main.go

package main

import (
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"strings"

	utils "github.com/maorfr/helm-plugin-utils/pkg"
	helm_restore "github.com/maorfr/helm-restore/pkg"

	"github.com/mholt/archiver"
	"github.com/spf13/cobra"
)

var (
	releaseName     string
	tillerNamespace string
	label           string
	file            string
	restore         bool
)

func main() {
	cmd := &cobra.Command{
		Use:   "backup [flags] NAMESPACE",
		Short: "backup/restore releases in a namespace to/from a file",
		Args: func(cmd *cobra.Command, args []string) error {
			if len(args) != 1 {
				return errors.New("namespace to backup has to be defined")
			}
			return nil
		},

		RunE: run,
	}

	f := cmd.Flags()
	f.StringVarP(&tillerNamespace, "tiller-ns","t", "kube-system", "namespace of Tiller")
	f.StringVarP(&label, "label", "l", "OWNER=TILLER", "label to select tiller resources by")
	f.StringVar(&file, "file", "", "file name to use (.tgz file). If not provided - will use <namespace>.tgz")
	f.BoolVarP(&restore, "restore", "r", false, "restore instead of backup")

	if err := cmd.Execute(); err != nil {
		os.Exit(1)
	}
}

func run(cmd *cobra.Command, args []string) error {
	namespace := args[0]
	if restore {
		if err := Restore(namespace); err != nil {
			return err
		}
	} else {
		if err := Backup(namespace); err != nil {
			return err
		}
	}

	return nil
}

// Backup performs a backup of all releases from provided namespace
func Backup(namespace string) error {
	log.Println("getting tiller storage")
	storage := utils.GetTillerStorage(tillerNamespace)
	log.Printf("found tiller storage: %s", storage)
	log.Printf("getting releases in namespace \"%s\"", namespace)
	inReleases, err := utils.ListReleaseNamesInNamespace(utils.ListReleaseNamesInNamespaceOptions{
		Namespace:       namespace,
		TillerNamespace: tillerNamespace,
	})
	if err != nil {
		return err
	}
	if len(inReleases) == 0 {
		return fmt.Errorf("no releases found in namespace \"%s\"", namespace)
	}
	log.Printf("found relases: %s", prettyPrint(inReleases))
	backupCmd := []string{
		"kubectl",
		"--namespace", tillerNamespace,
		"get", storage,
		"-l", label,
		"-l", "NAME in (" + inReleases + ")",
		"-o", "yaml",
	}
	log.Println("getting backup data")
	output := utils.Execute(backupCmd)
	log.Println("successfully got backup data")

	manifestsFileName := "manifests.yaml"
	releasesFileName := "releases"
	tarGzName := getTarGzFileName(namespace)
	os.Remove(manifestsFileName)
	os.Remove(releasesFileName)
	os.Remove(tarGzName)
	log.Printf("writing backup to file %s", tarGzName)
	if err := ioutil.WriteFile(manifestsFileName, output, 0644); err != nil {
		return err
	}
	if err := ioutil.WriteFile(releasesFileName, []byte(inReleases), 0644); err != nil {
		return err
	}
	err = archiver.TarGz.Make(tarGzName, []string{manifestsFileName, releasesFileName})
	if err != nil {
		return err
	}
	os.Remove(manifestsFileName)
	os.Remove(releasesFileName)
	log.Printf("backup of namespace \"%s\" to file %s complete\n", namespace, tarGzName)
	return nil
}

// Restore performs a restore of all releases to provided namespace
func Restore(namespace string) error {
	untarDir := "restore"
	manifestsFileName := untarDir + "/manifests.yaml"
	releasesFileName := untarDir + "/releases"
	os.RemoveAll(untarDir)
	tarGzName := getTarGzFileName(namespace)
	log.Printf("extracting backup from file %s", tarGzName)
	if err := archiver.TarGz.Open(tarGzName, untarDir); err != nil {
		return err
	}
	log.Println("reading backup data")
	releases, err := ioutil.ReadFile(releasesFileName)
	if err != nil {
		return err
	}
	restoreCmd := []string{
		"kubectl",
		"--namespace", tillerNamespace,
		"create", "-f", manifestsFileName,
	}
	releasesToRestore := (string)(releases)
	log.Printf("releases found to restore: %s", prettyPrint(releasesToRestore))
	log.Println("applying backup data to tiller (this command will fail if releases exist)")
	output := utils.ExecuteCombined(restoreCmd)
	log.Print((string)(output))

	label += ",STATUS=DEPLOYED"
	for _, r := range strings.Split((string)(releasesToRestore), ",") {
		log.Printf("restoring release \"%s\"", r)
		helm_restore.Restore(r, tillerNamespace, label)
	}

	os.RemoveAll(untarDir)
	log.Printf("restore file %s to namespace \"%s\" complete", tarGzName, namespace)
	return nil
}

func getTarGzFileName(namespace string) string {
	tarGzName := file
	if tarGzName == "" {
		tarGzName = namespace
	}
	if !strings.HasSuffix(tarGzName, ".tgz") {
		tarGzName = tarGzName + ".tgz"
	}

	return tarGzName
}

func prettyPrint(in string) string {
	return strings.Replace(in, ",", ", ", -1)
}