feat: support template bundles as zip archives (#11839)

coderd/fileszip.go

@@ -0,0 +1,101 @@
+package coderd
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"bytes"
+	"errors"
+	"io"
+	"log"
+)
+
+func CreateTarFromZip(zipReader *zip.Reader) ([]byte, error) {
+	var tarBuffer bytes.Buffer
+	err := writeTarArchive(&tarBuffer, zipReader)
+	if err != nil {
+		return nil, err
+	}
+	return tarBuffer.Bytes(), nil
+}
+
+func writeTarArchive(w io.Writer, zipReader *zip.Reader) error {
+	tarWriter := tar.NewWriter(w)
+	defer tarWriter.Close()
+
+	for _, file := range zipReader.File {
+		err := processFileInZipArchive(file, tarWriter)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func processFileInZipArchive(file *zip.File, tarWriter *tar.Writer) error {
+	fileReader, err := file.Open()
+	if err != nil {
+		return err
+	}
+	defer fileReader.Close()
+
+	err = tarWriter.WriteHeader(&tar.Header{
+		Name: file.Name,
+		Size: file.FileInfo().Size(),
+		Mode: 0o644,
+	})
+	if err != nil {
+		return err
+	}
+
+	n, err := io.CopyN(tarWriter, fileReader, httpFileMaxBytes)
+	log.Println(file.Name, n, err)
+	if errors.Is(err, io.EOF) {
+		err = nil
+	}
+	return err
+}
+
+func CreateZipFromTar(tarReader *tar.Reader) ([]byte, error) {
+	var zipBuffer bytes.Buffer
+	err := WriteZipArchive(&zipBuffer, tarReader)
+	if err != nil {
+		return nil, err
+	}
+	return zipBuffer.Bytes(), nil
+}
+
+func WriteZipArchive(w io.Writer, tarReader *tar.Reader) error {
+	zipWriter := zip.NewWriter(w)
+	defer zipWriter.Close()
+
+	for {
+		tarHeader, err := tarReader.Next()
+		if errors.Is(err, io.EOF) {
+			break
+		}
+
+		if err != nil {
+			return err
+		}
+
+		zipHeader, err := zip.FileInfoHeader(tarHeader.FileInfo())
+		if err != nil {
+			return err
+		}
+		zipHeader.Name = tarHeader.Name
+
+		zipEntry, err := zipWriter.CreateHeader(zipHeader)
+		if err != nil {
+			return err
+		}
+
+		_, err = io.CopyN(zipEntry, tarReader, httpFileMaxBytes)
+		if errors.Is(err, io.EOF) {
+			err = nil
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil // don't need to flush as we call `writer.Close()`
+}