func()

in lib/ec2macosinit/motd.go [21:68]
31 lines of code
7 McCabe index (conditional complexity)

func (c *MOTDModule) Do(ctx *ModuleContext) (message string, err error) {
	if !c.UpdateName {
		return "Not requested to update MOTD", nil
	}

	// Create the macOS string
	macosStr := "macOS"

	// Create regex pattern to be replaced in the motd file
	motdMacOSExpression, err := regexp.Compile("macOS.*")
	if err != nil {
		return "", fmt.Errorf("ec2macosinit: error compiling motd regex pattern: %s", err)
	}

	// Get the os product version number
	osProductVersion, err := getOSProductVersion()
	if err != nil {
		return "", fmt.Errorf("ec2macosinit: error while getting product version: %s", err)
	}

	// Get the version name using the os product version number
	versionName := getVersionName(osProductVersion)

	// Create the version string to be written to the motd file
	var motdString string
	if versionName != "" {
		motdString = fmt.Sprintf("%s %s %s", macosStr, versionName, osProductVersion)
	} else {
		motdString = fmt.Sprintf("%s %s", macosStr, osProductVersion)
	}

	// Read in the raw contents of the motd file
	rawFileContents, err := os.ReadFile(motdFile)
	if err != nil {
		return "", fmt.Errorf("ec2macosinit: error reading motd file: %s", err)
	}

	// Use the regexp object to replace all instances of the pattern with the updated motd version string
	replacedContents := motdMacOSExpression.ReplaceAll(rawFileContents, []byte(motdString))

	// Write the updated contents back to the motd file
	err = os.WriteFile(motdFile, replacedContents, 0644)
	if err != nil {
		return "", fmt.Errorf("ec2macosinit: error writing updated motd back to file: %s", err)
	}

	return fmt.Sprintf("successfully updated motd file [%s] with version string [%s]", motdFile, motdString), nil
}