Object Store direct upload

internal/api/api.go

@@ -68,7 +68,12 @@ func NewAPI(myURL *url.URL, version string, roundTripper *badgateway.RoundTrippe
 type HandleFunc func(http.ResponseWriter, *http.Request, *Response)
 
 type RemoteObjectStore struct {
-	// StoreURL is the temporary URL to which upload the first found file
+	// GetURL is not used in gitlab-workhorse. We pass it back to gitlab-rails
+	// later for symmetry with the 'store upload in tempfile' approach.
+	GetURL string
+	// DeleteURL is a presigned S3 RemoveObject URL
+	DeleteURL string
+	// StoreURL is the temporary presigned S3 PutObject URL to which upload the first found file
 	StoreURL string
 	// ObjectID is a unique identifier of object storage upload
 	ObjectID string
@@ -90,8 +95,8 @@ type Response struct {
 	// RepoPath is the full path on disk to the Git repository the request is
 	// about
 	RepoPath string
-	// StoreLFSPath is provided by the GitLab Rails application
-	// to mark where the tmp file should be placed
+	// StoreLFSPath is provided by the GitLab Rails application to mark where the tmp file should be placed.
+	// This field is deprecated. GitLab will use TempPath instead
 	StoreLFSPath string
 	// LFS object id
 	LfsOid string

internal/artifacts/artifacts_store.go

@@ -4,126 +4,28 @@ import (
 	"context"
 	"fmt"
 	"mime/multipart"
-	"net/http"
-	"os"
-	"time"
 
-	"github.com/prometheus/client_golang/prometheus"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/filestore"
 )
 
-var (
-	DefaultObjectStoreTimeoutSeconds = 360
-)
-
-var (
-	objectStorageUploadRequests = prometheus.NewCounterVec(
-		prometheus.CounterOpts{
-			Name: "gitlab_workhorse_object_storage_upload_requests",
-			Help: "How many object storage requests have been processed",
-		},
-		[]string{"status"},
-	)
-	objectStorageUploadsOpen = prometheus.NewGauge(
-		prometheus.GaugeOpts{
-			Name: "gitlab_workhorse_object_storage_upload_open",
-			Help: "Describes many object storage requests are open now",
-		},
-	)
-	objectStorageUploadBytes = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "gitlab_workhorse_object_storage_upload_bytes",
-			Help: "How many bytes were sent to object storage",
-		},
-	)
-	objectStorageUploadTime = prometheus.NewHistogram(
-		prometheus.HistogramOpts{
-			Name:    "gitlab_workhorse_object_storage_upload_time",
-			Help:    "How long it took to upload objects",
-			Buckets: objectStorageUploadTimeBuckets,
-		})
-
-	objectStorageUploadRequestsFileFailed      = objectStorageUploadRequests.WithLabelValues("file-failed")
-	objectStorageUploadRequestsRequestFailed   = objectStorageUploadRequests.WithLabelValues("request-failed")
-	objectStorageUploadRequestsInvalidStatus   = objectStorageUploadRequests.WithLabelValues("invalid-status")
-	objectStorageUploadRequestsSucceeded       = objectStorageUploadRequests.WithLabelValues("succeeded")
-	objectStorageUploadRequestsMultipleUploads = objectStorageUploadRequests.WithLabelValues("multiple-uploads")
-
-	objectStorageUploadTimeBuckets = []float64{.1, .25, .5, 1, 2.5, 5, 10, 25, 50, 100}
-)
-
-func init() {
-	prometheus.MustRegister(
-		objectStorageUploadRequests,
-		objectStorageUploadsOpen,
-		objectStorageUploadBytes)
-}
-
 func (a *artifactsUploadProcessor) storeFile(ctx context.Context, formName, fileName string, writer *multipart.Writer) error {
-	if a.ObjectStore.StoreURL == "" {
+	if !a.opts.IsRemote() {
 		return nil
 	}
 
 	if a.stored {
-		objectStorageUploadRequestsMultipleUploads.Inc()
 		return nil
 	}
 
-	started := time.Now()
-	defer func() {
-		objectStorageUploadTime.Observe(time.Since(started).Seconds())
-	}()
-
-	file, err := os.Open(fileName)
-	if err != nil {
-		objectStorageUploadRequestsFileFailed.Inc()
-		return err
-	}
-	defer file.Close()
-
-	fi, err := file.Stat()
+	fh, err := filestore.SaveFileFromDisk(ctx, fileName, a.opts)
 	if err != nil {
-		objectStorageUploadRequestsFileFailed.Inc()
-		return err
+		return fmt.Errorf("Uploading to object store failed. %s", err)
 	}
 
-	req, err := http.NewRequest("PUT", a.ObjectStore.StoreURL, file)
-	if err != nil {
-		objectStorageUploadRequestsRequestFailed.Inc()
-		return fmt.Errorf("PUT %q: %v", a.ObjectStore.StoreURL, err)
-	}
-	req.Header.Set("Content-Type", "application/octet-stream")
-	req.ContentLength = fi.Size()
-
-	objectStorageUploadsOpen.Inc()
-	defer objectStorageUploadsOpen.Dec()
-
-	timeout := DefaultObjectStoreTimeoutSeconds
-	if a.ObjectStore.Timeout != 0 {
-		timeout = a.ObjectStore.Timeout
-	}
-
-	ctx2, cancelFn := context.WithTimeout(ctx, time.Duration(timeout)*time.Second)
-	defer cancelFn()
-	req = req.WithContext(ctx2)
-
-	resp, err := http.DefaultClient.Do(req)
-	if err != nil {
-		objectStorageUploadRequestsRequestFailed.Inc()
-		return fmt.Errorf("PUT request %q: %v", a.ObjectStore.StoreURL, err)
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != http.StatusOK {
-		objectStorageUploadRequestsInvalidStatus.Inc()
-		return fmt.Errorf("PUT request %v returned: %d %s", a.ObjectStore.StoreURL, resp.StatusCode, resp.Status)
+	for field, value := range fh.GitLabFinalizeFields(formName) {
+		writer.WriteField(field, value)
 	}
 
-	writer.WriteField(formName+".store_url", a.ObjectStore.StoreURL)
-	writer.WriteField(formName+".object_id", a.ObjectStore.ObjectID)
-
-	objectStorageUploadRequestsSucceeded.Inc()
-	objectStorageUploadBytes.Add(float64(fi.Size()))
-
 	// Allow to upload only once using given credentials
 	a.stored = true
 	return nil

internal/artifacts/artifacts_store_test.go

@@ -3,6 +3,8 @@ package artifacts
 import (
 	"archive/zip"
 	"bytes"
+	"crypto/md5"
+	"encoding/hex"
 	"fmt"
 	"io/ioutil"
 	"mime/multipart"
@@ -19,14 +21,21 @@ import (
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/testhelper"
 )
 
-func createTestZipArchive(t *testing.T) []byte {
+func createTestZipArchive(t *testing.T) (data []byte, md5Hash string) {
 	var buffer bytes.Buffer
 	archive := zip.NewWriter(&buffer)
 	fileInArchive, err := archive.Create("test.file")
 	require.NoError(t, err)
 	fmt.Fprint(fileInArchive, "test")
 	archive.Close()
-	return buffer.Bytes()
+	data = buffer.Bytes()
+
+	hasher := md5.New()
+	hasher.Write(data)
+	hexHash := hasher.Sum(nil)
+	md5Hash = hex.EncodeToString(hexHash)
+
+	return data, md5Hash
 }
 
 func createTestMultipartForm(t *testing.T, data []byte) (bytes.Buffer, string) {
@@ -46,7 +55,7 @@ func TestUploadHandlerSendingToExternalStorage(t *testing.T) {
 	}
 	defer os.RemoveAll(tempPath)
 
-	archiveData := createTestZipArchive(t)
+	archiveData, md5 := createTestZipArchive(t)
 	contentBuffer, contentType := createTestMultipartForm(t, archiveData)
 
 	storeServerCalled := 0
@@ -59,6 +68,7 @@ func TestUploadHandlerSendingToExternalStorage(t *testing.T) {
 		require.Equal(t, archiveData, receivedData)
 
 		storeServerCalled++
+		w.Header().Set("ETag", md5)
 		w.WriteHeader(200)
 	})
 
@@ -78,6 +88,7 @@ func TestUploadHandlerSendingToExternalStorage(t *testing.T) {
 		ObjectStore: api.RemoteObjectStore{
 			StoreURL: storeServer.URL + "/url/put",
 			ObjectID: "store-id",
+			GetURL:   storeServer.URL + "/store-id",
 		},
 	}
 
@@ -112,7 +123,7 @@ func TestUploadHandlerSendingToExternalStorageAndStorageServerUnreachable(t *tes
 	ts := testArtifactsUploadServer(t, authResponse, responseProcessor)
 	defer ts.Close()
 
-	archiveData := createTestZipArchive(t)
+	archiveData, _ := createTestZipArchive(t)
 	contentBuffer, contentType := createTestMultipartForm(t, archiveData)
 
 	response := testUploadArtifacts(contentType, &contentBuffer, t, ts)
@@ -141,7 +152,7 @@ func TestUploadHandlerSendingToExternalStorageAndInvalidURLIsUsed(t *testing.T)
 	ts := testArtifactsUploadServer(t, authResponse, responseProcessor)
 	defer ts.Close()
 
-	archiveData := createTestZipArchive(t)
+	archiveData, _ := createTestZipArchive(t)
 	contentBuffer, contentType := createTestMultipartForm(t, archiveData)
 
 	response := testUploadArtifacts(contentType, &contentBuffer, t, ts)
@@ -182,7 +193,7 @@ func TestUploadHandlerSendingToExternalStorageAndItReturnsAnError(t *testing.T)
 	ts := testArtifactsUploadServer(t, authResponse, responseProcessor)
 	defer ts.Close()
 
-	archiveData := createTestZipArchive(t)
+	archiveData, _ := createTestZipArchive(t)
 	contentBuffer, contentType := createTestMultipartForm(t, archiveData)
 
 	response := testUploadArtifacts(contentType, &contentBuffer, t, ts)
@@ -226,7 +237,7 @@ func TestUploadHandlerSendingToExternalStorageAndSupportRequestTimeout(t *testin
 	ts := testArtifactsUploadServer(t, authResponse, responseProcessor)
 	defer ts.Close()
 
-	archiveData := createTestZipArchive(t)
+	archiveData, _ := createTestZipArchive(t)
 	contentBuffer, contentType := createTestMultipartForm(t, archiveData)
 
 	response := testUploadArtifacts(contentType, &contentBuffer, t, ts)

internal/artifacts/artifacts_upload.go

@@ -12,14 +12,14 @@ import (
 	"syscall"
 
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/api"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/filestore"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/upload"
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/zipartifacts"
 )
 
 type artifactsUploadProcessor struct {
-	TempPath     string
-	ObjectStore  api.RemoteObjectStore
+	opts         *filestore.SaveFileOpts
 	metadataFile string
 	stored       bool
 }
@@ -56,7 +56,7 @@ func (a *artifactsUploadProcessor) ProcessFile(ctx context.Context, formName, fi
 	}
 
 	// Create temporary file for metadata and store it's path
-	tempFile, err := ioutil.TempFile(a.TempPath, "metadata_")
+	tempFile, err := ioutil.TempFile(a.opts.LocalTempPath, "metadata_")
 	if err != nil {
 		return err
 	}
@@ -106,10 +106,7 @@ func UploadArtifacts(myAPI *api.API, h http.Handler) http.Handler {
 			return
 		}
 
-		mg := &artifactsUploadProcessor{
-			TempPath:    a.TempPath,
-			ObjectStore: a.ObjectStore,
-		}
+		mg := &artifactsUploadProcessor{opts: filestore.GetOpts(a)}
 		defer mg.Cleanup()
 
 		upload.HandleFileUploads(w, r, h, a.TempPath, mg)

internal/filestore/file_handler.go

@@ -8,15 +8,24 @@ import (
 	"io/ioutil"
 	"os"
 	"strconv"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/objectstore"
 )
 
+type MD5Error error
+type SizeError error
+
 // FileHandler represent a file that has been processed for upload
 // it may be either uploaded to an ObjectStore and/or saved on local path.
-// Remote upload is not yet implemented
 type FileHandler struct {
 	// LocalPath is the path on the disk where file has been stored
 	LocalPath string
 
+	// RemoteID is the objectID provided by GitLab Rails
+	RemoteID string
+	// RemoteURL is ObjectStore URL provided by GitLab Rails
+	RemoteURL string
+
 	// Size is the persisted file size
 	Size int64
 
@@ -55,6 +64,12 @@ func (fh *FileHandler) GitLabFinalizeFields(prefix string) map[string]string {
 	if fh.LocalPath != "" {
 		data[key("path")] = fh.LocalPath
 	}
+	if fh.RemoteURL != "" {
+		data[key("store_url")] = fh.RemoteURL
+	}
+	if fh.RemoteID != "" {
+		data[key("object_id")] = fh.RemoteID
+	}
 	data[key("size")] = strconv.FormatInt(fh.Size, 10)
 	for hashName, hash := range fh.hashes {
 		data[key(hashName)] = hash
@@ -66,7 +81,12 @@ func (fh *FileHandler) GitLabFinalizeFields(prefix string) map[string]string {
 // SaveFileFromReader persists the provided reader content to all the location specified in opts. A cleanup will be performed once ctx is Done
 // Make sure the provided context will not expire before finalizing upload with GitLab Rails.
 func SaveFileFromReader(ctx context.Context, reader io.Reader, size int64, opts *SaveFileOpts) (fh *FileHandler, err error) {
-	fh = &FileHandler{Name: opts.TempFilePrefix}
+	var object *objectstore.Object
+	fh = &FileHandler{
+		Name:      opts.TempFilePrefix,
+		RemoteID:  opts.RemoteID,
+		RemoteURL: opts.RemoteURL,
+	}
 	hashes := newMultiHash()
 	writers := []io.Writer{hashes.Writer}
 	defer func() {
@@ -77,6 +97,21 @@ func SaveFileFromReader(ctx context.Context, reader io.Reader, size int64, opts
 		}
 	}()
 
+	if opts.IsRemote() {
+		// Unknown ContentLength must be implemented in order to achieve Artifact Uploading
+		if size == -1 && !opts.isGoogleCloudStorage() {
+			// TODO add support for artifact upload to S3-compatible object storage
+			return nil, errors.New("Not implemented")
+		}
+
+		object, err = objectstore.NewObject(ctx, opts.PresignedPut, opts.PresignedDelete, opts.Timeout, size)
+		if err != nil {
+			return nil, err
+		}
+
+		writers = append(writers, object)
+	}
+
 	if opts.IsLocal() {
 		fileWriter, err := fh.uploadLocalFile(ctx, opts)
 		if err != nil {
@@ -97,11 +132,23 @@ func SaveFileFromReader(ctx context.Context, reader io.Reader, size int64, opts
 	}
 
 	if size != -1 && size != fh.Size {
-		return nil, fmt.Errorf("Expected %d bytes but got only %d", size, fh.Size)
+		return nil, SizeError(fmt.Errorf("Expected %d bytes but got only %d", size, fh.Size))
 	}
 
 	fh.hashes = hashes.finish()
 
+	if opts.IsRemote() {
+		// we need to close the writer in order to get ETag header
+		err = object.Close()
+		if err != nil {
+			return nil, err
+		}
+
+		if fh.MD5() != object.MD5() {
+			return nil, MD5Error(fmt.Errorf("expected md5 %s, got %s", fh.MD5(), object.MD5()))
+		}
+	}
+
 	return fh, err
 }
 
@@ -125,3 +172,19 @@ func (fh *FileHandler) uploadLocalFile(ctx context.Context, opts *SaveFileOpts)
 	fh.LocalPath = file.Name()
 	return file, nil
 }
+
+// SaveFileFromDisk open the local file fileName and calls SaveFileFromReader
+func SaveFileFromDisk(ctx context.Context, fileName string, opts *SaveFileOpts) (fh *FileHandler, err error) {
+	file, err := os.Open(fileName)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	fi, err := file.Stat()
+	if err != nil {
+		return nil, err
+	}
+
+	return SaveFileFromReader(ctx, file, fi.Size(), opts)
+}

internal/filestore/file_handler_test.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"path"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -13,64 +15,211 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/filestore"
-)
 
-// Some usefull const for testing purpose
-const (
-	// testContent an example textual content
-	testContent = "TEST OBJECT CONTENT"
-	// testSize is the testContent size
-	testSize = int64(len(testContent))
-	// testMD5 is testContent MD5 hash
-	testMD5 = "42d000eea026ee0760677e506189cb33"
-	// testSHA256 is testContent SHA256 hash
-	testSHA256 = "b0257e9e657ef19b15eed4fbba975bd5238d651977564035ef91cb45693647aa"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/objectstore/test"
 )
 
-func TestSaveFileFromReader(t *testing.T) {
+func assertFileGetsRemovedAsync(t *testing.T, filePath string) {
+	var err error
+
+	// Poll because the file removal is async
+	for i := 0; i < 100; i++ {
+		_, err = os.Stat(filePath)
+		if err != nil {
+			break
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	assert.True(t, os.IsNotExist(err), "File hasn't been deleted during cleanup")
+}
+
+func assertObjectStoreDeletedAsync(t *testing.T, expectedDeletes int, osStub *test.ObjectstoreStub) {
+	// Poll because the object removal is async
+	for i := 0; i < 100; i++ {
+		if osStub.DeletesCnt() == expectedDeletes {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	assert.Equal(t, expectedDeletes, osStub.DeletesCnt(), "Object not deleted")
+}
+
+func TestSaveFileWrongSize(t *testing.T) {
 	assert := assert.New(t)
 	require := require.New(t)
 
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
 	tmpFolder, err := ioutil.TempDir("", "workhorse-test-tmp")
 	require.NoError(err)
 	defer os.RemoveAll(tmpFolder)
 
+	opts := &filestore.SaveFileOpts{LocalTempPath: tmpFolder, TempFilePrefix: "test-file"}
+	fh, err := filestore.SaveFileFromReader(ctx, strings.NewReader(test.ObjectContent), test.ObjectSize+1, opts)
+	assert.Error(err)
+	_, isSizeError := err.(filestore.SizeError)
+	assert.True(isSizeError, "Should fail with SizeError")
+	assert.Nil(fh)
+}
+
+func TestSaveFromDiskNotExistingFile(t *testing.T) {
+	assert := assert.New(t)
+
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
+	fh, err := filestore.SaveFileFromDisk(ctx, "/I/do/not/exist", &filestore.SaveFileOpts{})
+	assert.Error(err, "SaveFileFromDisk should fail")
+	assert.True(os.IsNotExist(err), "Provided file should not exists")
+	assert.Nil(fh, "On error FileHandler should be nil")
+}
 
-	opts := &filestore.SaveFileOpts{LocalTempPath: tmpFolder, TempFilePrefix: "test-file"}
-	fh, err := filestore.SaveFileFromReader(ctx, strings.NewReader(testContent), testSize, opts)
-	assert.NoError(err)
-	require.NotNil(fh)
+func TestSaveFileWrongMD5(t *testing.T) {
+	assert := assert.New(t)
 
-	assert.NotEmpty(fh.LocalPath, "File hasn't been persisted on disk")
-	_, err = os.Stat(fh.LocalPath)
-	assert.NoError(err)
+	osStub, ts := test.StartObjectStoreWithCustomMD5(map[string]string{test.ObjectPath: "brokenMD5"})
+	defer ts.Close()
 
-	assert.Equal(testMD5, fh.MD5())
-	assert.Equal(testSHA256, fh.SHA256())
+	objectURL := ts.URL + test.ObjectPath
 
-	cancel()
-	time.Sleep(100 * time.Millisecond)
-	_, err = os.Stat(fh.LocalPath)
+	opts := &filestore.SaveFileOpts{
+		RemoteID:        "test-file",
+		RemoteURL:       objectURL,
+		PresignedPut:    objectURL + "?Signature=ASignature",
+		PresignedDelete: objectURL + "?Signature=AnotherSignature",
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	fh, err := filestore.SaveFileFromReader(ctx, strings.NewReader(test.ObjectContent), test.ObjectSize, opts)
+	assert.Nil(fh)
 	assert.Error(err)
-	assert.True(os.IsNotExist(err), "File hasn't been deleted during cleanup")
+	_, isMD5Error := err.(filestore.MD5Error)
+	assert.True(isMD5Error, "Should fail with MD5Error")
+	assert.Equal(1, osStub.PutsCnt(), "File not uploaded")
+
+	cancel() // this will trigger an async cleanup
+	assertObjectStoreDeletedAsync(t, 1, osStub)
 }
 
-func TestSaveFileWrongSize(t *testing.T) {
+func TestSaveFileFromDiskToLocalPath(t *testing.T) {
 	assert := assert.New(t)
 	require := require.New(t)
 
+	f, err := ioutil.TempFile("", "workhorse-test")
+	require.NoError(err)
+	defer os.Remove(f.Name())
+
+	_, err = fmt.Fprint(f, test.ObjectContent)
+	require.NoError(err)
+
+	tmpFolder, err := ioutil.TempDir("", "workhorse-test-tmp")
+	require.NoError(err)
+	defer os.RemoveAll(tmpFolder)
+
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
+	opts := &filestore.SaveFileOpts{LocalTempPath: tmpFolder}
+	fh, err := filestore.SaveFileFromDisk(ctx, f.Name(), opts)
+	assert.NoError(err)
+	require.NotNil(fh)
+
+	assert.NotEmpty(fh.LocalPath, "File not persisted on disk")
+	_, err = os.Stat(fh.LocalPath)
+	assert.NoError(err)
+}
+
+func TestSaveFile(t *testing.T) {
 	tmpFolder, err := ioutil.TempDir("", "workhorse-test-tmp")
-	require.NoError(err)
+	require.NoError(t, err)
 	defer os.RemoveAll(tmpFolder)
 
-	opts := &filestore.SaveFileOpts{LocalTempPath: tmpFolder, TempFilePrefix: "test-file"}
-	fh, err := filestore.SaveFileFromReader(ctx, strings.NewReader(testContent), testSize+1, opts)
-	assert.Error(err)
-	assert.EqualError(err, fmt.Sprintf("Expected %d bytes but got only %d", testSize+1, testSize))
-	assert.Nil(fh)
+	tests := []struct {
+		name   string
+		local  bool
+		remote bool
+	}{
+		{name: "Local only", local: true},
+		{name: "Remote only", remote: true},
+		{name: "Both", local: true, remote: true},
+	}
+
+	for _, spec := range tests {
+		t.Run(spec.name, func(t *testing.T) {
+			assert := assert.New(t)
+
+			var opts filestore.SaveFileOpts
+			var expectedDeletes, expectedPuts int
+
+			osStub, ts := test.StartObjectStore()
+			defer ts.Close()
+
+			if spec.remote {
+				objectURL := ts.URL + test.ObjectPath
+
+				opts.RemoteID = "test-file"
+				opts.RemoteURL = objectURL
+				opts.PresignedPut = objectURL + "?Signature=ASignature"
+				opts.PresignedDelete = objectURL + "?Signature=AnotherSignature"
+
+				expectedDeletes = 1
+				expectedPuts = 1
+			}
+
+			if spec.local {
+				opts.LocalTempPath = tmpFolder
+				opts.TempFilePrefix = "test-file"
+			}
+
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+
+			fh, err := filestore.SaveFileFromReader(ctx, strings.NewReader(test.ObjectContent), test.ObjectSize, &opts)
+			assert.NoError(err)
+			require.NotNil(t, fh)
+
+			assert.Equal(opts.RemoteID, fh.RemoteID)
+			assert.Equal(opts.RemoteURL, fh.RemoteURL)
+
+			if spec.local {
+				assert.NotEmpty(fh.LocalPath, "File not persisted on disk")
+				_, err := os.Stat(fh.LocalPath)
+				assert.NoError(err)
+
+				dir := path.Dir(fh.LocalPath)
+				assert.Equal(opts.LocalTempPath, dir)
+				filename := path.Base(fh.LocalPath)
+				beginsWithPrefix := strings.HasPrefix(filename, opts.TempFilePrefix)
+				assert.True(beginsWithPrefix, fmt.Sprintf("LocalPath filename %q do not begin with TempFilePrefix %q", filename, opts.TempFilePrefix))
+			} else {
+				assert.Empty(fh.LocalPath, "LocalPath must be empty for non local uploads")
+			}
+
+			assert.Equal(test.ObjectSize, fh.Size)
+			assert.Equal(test.ObjectMD5, fh.MD5())
+			assert.Equal(test.ObjectSHA256, fh.SHA256())
+
+			assert.Equal(expectedPuts, osStub.PutsCnt(), "ObjectStore PutObject count mismatch")
+			assert.Equal(0, osStub.DeletesCnt(), "File deleted too early")
+
+			cancel() // this will trigger an async cleanup
+			assertObjectStoreDeletedAsync(t, expectedDeletes, osStub)
+			assertFileGetsRemovedAsync(t, fh.LocalPath)
+
+			// checking generated fields
+			fields := fh.GitLabFinalizeFields("file")
+
+			assert.Equal(fh.Name, fields["file.name"])
+			assert.Equal(fh.LocalPath, fields["file.path"])
+			assert.Equal(fh.RemoteURL, fields["file.store_url"])
+			assert.Equal(fh.RemoteID, fields["file.object_id"])
+			assert.Equal(strconv.FormatInt(test.ObjectSize, 10), fields["file.size"])
+			assert.Equal(test.ObjectMD5, fields["file.md5"])
+			assert.Equal(test.ObjectSHA1, fields["file.sha1"])
+			assert.Equal(test.ObjectSHA256, fields["file.sha256"])
+			assert.Equal(test.ObjectSHA512, fields["file.sha512"])
+		})
+	}
 }

internal/filestore/save_file_opts.go

 package filestore
 
+import (
+	"net/url"
+	"time"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/api"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/objectstore"
+)
+
 // SaveFileOpts represents all the options available for saving a file to object store
 type SaveFileOpts struct {
 	// TempFilePrefix is the prefix used to create temporary local file
 	TempFilePrefix string
 	// LocalTempPath is the directory where to write a local copy of the file
 	LocalTempPath string
+	// RemoteID is the remote ObjectID provided by GitLab
+	RemoteID string
+	// RemoteURL is the final URL of the file
+	RemoteURL string
+	// PresignedPut is a presigned S3 PutObject compatible URL
+	PresignedPut string
+	// PresignedDelete is a presigned S3 DeleteObject compatible URL.
+	PresignedDelete string
+	// Timeout it the S3 operation timeout. If 0, objectstore.DefaultObjectStoreTimeout will be used
+	Timeout time.Duration
 }
 
 // IsLocal checks if the options require the writing of the file on disk
 func (s *SaveFileOpts) IsLocal() bool {
 	return s.LocalTempPath != ""
 }
+
+// IsRemote checks if the options requires a remote upload
+func (s *SaveFileOpts) IsRemote() bool {
+	return s.PresignedPut != ""
+}
+
+func (s *SaveFileOpts) isGoogleCloudStorage() bool {
+	if !s.IsRemote() {
+		return false
+	}
+
+	getURL, err := url.Parse(s.RemoteURL)
+	if err != nil {
+		return false
+	}
+
+	return objectstore.IsGoogleCloudStorage(getURL)
+}
+
+// GetOpts converts GitLab api.Response to a proper SaveFileOpts
+func GetOpts(apiResponse *api.Response) *SaveFileOpts {
+	timeout := time.Duration(apiResponse.ObjectStore.Timeout) * time.Second
+	if timeout == 0 {
+		timeout = objectstore.DefaultObjectStoreTimeout
+	}
+
+	return &SaveFileOpts{
+		LocalTempPath:   apiResponse.TempPath,
+		RemoteID:        apiResponse.ObjectStore.ObjectID,
+		RemoteURL:       apiResponse.ObjectStore.GetURL,
+		PresignedPut:    apiResponse.ObjectStore.StoreURL,
+		PresignedDelete: apiResponse.ObjectStore.DeleteURL,
+		Timeout:         timeout,
+	}
+}

internal/filestore/save_file_opts_test.go

+package filestore_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/api"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/filestore"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/objectstore"
+)
+
+func TestSaveFileOptsLocalAndRemote(t *testing.T) {
+	tests := []struct {
+		name          string
+		localTempPath string
+		presignedPut  string
+		isLocal       bool
+		isRemote      bool
+	}{
+		{
+			name:          "Only LocalTempPath",
+			localTempPath: "/tmp",
+			isLocal:       true,
+		},
+		{
+			name:          "Both paths",
+			localTempPath: "/tmp",
+			presignedPut:  "http://example.com",
+			isLocal:       true,
+			isRemote:      true,
+		},
+		{
+			name: "No paths",
+		},
+		{
+			name:         "Only remoteUrl",
+			presignedPut: "http://example.com",
+			isRemote:     true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+
+			assert := assert.New(t)
+
+			opts := filestore.SaveFileOpts{
+				LocalTempPath: test.localTempPath,
+				PresignedPut:  test.presignedPut,
+			}
+
+			assert.Equal(test.isLocal, opts.IsLocal(), "IsLocal() mismatch")
+			assert.Equal(test.isRemote, opts.IsRemote(), "IsRemote() mismatch")
+
+		})
+	}
+}
+
+func TestGetOpts(t *testing.T) {
+	assert := assert.New(t)
+	apiResponse := &api.Response{
+		TempPath: "/tmp",
+		ObjectStore: api.RemoteObjectStore{
+			Timeout:   10,
+			ObjectID:  "id",
+			GetURL:    "http://get",
+			StoreURL:  "http://store",
+			DeleteURL: "http://delete",
+		},
+	}
+
+	opts := filestore.GetOpts(apiResponse)
+
+	assert.Equal(apiResponse.TempPath, opts.LocalTempPath)
+	assert.Equal(time.Duration(apiResponse.ObjectStore.Timeout)*time.Second, opts.Timeout)
+	assert.Equal(apiResponse.ObjectStore.ObjectID, opts.RemoteID)
+	assert.Equal(apiResponse.ObjectStore.GetURL, opts.RemoteURL)
+	assert.Equal(apiResponse.ObjectStore.StoreURL, opts.PresignedPut)
+	assert.Equal(apiResponse.ObjectStore.DeleteURL, opts.PresignedDelete)
+}
+
+func TestGetOptsDefaultTimeout(t *testing.T) {
+	assert := assert.New(t)
+
+	opts := filestore.GetOpts(&api.Response{})
+
+	assert.Equal(objectstore.DefaultObjectStoreTimeout, opts.Timeout)
+}

internal/helper/helpers.go

@@ -18,7 +18,7 @@ import (
 
 const NginxResponseBufferHeader = "X-Accel-Buffering"
 
-var scrubRegexp = regexp.MustCompile(`(?i)([\?&]((?:private|authenticity|rss)[\-_]token)|X-AMZ-Signature)=[^&]*`)
+var scrubRegexp = regexp.MustCompile(`(?i)([\?&]((?:private|authenticity|rss)[\-_]token)|(?:X-AMZ-)?Signature)=[^&]*`)
 
 func Fail500(w http.ResponseWriter, r *http.Request, err error) {
 	http.Error(w, "Internal server error", 500)

internal/helper/helpers_test.go

@@ -130,6 +130,8 @@ func TestScrubURLParams(t *testing.T) {
 		"?X-AMZ-Signature=foo":                                              "?X-AMZ-Signature=[FILTERED]",
 		"&X-AMZ-Signature=foo":                                              "&X-AMZ-Signature=[FILTERED]",
 		"?x-amz-signature=foo":                                              "?x-amz-signature=[FILTERED]",
+		"&Signature=foo":                                                    "&Signature=[FILTERED]",
+		"?Signature=foo":                                                    "?Signature=[FILTERED]",
 	} {
 		after := ScrubURLParams(before)
 		assert.Equal(t, expected, after, "Scrubbing %q", before)

internal/lfs/lfs.go

@@ -23,10 +23,14 @@ func PutStore(a *api.API, h http.Handler) http.Handler {
 
 func handleStoreLFSObject(myAPI *api.API, h http.Handler) http.Handler {
 	return myAPI.PreAuthorizeHandler(func(w http.ResponseWriter, r *http.Request, a *api.Response) {
-		opts := &filestore.SaveFileOpts{
-			LocalTempPath:  a.StoreLFSPath,
-			TempFilePrefix: a.LfsOid,
+		opts := filestore.GetOpts(a)
+		opts.TempFilePrefix = a.LfsOid
+
+		// backward compatible api check - to be removed on next release
+		if a.StoreLFSPath != "" {
+			opts.LocalTempPath = a.StoreLFSPath
 		}
+		// end of backward compatible api check
 
 		fh, err := filestore.SaveFileFromReader(r.Context(), r.Body, r.ContentLength, opts)
 		if err != nil {
@@ -54,7 +58,11 @@ func handleStoreLFSObject(myAPI *api.API, h http.Handler) http.Handler {
 		r.Body = ioutil.NopCloser(strings.NewReader(body))
 		r.ContentLength = int64(len(body))
 		r.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-		r.Header.Set("X-GitLab-Lfs-Tmp", filepath.Base(fh.LocalPath))
+		// backward compatible API header - to be removed on next release
+		if opts.IsLocal() {
+			r.Header.Set("X-GitLab-Lfs-Tmp", filepath.Base(fh.LocalPath))
+		}
+		// end of backward compatible API header
 
 		// And proxy the request
 		h.ServeHTTP(w, r)

internal/objectstore/object.go

+package objectstore
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+)
+
+// DefaultObjectStoreTimeout is the timeout for ObjectStore PutObject api calls
+const DefaultObjectStoreTimeout = 360 * time.Second
+
+// httpTransport defines a http.Transport with values
+// that are more restrictive than for http.DefaultTransport,
+// they define shorter TLS Handshake, and more agressive connection closing
+// to prevent the connection hanging and reduce FD usage
+var httpTransport = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	DialContext: (&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 10 * time.Second,
+	}).DialContext,
+	MaxIdleConns:          2,
+	IdleConnTimeout:       30 * time.Second,
+	TLSHandshakeTimeout:   10 * time.Second,
+	ExpectContinueTimeout: 10 * time.Second,
+	ResponseHeaderTimeout: 30 * time.Second,
+}
+
+var httpClient = &http.Client{
+	Transport: httpTransport,
+}
+
+// IsGoogleCloudStorage checks if the provided URL is from Google Cloud Storage service
+func IsGoogleCloudStorage(u *url.URL) bool {
+	return strings.ToLower(u.Host) == "storage.googleapis.com"
+}
+
+type MissingContentLengthError error
+type StatusCodeError error
+
+// Object represents an object on a S3 compatible Object Store service.
+// It can be used as io.WriteCloser for uploading an object
+type Object struct {
+	// PutURL is a presigned URL for PutObject
+	PutURL string
+	// DeleteURL is a presigned URL for RemoveObject
+	DeleteURL string
+	// md5 is the checksum provided by the Object Store
+	md5 string
+
+	// writeCloser is the writer bound to the PutObject body
+	writeCloser io.WriteCloser
+	// uploadError is the last error occourred during upload
+	uploadError error
+	// ctx is the internal context bound to the upload request
+	ctx context.Context
+}
+
+// NewObject opens an HTTP connection to Object Store and returns an Object pointer that can be used for uploading.
+func NewObject(ctx context.Context, putURL, deleteURL string, timeout time.Duration, size int64) (*Object, error) {
+	started := time.Now()
+	o := &Object{
+		PutURL:    putURL,
+		DeleteURL: deleteURL,
+	}
+
+	pr, pw := io.Pipe()
+	o.writeCloser = pw
+
+	req, err := http.NewRequest(http.MethodPut, o.PutURL, pr)
+	if err != nil {
+		objectStorageUploadRequestsRequestFailed.Inc()
+		return nil, fmt.Errorf("PUT %q: %v", helper.ScrubURLParams(o.PutURL), err)
+	}
+	if size == -1 {
+		if !IsGoogleCloudStorage(req.URL) {
+			objectStorageUploadRequestsRequestFailed.Inc()
+			return nil, MissingContentLengthError(fmt.Errorf("Unknown Content-Length not allowed on %s", req.URL.Host))
+		}
+	} else {
+		req.ContentLength = size
+	}
+	req.Header.Set("Content-Type", "application/octet-stream")
+
+	if timeout == 0 {
+		timeout = DefaultObjectStoreTimeout
+	}
+
+	uploadCtx, cancelFn := context.WithTimeout(ctx, timeout)
+	o.ctx = uploadCtx
+
+	objectStorageUploadsOpen.Inc()
+
+	go func() {
+		// wait for the upload to finish
+		<-o.ctx.Done()
+		objectStorageUploadTime.Observe(time.Since(started).Seconds())
+
+		// wait for provided context to finish before performing cleanup
+		<-ctx.Done()
+		o.delete()
+	}()
+
+	go func() {
+		defer cancelFn()
+		defer objectStorageUploadsOpen.Dec()
+		defer pr.Close()
+
+		req = req.WithContext(o.ctx)
+
+		resp, err := httpClient.Do(req)
+		if err != nil {
+			objectStorageUploadRequestsRequestFailed.Inc()
+			o.uploadError = fmt.Errorf("PUT request %q: %v", helper.ScrubURLParams(o.PutURL), err)
+			return
+		}
+		defer resp.Body.Close()
+
+		if resp.StatusCode != http.StatusOK {
+			objectStorageUploadRequestsInvalidStatus.Inc()
+			o.uploadError = StatusCodeError(fmt.Errorf("PUT request %v returned: %s", helper.ScrubURLParams(o.PutURL), resp.Status))
+			return
+		}
+
+		o.extractMD5(resp.Header)
+	}()
+
+	return o, nil
+}
+
+// Write implements the standard io.Writer interface: it writes data to the PutObject body.
+func (o *Object) Write(p []byte) (int, error) {
+	return o.writeCloser.Write(p)
+}
+
+// Close implements the standard io.Closer interface: it closes the http client request.
+// This method will also wait for the connection to terminate and return any error occurred during the upload
+func (o *Object) Close() error {
+	if err := o.writeCloser.Close(); err != nil {
+		return err
+	}
+
+	<-o.ctx.Done()
+
+	return o.uploadError
+}
+
+// MD5 returns the md5sum of the uploaded returned by the Object Store provider via ETag Header.
+// This method will wait until upload context is done before returning.
+func (o *Object) MD5() string {
+	<-o.ctx.Done()
+
+	return o.md5
+}
+
+func (o *Object) extractMD5(h http.Header) {
+	etag := h.Get("ETag")
+	if etag != "" && etag[0] == '"' {
+		etag = etag[1 : len(etag)-1]
+	}
+	o.md5 = etag
+}
+
+func (o *Object) delete() {
+	if o.DeleteURL == "" {
+		return
+	}
+
+	<-o.ctx.Done()
+
+	req, err := http.NewRequest(http.MethodDelete, o.DeleteURL, nil)
+	if err != nil {
+		objectStorageUploadRequestsRequestFailed.Inc()
+		return
+	}
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		objectStorageUploadRequestsRequestFailed.Inc()
+		return
+	}
+	resp.Body.Close()
+}

internal/objectstore/object_test.go

+package objectstore_test
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/objectstore"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/objectstore/test"
+)
+
+const testTimeout = 10 * time.Second
+
+func testObjectUploadNoErrors(t *testing.T, useDeleteURL bool) {
+	assert := assert.New(t)
+
+	osStub, ts := test.StartObjectStore()
+	defer ts.Close()
+
+	objectURL := ts.URL + test.ObjectPath
+	var deleteURL string
+	if useDeleteURL {
+		deleteURL = objectURL
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	object, err := objectstore.NewObject(ctx, objectURL, deleteURL, testTimeout, test.ObjectSize)
+	require.NoError(t, err)
+
+	// copy data
+	n, err := io.Copy(object, strings.NewReader(test.ObjectContent))
+	assert.NoError(err)
+	assert.Equal(test.ObjectSize, n, "Uploaded file mismatch")
+
+	// close HTTP stream
+	err = object.Close()
+	assert.NoError(err)
+
+	// Checking MD5 extraction
+	assert.Equal(osStub.GetObjectMD5(test.ObjectPath), object.MD5())
+
+	// Checking cleanup
+	cancel()
+	assert.Equal(1, osStub.PutsCnt(), "Object hasn't been uploaded")
+
+	var expectedDeleteCnt int
+	if useDeleteURL {
+		expectedDeleteCnt = 1
+	}
+	// Poll because the object removal is async
+	for i := 0; i < 100; i++ {
+		if osStub.DeletesCnt() == expectedDeleteCnt {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	if useDeleteURL {
+		assert.Equal(1, osStub.DeletesCnt(), "Object hasn't been deleted")
+	} else {
+		assert.Equal(0, osStub.DeletesCnt(), "Object has been deleted")
+	}
+}
+
+func TestObjectUpload(t *testing.T) {
+	t.Run("with delete URL", func(t *testing.T) { testObjectUploadNoErrors(t, true) })
+	t.Run("without delete URL", func(t *testing.T) { testObjectUploadNoErrors(t, false) })
+}
+
+func TestObjectUpload404(t *testing.T) {
+	assert := assert.New(t)
+
+	ts := httptest.NewServer(http.NotFoundHandler())
+	defer ts.Close()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	objectURL := ts.URL + test.ObjectPath
+	object, err := objectstore.NewObject(ctx, objectURL, "", testTimeout, test.ObjectSize)
+	require.NoError(t, err)
+	_, err = io.Copy(object, strings.NewReader(test.ObjectContent))
+
+	assert.NoError(err)
+	err = object.Close()
+	assert.Error(err)
+	_, isStatusCodeError := err.(objectstore.StatusCodeError)
+	assert.True(isStatusCodeError, "Should fail with StatusCodeError")
+	assert.Contains(err.Error(), "404")
+}
+
+func TestUnknownSizeUpload(t *testing.T) {
+	assert := assert.New(t)
+
+	object, err := objectstore.NewObject(context.Background(), "http://example.com/bucket/object", "", 0, -1)
+	assert.Error(err)
+	_, isMissingContentLengthError := err.(objectstore.MissingContentLengthError)
+	assert.True(isMissingContentLengthError, "Should fail with MissingContentLengthError")
+	assert.Nil(object)
+}

internal/objectstore/prometheus.go

+package objectstore
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	objectStorageUploadRequests = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "gitlab_workhorse_object_storage_upload_requests",
+			Help: "How many object storage requests have been processed",
+		},
+		[]string{"status"},
+	)
+	objectStorageUploadsOpen = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "gitlab_workhorse_object_storage_upload_open",
+			Help: "Describes many object storage requests are open now",
+		},
+	)
+	objectStorageUploadBytes = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "gitlab_workhorse_object_storage_upload_bytes",
+			Help: "How many bytes were sent to object storage",
+		},
+	)
+	objectStorageUploadTime = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "gitlab_workhorse_object_storage_upload_time",
+			Help:    "How long it took to upload objects",
+			Buckets: objectStorageUploadTimeBuckets,
+		})
+
+	objectStorageUploadRequestsFileFailed      = objectStorageUploadRequests.WithLabelValues("file-failed")
+	objectStorageUploadRequestsRequestFailed   = objectStorageUploadRequests.WithLabelValues("request-failed")
+	objectStorageUploadRequestsInvalidStatus   = objectStorageUploadRequests.WithLabelValues("invalid-status")
+	objectStorageUploadRequestsSucceeded       = objectStorageUploadRequests.WithLabelValues("succeeded")
+	objectStorageUploadRequestsMultipleUploads = objectStorageUploadRequests.WithLabelValues("multiple-uploads")
+
+	objectStorageUploadTimeBuckets = []float64{.1, .25, .5, 1, 2.5, 5, 10, 25, 50, 100}
+)
+
+func init() {
+	prometheus.MustRegister(
+		objectStorageUploadRequests,
+		objectStorageUploadsOpen,
+		objectStorageUploadBytes)
+}

internal/objectstore/test/consts.go

+package test
+
+// Some usefull const for testing purpose
+const (
+	// ObjectContent an example textual content
+	ObjectContent = "TEST OBJECT CONTENT"
+	// ObjectSize is the ObjectContent size
+	ObjectSize = int64(len(ObjectContent))
+	// Objectpath is an example remote object path (including bucket name)
+	ObjectPath = "/bucket/object"
+	// ObjectMD5 is ObjectContent MD5 hash
+	ObjectMD5 = "42d000eea026ee0760677e506189cb33"
+	// ObjectSHA1 is ObjectContent SHA1 hash
+	ObjectSHA1 = "173cfd58c6b60cb910f68a26cbb77e3fc5017a6d"
+	// ObjectSHA256 is ObjectContent SHA256 hash
+	ObjectSHA256 = "b0257e9e657ef19b15eed4fbba975bd5238d651977564035ef91cb45693647aa"
+	// ObjectSHA512 is ObjectContent SHA512 hash
+	ObjectSHA512 = "51af8197db2047f7894652daa7437927bf831d5aa63f1b0b7277c4800b06f5e3057251f0e4c2d344ca8c2daf1ffc08a28dd3b2f5fe0e316d3fd6c3af58c34b97"
+)

internal/objectstore/test/objectstore_stub.go

+package test
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+)
+
+// ObjectstoreStub is a testing implementation of ObjectStore.
+// Instead of storing objects it will just save md5sum.
+type ObjectstoreStub struct {
+	// bucket contains md5sum of uploaded objects
+	bucket map[string]string
+	// overwriteMD5 contains overwrites for md5sum that should be return instead of the regular hash
+	overwriteMD5 map[string]string
+
+	puts    int
+	deletes int
+
+	m sync.Mutex
+}
+
+// StartObjectStore will start an ObjectStore stub
+func StartObjectStore() (*ObjectstoreStub, *httptest.Server) {
+	return StartObjectStoreWithCustomMD5(make(map[string]string))
+}
+
+// StartObjectStoreWithCustomMD5 will start an ObjectStore stub: md5Hashes contains overwrites for md5sum that should be return on PutObject
+func StartObjectStoreWithCustomMD5(md5Hashes map[string]string) (*ObjectstoreStub, *httptest.Server) {
+	os := &ObjectstoreStub{
+		bucket:       make(map[string]string),
+		overwriteMD5: make(map[string]string),
+	}
+
+	for k, v := range md5Hashes {
+		os.overwriteMD5[k] = v
+	}
+
+	return os, httptest.NewServer(os)
+}
+
+// PutsCnt counts PutObject invocations
+func (o *ObjectstoreStub) PutsCnt() int {
+	o.m.Lock()
+	defer o.m.Unlock()
+
+	return o.puts
+}
+
+// DeletesCnt counts DeleteObject invocation of a valid object
+func (o *ObjectstoreStub) DeletesCnt() int {
+	o.m.Lock()
+	defer o.m.Unlock()
+
+	return o.deletes
+}
+
+// GetObjectMD5 return the calculated MD5 of the object uploaded to path
+// it will return an empty string if no object has been uploaded on such path
+func (o *ObjectstoreStub) GetObjectMD5(path string) string {
+	o.m.Lock()
+	defer o.m.Unlock()
+
+	return o.bucket[path]
+}
+
+func (o *ObjectstoreStub) removeObject(w http.ResponseWriter, r *http.Request) {
+	o.m.Lock()
+	defer o.m.Unlock()
+
+	objectPath := r.URL.Path
+	if _, ok := o.bucket[objectPath]; ok {
+		o.deletes++
+		delete(o.bucket, objectPath)
+
+		w.WriteHeader(200)
+	} else {
+		w.WriteHeader(404)
+	}
+}
+
+func (o *ObjectstoreStub) putObject(w http.ResponseWriter, r *http.Request) {
+	o.m.Lock()
+	defer o.m.Unlock()
+
+	objectPath := r.URL.Path
+
+	etag, overwritten := o.overwriteMD5[objectPath]
+	if !overwritten {
+		hasher := md5.New()
+		io.Copy(hasher, r.Body)
+
+		checksum := hasher.Sum(nil)
+		etag = hex.EncodeToString(checksum)
+	}
+
+	o.puts++
+	o.bucket[objectPath] = etag
+
+	w.Header().Set("ETag", etag)
+	w.WriteHeader(200)
+}
+
+func (o *ObjectstoreStub) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Body != nil {
+		defer r.Body.Close()
+	}
+
+	fmt.Println("ObjectStore Stub:", r.Method, r.URL.Path)
+
+	switch r.Method {
+	case "DELETE":
+		o.removeObject(w, r)
+	case "PUT":
+		o.putObject(w, r)
+	default:
+		w.WriteHeader(404)
+	}
+}

internal/objectstore/test/objectstore_stub_test.go

+package test
+
+import (
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestObjectStoreStub(t *testing.T) {
+	assert := assert.New(t)
+	require := require.New(t)
+
+	stub, ts := StartObjectStore()
+	defer ts.Close()
+
+	assert.Equal(0, stub.PutsCnt())
+	assert.Equal(0, stub.DeletesCnt())
+
+	objectURL := ts.URL + ObjectPath
+
+	req, err := http.NewRequest(http.MethodPut, objectURL, strings.NewReader(ObjectContent))
+	require.NoError(err)
+
+	_, err = http.DefaultClient.Do(req)
+	require.NoError(err)
+
+	assert.Equal(1, stub.PutsCnt())
+	assert.Equal(0, stub.DeletesCnt())
+	assert.Equal(ObjectMD5, stub.GetObjectMD5(ObjectPath))
+
+	req, err = http.NewRequest(http.MethodDelete, objectURL, nil)
+	require.NoError(err)
+
+	_, err = http.DefaultClient.Do(req)
+	require.NoError(err)
+
+	assert.Equal(1, stub.PutsCnt())
+	assert.Equal(1, stub.DeletesCnt())
+}
+
+func TestObjectStoreStubDelete404(t *testing.T) {
+	assert := assert.New(t)
+	require := require.New(t)
+
+	stub, ts := StartObjectStore()
+	defer ts.Close()
+
+	objectURL := ts.URL + ObjectPath
+
+	req, err := http.NewRequest(http.MethodDelete, objectURL, nil)
+	require.NoError(err)
+
+	resp, err := http.DefaultClient.Do(req)
+	require.NoError(err)
+	assert.Equal(404, resp.StatusCode)
+
+	assert.Equal(0, stub.DeletesCnt())
+}