Add option to disable archive caching

gitaly_test.go

@@ -3,6 +3,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"math/rand"
 	"net"
 	"net/http"
@@ -448,19 +449,37 @@ func TestGetArchiveProxiedToGitalySuccessfully(t *testing.T) {
 	repoStorage := "default"
 	oid := "54fcc214b94e78d7a41a9a8fe6d87a5e59500e51"
 	repoRelativePath := "foo/bar.git"
-	archivePath := "my/path"
 	archivePrefix := "repo-1"
-	jsonParams := fmt.Sprintf(`{"GitalyServer":{"Address":"%s","Token":""},"GitalyRepository":{"storage_name":"%s","relative_path":"%s"},"ArchivePath":"%s","ArchivePrefix":"%s","CommitId":"%s"}`,
-		gitalyAddress, repoStorage, repoRelativePath, archivePath, archivePrefix, oid)
 	expectedBody := testhelper.GitalyGetArchiveResponseMock
 	archiveLength := len(expectedBody)
 
+	testCases := []struct {
+		archivePath   string
+		cacheDisabled bool
+	}{
+		{archivePath: path.Join(scratchDir, "my/path"), cacheDisabled: false},
+		{archivePath: "/var/empty/my/path", cacheDisabled: true},
+	}
+
+	for _, tc := range testCases {
+		jsonParams := fmt.Sprintf(`{"GitalyServer":{"Address":"%s","Token":""},"GitalyRepository":{"storage_name":"%s","relative_path":"%s"},"ArchivePath":"%s","ArchivePrefix":"%s","CommitId":"%s","DisableCache":%v}`,
+			gitalyAddress, repoStorage, repoRelativePath, tc.archivePath, archivePrefix, oid, tc.cacheDisabled)
 		resp, body, err := doSendDataRequest("/archive.tar.gz", "git-archive", jsonParams)
 		require.NoError(t, err)
 
 		assert.Equal(t, 200, resp.StatusCode, "GET %q: status code", resp.Request.URL)
 		assert.Equal(t, expectedBody, string(body), "GET %q: response body", resp.Request.URL)
 		assert.Equal(t, archiveLength, len(body), "GET %q: body size", resp.Request.URL)
+
+		if tc.cacheDisabled {
+			_, err := os.Stat(tc.archivePath)
+			require.True(t, os.IsNotExist(err), "expected 'does not exist', got: %v", err)
+		} else {
+			cachedArchive, err := ioutil.ReadFile(tc.archivePath)
+			require.NoError(t, err)
+			require.Equal(t, expectedBody, string(cachedArchive))
+		}
+	}
 }
 
 func TestGetArchiveProxiedToGitalyInterruptedStream(t *testing.T) {

internal/git/archive.go

@@ -30,6 +30,7 @@ type archiveParams struct {
 	CommitId         string
 	GitalyServer     gitaly.Server
 	GitalyRepository pb.Repository
+	DisableCache     bool
 }
 
 var (
@@ -61,9 +62,12 @@ func (a *archive) Inject(w http.ResponseWriter, r *http.Request, sendData string
 		return
 	}
 
+	cacheEnabled := !params.DisableCache
 	archiveFilename := path.Base(params.ArchivePath)
 
-	if cachedArchive, err := os.Open(params.ArchivePath); err == nil {
+	if cacheEnabled {
+		cachedArchive, err := os.Open(params.ArchivePath)
+		if err == nil {
 			defer cachedArchive.Close()
 			gitArchiveCache.WithLabelValues("hit").Inc()
 			setArchiveHeaders(w, format, archiveFilename)
@@ -73,20 +77,26 @@ func (a *archive) Inject(w http.ResponseWriter, r *http.Request, sendData string
 			http.ServeContent(w, r, "", time.Unix(0, 0), cachedArchive)
 			return
 		}
+	}
 
 	gitArchiveCache.WithLabelValues("miss").Inc()
 
+	var tempFile *os.File
+	var err error
+
+	if cacheEnabled {
 		// We assume the tempFile has a unique name so that concurrent requests are
 		// safe. We create the tempfile in the same directory as the final cached
 		// archive we want to create so that we can use an atomic link(2) operation
 		// to finalize the cached archive.
-	tempFile, err := prepareArchiveTempfile(path.Dir(params.ArchivePath), archiveFilename)
+		tempFile, err = prepareArchiveTempfile(path.Dir(params.ArchivePath), archiveFilename)
 		if err != nil {
 			helper.Fail500(w, r, fmt.Errorf("SendArchive: create tempfile: %v", err))
 			return
 		}
 		defer tempFile.Close()
 		defer os.Remove(tempFile.Name())
+	}
 
 	var archiveReader io.Reader
 	if params.GitalyServer.Address != "" {
@@ -103,7 +113,10 @@ func (a *archive) Inject(w http.ResponseWriter, r *http.Request, sendData string
 		return
 	}
 
-	reader := io.TeeReader(archiveReader, tempFile)
+	reader := archiveReader
+	if cacheEnabled {
+		reader = io.TeeReader(archiveReader, tempFile)
+	}
 
 	// Start writing the response
 	setArchiveHeaders(w, format, archiveFilename)
@@ -113,10 +126,13 @@ func (a *archive) Inject(w http.ResponseWriter, r *http.Request, sendData string
 		return
 	}
 
-	if err := finalizeCachedArchive(tempFile, params.ArchivePath); err != nil {
+	if cacheEnabled {
+		err := finalizeCachedArchive(tempFile, params.ArchivePath)
+		if err != nil {
 			helper.LogError(r, fmt.Errorf("SendArchive: finalize cached archive: %v", err))
 			return
 		}
+	}
 }
 
 func handleArchiveWithGitaly(r *http.Request, params archiveParams, format pb.GetArchiveRequest_Format) (io.Reader, error) {