')
+	if outputFile == "" || outputFile == "-" {
+		if _, err := os.Stdout.Write(yaml); err != nil {
+			return errors.Wrap(err, "failed to write yaml to Stdout")
+		}
+		return nil
+	}
 
-	if _, err := os.Stdout.Write(yaml); err != nil {
-		return errors.Wrap(err, "failed to write yaml to Stdout")
+	if err := os.WriteFile(outputFile, yaml, 0600); err != nil {
+		return errors.Wrap(err, "failed to write to destination file")
 	}
 	return nil
 }