Pass content-length from gitlab-zip-cat

cmd/gitlab-zip-cat/main.go

@@ -30,14 +30,14 @@ func main() {
 	archive, err := zip.OpenReader(archiveFileName)
 	if err != nil {
 		printError(fmt.Errorf("open %q: %v", archiveFileName, err))
-		os.Exit(notFound)
+		exitNotFound()
 	}
 	defer archive.Close()
 
 	file := findFileInZip(fileName, &archive.Reader)
 	if file == nil {
 		printError(fmt.Errorf("find %q in %q: not found", fileName, archiveFileName))
-		os.Exit(notFound)
+		exitNotFound()
 	}
 	// Start decompressing the file
 	reader, err := file.Open()
@@ -45,10 +45,14 @@ func main() {
 		fatalError(fmt.Errorf("open %q in %q: %v", fileName, archiveFileName, err))
 	}
 	defer reader.Close()
+
+	if _, err := fmt.Printf("%d\n", file.UncompressedSize64); err != nil {
+		fatalError(fmt.Errorf("write file size: %v", err))
+	}
+
 	if _, err := io.Copy(os.Stdout, reader); err != nil {
 		fatalError(fmt.Errorf("write %q from %q to stdout: %v", fileName, archiveFileName, err))
 	}
-
 }
 
 func findFileInZip(fileName string, archive *zip.Reader) *zip.File {
@@ -68,3 +72,8 @@ func fatalError(err error) {
 	printError(err)
 	os.Exit(1)
 }
+
+func exitNotFound() {
+	fmt.Printf("%d\n", -notFound) // for the content-length reader
+	os.Exit(notFound)
+}

internal/artifacts/artifact_download.go

@@ -3,6 +3,7 @@ package artifacts
 import (
 	"../api"
 	"../helper"
+	"bufio"
 	"encoding/base64"
 	"errors"
 	"fmt"
@@ -12,11 +13,14 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 	"syscall"
 )
 
 const exitStatusNotFound = 2
 
+var notFoundString = fmt.Sprintf("%d", -exitStatusNotFound)
+
 func decodeFileEntry(entry string) (string, error) {
 	decoded, err := base64.StdEncoding.DecodeString(entry)
 	if err != nil {
@@ -45,14 +49,24 @@ func unpackFileFromZip(archiveFileName, fileName string, headers http.Header, ou
 		return fmt.Errorf("start %v: %v", catFile.Args, err)
 	}
 	defer helper.CleanUpProcessGroup(catFile)
+
 	basename := filepath.Base(fileName)
+	reader := bufio.NewReader(stdout)
+	contentLength, err := reader.ReadString('\n')
+	if err != nil {
+		return fmt.Errorf("read content-length: %v", err)
+	}
+	contentLength = strings.TrimSuffix(contentLength, "\n")
+	if contentLength == notFoundString {
+		return os.ErrNotExist
+	}
 
 	// Write http headers about the file
+	headers.Set("Content-Length", contentLength)
 	headers.Set("Content-Type", detectFileContentType(fileName))
 	headers.Set("Content-Disposition", "attachment; filename=\""+escapeQuotes(basename)+"\"")
-
 	// Copy file body to client
-	if _, err := io.Copy(output, stdout); err != nil {
+	if _, err := io.Copy(output, reader); err != nil {
 		return fmt.Errorf("copy %v stdout: %v", catFile.Args, err)
 	}