Add ALT Linux downloader

Signed-off-by: Mikhail Gordeev <obirvalger@altlinux.org>

shared/definition.go

@@ -231,6 +231,7 @@ func (d *Definition) Validate() error {
 
 	validDownloaders := []string{
 		"alpinelinux-http",
+		"alt-http",
 		"archlinux-http",
 		"centos-http",
 		"debootstrap",

sources/alt-http.go

@@ -0,0 +1,81 @@
+package sources
+
+import (
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"net/url"
+	"path/filepath"
+	"strings"
+
+	"github.com/lxc/distrobuilder/shared"
+	lxd "github.com/lxc/lxd/shared"
+)
+
+// ALTHTTP represents the ALT Linux downloader.
+type ALTHTTP struct{}
+
+// NewALTHTTP creates a new ALTHTTP instance.
+func NewALTHTTP() *ALTHTTP {
+	return &ALTHTTP{}
+}
+
+// Run downloads the tarball and unpacks it.
+func (s *ALTHTTP) Run(definition shared.Definition, rootfsDir string) error {
+	release := definition.Image.Release
+
+	baseURL := fmt.Sprintf("%s/pub/distributions/ALTLinux/images/%s/cloud/",
+		definition.Source.URL, release)
+
+	fname := fmt.Sprintf("alt-%s-rootfs-systemd-%s.tar.xz", strings.ToLower(release),
+		definition.Image.ArchitectureMapped)
+
+	url, err := url.Parse(baseURL)
+	if err != nil {
+		return err
+	}
+
+	checksumFile := ""
+	if !definition.Source.SkipVerification {
+		if len(definition.Source.Keys) != 0 {
+
+			checksumFile = baseURL + "SHA256SUM"
+			fpath, err := shared.DownloadHash(definition.Image, checksumFile+".asc", "", nil)
+			if err != nil {
+				return err
+			}
+
+			shared.DownloadHash(definition.Image, checksumFile, "", nil)
+
+			valid, err := shared.VerifyFile(
+				filepath.Join(fpath, "SHA256SUM"),
+				filepath.Join(fpath, "SHA256SUM.asc"),
+				definition.Source.Keys,
+				definition.Source.Keyserver)
+			if err != nil {
+				return err
+			}
+			if !valid {
+				return fmt.Errorf("Failed to validate tarball")
+			}
+		} else {
+			// Force gpg checks when using http
+			if url.Scheme != "https" {
+				return errors.New("GPG keys are required if downloading from HTTP")
+			}
+		}
+	}
+
+	fpath, err := shared.DownloadHash(definition.Image, baseURL+fname, checksumFile, sha256.New())
+	if err != nil {
+		return err
+	}
+
+	// Unpack
+	err = lxd.Unpack(filepath.Join(fpath, fname), rootfsDir, false, false, nil)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

sources/source.go

@@ -12,6 +12,8 @@ func Get(name string) Downloader {
 	switch name {
 	case "alpinelinux-http":
 		return NewAlpineLinuxHTTP()
+	case "alt-http":
+		return NewALTHTTP()
 	case "archlinux-http":
 		return NewArchLinuxHTTP()
 	case "centos-http":