Prometheus metrics for multipart file extraction

internal/upload/rewrite.go

+package upload
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"mime/multipart"
+	"net/http"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	multipartUploadRequests = prometheus.NewCounter(
+		prometheus.CounterOpts{
+
+			Name: "gitlab_workhorse_multipart_upload_requests",
+			Help: "How many multipart upload requests have been processed by gitlab-workhorse.",
+		},
+	)
+
+	multipartFileUploadBytes = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "gitlab_workhorse_multipart_upload_bytes",
+			Help: "How many disk bytes of multipart file parts have been written by gitlab-workhorse.",
+		},
+	)
+
+	multipartFiles = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "gitlab_workhorse_multipart_upload_files",
+			Help: "How many multipart file parts have been processed by gitlab-workhorse.",
+		},
+	)
+)
+
+func init() {
+	prometheus.MustRegister(multipartUploadRequests)
+	prometheus.MustRegister(multipartFileUploadBytes)
+	prometheus.MustRegister(multipartFiles)
+}
+
+func rewriteFormFilesFromMultipart(r *http.Request, writer *multipart.Writer, tempPath string, filter MultipartFormProcessor) (cleanup func(), err error) {
+	// Create multipart reader
+	reader, err := r.MultipartReader()
+	if err != nil {
+		if err == http.ErrNotMultipart {
+			// We want to be able to recognize http.ErrNotMultipart elsewhere so no fmt.Errorf
+			return nil, http.ErrNotMultipart
+		}
+		return nil, fmt.Errorf("get multipart reader: %v", err)
+	}
+
+	multipartUploadRequests.Inc()
+
+	var directories []string
+
+	cleanup = func() {
+		for _, dir := range directories {
+			os.RemoveAll(dir)
+		}
+	}
+
+	// Execute cleanup in case of failure
+	defer func() {
+		if err != nil {
+			cleanup()
+		}
+	}()
+
+	for {
+		p, err := reader.NextPart()
+		if err == io.EOF {
+			break
+		}
+
+		name := p.FormName()
+		if name == "" {
+			continue
+		}
+
+		// Copy form field
+		if filename := p.FileName(); filename != "" {
+			multipartFiles.Inc()
+
+			if strings.Contains(filename, "/") || filename == "." || filename == ".." {
+				return cleanup, fmt.Errorf("illegal filename: %q", filename)
+			}
+
+			// Create temporary directory where the uploaded file will be stored
+			if err := os.MkdirAll(tempPath, 0700); err != nil {
+				return cleanup, fmt.Errorf("mkdir for tempfile: %v", err)
+			}
+
+			tempDir, err := ioutil.TempDir(tempPath, "multipart-")
+			if err != nil {
+				return cleanup, fmt.Errorf("create tempdir: %v", err)
+			}
+			directories = append(directories, tempDir)
+
+			file, err := os.OpenFile(path.Join(tempDir, filename), os.O_WRONLY|os.O_CREATE, 0600)
+			if err != nil {
+				return cleanup, fmt.Errorf("rewriteFormFilesFromMultipart: temp file: %v", err)
+			}
+			defer file.Close()
+
+			// Add file entry
+			writer.WriteField(name+".path", file.Name())
+			writer.WriteField(name+".name", filename)
+
+			written, err := io.Copy(file, p)
+			if err != nil {
+				return cleanup, fmt.Errorf("copy from multipart to tempfile: %v", err)
+			}
+			multipartFileUploadBytes.Add(float64(written))
+
+			file.Close()
+
+			if err := filter.ProcessFile(name, file.Name(), writer); err != nil {
+				return cleanup, err
+			}
+		} else {
+			np, err := writer.CreatePart(p.Header)
+			if err != nil {
+				return cleanup, fmt.Errorf("create multipart field: %v", err)
+			}
+
+			_, err = io.Copy(np, p)
+			if err != nil {
+				return cleanup, fmt.Errorf("duplicate multipart field: %v", err)
+			}
+
+			if err := filter.ProcessField(name, writer); err != nil {
+				return cleanup, fmt.Errorf("process multipart field: %v", err)
+			}
+		}
+	}
+	return cleanup, nil
+}

internal/upload/uploads.go

@@ -3,13 +3,9 @@ package upload
 import (
 	"bytes"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"mime/multipart"
 	"net/http"
-	"os"
-	"path"
-	"strings"
 
 	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
 )
@@ -21,99 +17,6 @@ type MultipartFormProcessor interface {
 	Finalize() error
 }
 
-func rewriteFormFilesFromMultipart(r *http.Request, writer *multipart.Writer, tempPath string, filter MultipartFormProcessor) (cleanup func(), err error) {
-	// Create multipart reader
-	reader, err := r.MultipartReader()
-	if err != nil {
-		if err == http.ErrNotMultipart {
-			// We want to be able to recognize http.ErrNotMultipart elsewhere so no fmt.Errorf
-			return nil, http.ErrNotMultipart
-		}
-		return nil, fmt.Errorf("get multipart reader: %v", err)
-	}
-
-	var directories []string
-
-	cleanup = func() {
-		for _, dir := range directories {
-			os.RemoveAll(dir)
-		}
-	}
-
-	// Execute cleanup in case of failure
-	defer func() {
-		if err != nil {
-			cleanup()
-		}
-	}()
-
-	for {
-		p, err := reader.NextPart()
-		if err == io.EOF {
-			break
-		}
-
-		name := p.FormName()
-		if name == "" {
-			continue
-		}
-
-		// Copy form field
-		if filename := p.FileName(); filename != "" {
-			if strings.Contains(filename, "/") || filename == "." || filename == ".." {
-				return cleanup, fmt.Errorf("illegal filename: %q", filename)
-			}
-
-			// Create temporary directory where the uploaded file will be stored
-			if err := os.MkdirAll(tempPath, 0700); err != nil {
-				return cleanup, fmt.Errorf("mkdir for tempfile: %v", err)
-			}
-
-			tempDir, err := ioutil.TempDir(tempPath, "multipart-")
-			if err != nil {
-				return cleanup, fmt.Errorf("create tempdir: %v", err)
-			}
-			directories = append(directories, tempDir)
-
-			file, err := os.OpenFile(path.Join(tempDir, filename), os.O_WRONLY|os.O_CREATE, 0600)
-			if err != nil {
-				return cleanup, fmt.Errorf("rewriteFormFilesFromMultipart: temp file: %v", err)
-			}
-			defer file.Close()
-
-			// Add file entry
-			writer.WriteField(name+".path", file.Name())
-			writer.WriteField(name+".name", filename)
-
-			_, err = io.Copy(file, p)
-			if err != nil {
-				return cleanup, fmt.Errorf("copy from multipart to tempfile: %v", err)
-			}
-
-			file.Close()
-
-			if err := filter.ProcessFile(name, file.Name(), writer); err != nil {
-				return cleanup, err
-			}
-		} else {
-			np, err := writer.CreatePart(p.Header)
-			if err != nil {
-				return cleanup, fmt.Errorf("create multipart field: %v", err)
-			}
-
-			_, err = io.Copy(np, p)
-			if err != nil {
-				return cleanup, fmt.Errorf("duplicate multipart field: %v", err)
-			}
-
-			if err := filter.ProcessField(name, writer); err != nil {
-				return cleanup, fmt.Errorf("process multipart field: %v", err)
-			}
-		}
-	}
-	return cleanup, nil
-}
-
 func HandleFileUploads(w http.ResponseWriter, r *http.Request, h http.Handler, tempPath string, filter MultipartFormProcessor) {
 	if tempPath == "" {
 		helper.Fail500(w, r, fmt.Errorf("handleFileUploads: tempPath empty"))