utils.go

package pkg

import (
	"archive/tar"
	"compress/gzip"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"strings"

	"gopkg.in/yaml.v2"
)

// ParseConfig takes a response body from the controller and returns a Config object.
func ParseConfig(body []byte) (*Config, error) {
	var config Config
	err := json.Unmarshal(body, &config)
	return &config, err
}

// GetDefaultType returns the default process types given a YAML byte array.
func GetDefaultType(bytes []byte) (string, error) {
	type YamlTypeMap struct {
		DefaultProcessTypes ProcessType `yaml:"default_process_types"`
	}

	var p YamlTypeMap

	if err := yaml.Unmarshal(bytes, &p); err != nil {
		return "", err
	}

	retVal, err := json.Marshal(&p.DefaultProcessTypes)

	if err != nil {
		return "", err
	}

	if len(p.DefaultProcessTypes) == 0 {
		return "{}", nil
	}

	return string(retVal), nil
}

// ParseControllerConfig returns configuration key/value pair strings from a config.
func ParseControllerConfig(bytes []byte) ([]string, error) {
	var controllerConfig Config
	if err := json.Unmarshal(bytes, &controllerConfig); err != nil {
		return []string{}, err
	}

	if controllerConfig.Values == nil {
		return []string{""}, nil
	}

	retVal := []string{}
	for k, v := range controllerConfig.Values {
		retVal = append(retVal, fmt.Sprintf(" -e %s=\"%v\"", k, v))
	}
	return retVal, nil
}

// Extract opens sourcefile and, if it has a '.gz' extension, unzips it using a gzip.Reader.
// then, it untars it using a tar.Reader
func Extract(sourcefile string) (err error) {

	file, err := os.Open(sourcefile)

	if err != nil {
		fmt.Println(err)
		return err
	}

	defer file.Close()

	var fileReader io.ReadCloser = file

	// just in case we are reading a tar.gz file, add a filter to handle gzipped file
	if strings.HasSuffix(sourcefile, ".gz") {
		if fileReader, err = gzip.NewReader(file); err != nil {

			fmt.Println(err)
			return err
		}
		defer fileReader.Close()
	}

	tarBallReader := tar.NewReader(fileReader)

	// Extracting tarred files

	for {
		header, err := tarBallReader.Next()
		if err != nil {
			if err == io.EOF {
				break
			}
			fmt.Println(err)
			return err
		}

		// get the individual filename and extract to the current directory
		filename := header.Name

		switch header.Typeflag {
		case tar.TypeDir:
			// handle directory
			fmt.Println("Creating directory :", filename)
			err = os.MkdirAll(filename, os.FileMode(header.Mode)) // or use 0755 if you prefer

			if err != nil {
				fmt.Println(err)
				os.Exit(1)
			}

		case tar.TypeReg:
			// handle normal file
			fmt.Println("Untarring :", filename)
			writer, err := os.Create(filename)

			if err != nil {
				fmt.Println(err)
				return err
			}

			io.Copy(writer, tarBallReader)

			err = os.Chmod(filename, os.FileMode(header.Mode))

			if err != nil {
				fmt.Println(err)
				return err
			}

			writer.Close()
		default:
			fmt.Printf("Unable to untar type : %c in file %s", header.Typeflag, filename)
		}
	}
	return nil
}