Add support for unpacking archives after download

updater/packers.go

@@ -1,13 +0,0 @@
-package updater
-
-import (
-	"compress/gzip"
-	"io"
-)
-
-// UnpackGZIP unpacks a GZIP compressed reader r
-// and returns a new reader. It's suitable to be
-// used with registry.GetPackedFile.
-func UnpackGZIP(r io.Reader) (io.Reader, error) {
-	return gzip.NewReader(r)
-}

updater/registry.go

@@ -26,6 +26,7 @@ type ResourceRegistry struct {
 	UpdateURLs       []string
 	UserAgent        string
 	MandatoryUpdates []string
+	AutoUnpack       []string
 
 	Beta    bool
 	DevMode bool

updater/unpacking.go

@@ -0,0 +1,176 @@
+package updater
+
+import (
+	"archive/zip"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"github.com/safing/portbase/log"
+
+	"github.com/hashicorp/go-multierror"
+	"github.com/safing/portbase/utils"
+)
+
+// UnpackGZIP unpacks a GZIP compressed reader r
+// and returns a new reader. It's suitable to be
+// used with registry.GetPackedFile.
+func UnpackGZIP(r io.Reader) (io.Reader, error) {
+	return gzip.NewReader(r)
+}
+
+// UnpackResources unpacks all resources defined in the AutoUnpack list.
+func (reg *ResourceRegistry) UnpackResources() error {
+	reg.RLock()
+	defer reg.RUnlock()
+
+	var multierr *multierror.Error
+	for _, res := range reg.resources {
+		if utils.StringInSlice(reg.AutoUnpack, res.Identifier) {
+			err := res.UnpackArchive()
+			if err != nil {
+				multierr = multierror.Append(multierr, err)
+			}
+		}
+	}
+
+	return multierr.ErrorOrNil()
+}
+
+const (
+	zipSuffix = ".zip"
+)
+
+// UnpackArchive unpacks the archive the resource refers to. The contents are
+// unpacked into a directory with the same name as the file, excluding the
+// suffix. If the destination folder already exists, it is assumed that the
+// contents have already been correctly unpacked.
+func (res *Resource) UnpackArchive() error {
+	res.Lock()
+	defer res.Unlock()
+
+	// Only unpack selected versions.
+	if res.SelectedVersion == nil {
+		return nil
+	}
+
+	switch {
+	case strings.HasSuffix(res.Identifier, zipSuffix):
+		return res.unpackZipArchive()
+	default:
+		return fmt.Errorf("unsupported file type for unpacking")
+	}
+}
+
+func (res *Resource) unpackZipArchive() (err error) {
+	// Get file and directory paths.
+	archiveFile := res.SelectedVersion.storagePath()
+	destDir := strings.TrimSuffix(archiveFile, zipSuffix)
+	tmpDir := filepath.Join(
+		res.registry.tmpDir.Path,
+		filepath.FromSlash(strings.TrimSuffix(
+			path.Base(res.SelectedVersion.versionedPath()),
+			zipSuffix,
+		)),
+	)
+
+	// Check status of destination.
+	dstStat, err := os.Stat(destDir)
+	switch {
+	case os.IsNotExist(err):
+		// The destination does not exist, continue with unpacking.
+	case err != nil:
+		return fmt.Errorf("cannot access destination for unpacking: %w", err)
+	case !dstStat.IsDir():
+		return fmt.Errorf("destination for unpacking is blocked by file: %s", dstStat.Name())
+	default:
+		// Archive already seems to be unpacked.
+		return nil
+	}
+
+	// Create the tmp directory for unpacking.
+	err = res.registry.tmpDir.EnsureAbsPath(tmpDir)
+	if err != nil {
+		return fmt.Errorf("failed to create tmp dir for unpacking: %s", err)
+	}
+
+	// Defer clean up of directories.
+	defer func() {
+		// Always clean up the tmp dir.
+		_ = os.RemoveAll(tmpDir)
+		// Cleanup the destination in case of an error.
+		if err != nil {
+			_ = os.RemoveAll(destDir)
+		}
+	}()
+
+	// Open the archive for reading.
+	var archiveReader *zip.ReadCloser
+	archiveReader, err = zip.OpenReader(archiveFile)
+	if err != nil {
+		return
+	}
+	defer archiveReader.Close()
+
+	// Save all files to the tmp dir.
+	for _, file := range archiveReader.File {
+		err = copyFromZipArchive(
+			file,
+			filepath.Join(tmpDir, filepath.FromSlash(file.Name)),
+		)
+		if err != nil {
+			return
+		}
+	}
+
+	// Make the final move.
+	err = os.Rename(tmpDir, destDir)
+	if err != nil {
+		return
+	}
+
+	// Fix permissions on the destination dir.
+	err = res.registry.storageDir.EnsureAbsPath(destDir)
+	if err != nil {
+		return
+	}
+
+	log.Infof("%s: unpacked %s", res.registry.Name, res.SelectedVersion.versionedPath())
+	return nil
+}
+
+func copyFromZipArchive(archiveFile *zip.File, dstPath string) error {
+	// If file is a directory, create it and continue.
+	if archiveFile.FileInfo().IsDir() {
+		err := os.Mkdir(dstPath, archiveFile.Mode())
+		if err != nil {
+			return err
+		}
+		return nil
+	}
+
+	// Open archived file for reading.
+	fileReader, err := archiveFile.Open()
+	if err != nil {
+		return err
+	}
+	defer fileReader.Close()
+
+	// Open destination file for writing.
+	dstFile, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, archiveFile.Mode())
+	if err != nil {
+		return err
+	}
+	defer dstFile.Close()
+
+	// Copy full file from archive to dst.
+	if _, err := io.Copy(dstFile, fileReader); err != nil {
+		return err
+	}
+
+	return nil
+}