func.startup.go

package main

import (
	"flag"
	"os"

	"gopkg.in/yaml.v2"
)

// PreflightSetup just makes sure the stage is set before starting the application
func PreflightSetup() {
	logStdOut("Preflight complete!")
}

// FilePreflightSetup just makes sure the stage is set before starting file mode operations
func FilePreflightSetup() {
	logStdOut("File Mode Preflight complete!")
}

// ServerPreflightSetup just makes sure the stage is set before starting the HTTP server
func ServerPreflightSetup() {
	logStdOut("Server Mode Preflight complete!")
}

// NewConfig returns a new decoded Config struct
func NewConfig(configPath CLIOpts) (*Config, error) {
	// Create config structure
	config := &Config{}

	// Open config file
	file, err := os.Open(configPath.Config)
	checkAndFail(err)
	defer file.Close()

	// Init new YAML decode
	d := yaml.NewDecoder(file)

	// Start YAML decoding from file
	if err := d.Decode(&config); err != nil {
		return nil, err
	}

	//readConfig = config

	return config, nil
}

// NewDNSServer returns a new decoded DNS Server configuration struct
func NewDNSServer(configPath CLIOpts) (*RootYAML, error) {
	// Create config structure
	config := &RootYAML{}

	// Open config file
	file, err := os.Open(configPath.Source)
	checkAndFail(err)
	defer file.Close()

	// Init new YAML decode
	d := yaml.NewDecoder(file)

	// Start YAML decoding from file
	if err := d.Decode(&config); err != nil {
		return nil, err
	}

	return config, nil
}

// ParseFlags will create and parse the CLI flags
// and return the path to be used elsewhere
func ParseFlags() (CLIOpts, error) {
	// String that contains the configured configuration path
	var configPath string
	// String that contains the mode
	var mode string
	// String that contains the input yaml
	var source string
	// String that contains the destination directory
	var dir string

	// Set up a CLI flag called "-mode" to allow users
	// to switch between file input/output and server mode
	flag.StringVar(&mode, "mode", "", "Mode: File | Server, eg '-mode=server'")

	// Set up a CLI flag called "-source" to allow users
	// to specify a YAML Zone defintion input file
	flag.StringVar(&source, "source", "", "Source YAML Zones Definition, eg '-source=./zones.yml'")

	// Set up a CLI flag called "-dir" to allow users
	// to specify the target directory for generated zone and configuration files
	flag.StringVar(&dir, "dir", "", "Target directory for generated files, eg '-dir=./generated'")

	// Set up a CLI flag called "-config" to allow users
	// to supply the configuration file
	flag.StringVar(&configPath, "config", "", "path to config file, eg '-config=./config.yml'")

	// Actually parse the flags
	flag.Parse()

	switch mode {
	case "server":
		if configPath == "" {
			return CLIOpts{}, Stoerr("[Server Mode]: No server configuration defined! (-config=./config.yml)")
		}
		// Validate the path first
		if err := ValidateConfigPath(configPath); err != nil {
			return CLIOpts{}, err
		}

	case "file":
		if source == "" {
			return CLIOpts{}, Stoerr("[File Mode]: No source YAML defined! (-source=./zones.yml)")
		}
		// Validate the source file first
		if err := ValidateConfigPath(source); err != nil {
			return CLIOpts{}, err
		}

		if dir == "" {
			return CLIOpts{}, Stoerr("[File Mode]: No target directory defined! (-dir=./generated)")
		}
		// Validate the dir directory first
		if err := ValidateConfigDirectory(dir); err != nil {
			return CLIOpts{}, err
		}

	default:
		if source == "" {
			return CLIOpts{}, Stoerr("[File Mode]: No source YAML defined! (-source=./zones.yml)")
		}
		// Validate the source file first
		if err := ValidateConfigPath(source); err != nil {
			return CLIOpts{}, err
		}

		if dir == "" {
			return CLIOpts{}, Stoerr("[File Mode]: No target directory defined! (-dir=./generated)")
		}
		// Validate the dir directory first
		if err := ValidateConfigDirectory(dir); err != nil {
			return CLIOpts{}, err
		}

	}

	SetCLIOpts := CLIOpts{
		Config: configPath,
		Mode:   mode,
		Dir:    dir,
		Source: source}

	// Return the configuration path
	return SetCLIOpts, nil
}