Move lfs handling into its separate file.

githandler.go

@@ -47,6 +47,9 @@ type gitRequest struct {
 	// CommitId is used do prevent race conditions between the 'time of check'
 	// in the GitLab Rails app and the 'time of use' in gitlab-workhorse.
 	CommitId string
+
+	// TODO: say something about this
+	StoreLFSPath string
 }
 
 // Routing table
@@ -60,13 +63,9 @@ var gitServices = [...]gitService{
 	gitService{"GET", "/repository/archive.tar.gz", handleGetArchive, "tar.gz"},
 	gitService{"GET", "/repository/archive.tar.bz2", handleGetArchive, "tar.bz2"},
 	gitService{"PUT", "/gitlab-lfs/objects", handleStoreLfsObject, "lfs-object-receive"},
+	gitService{"GET", "/gitlab-lfs/objects", handleRetreiveLfsObject, "lfs-object-upload"},
 }
 
-var (
-	errHashMismatch = errors.New("Content hash does not match OID")
-	errSizeMismatch = errors.New("Content size does not match")
-)
-
 func newGitHandler(authBackend string, authTransport http.RoundTripper) *gitHandler {
 	return &gitHandler{&http.Client{Transport: authTransport}, authBackend}
 }

lfs.go

+/*
+In this file we handle git lfs objects downloads and uploads
+*/
+
+package main
+
+import (
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+)
+
+var (
+	errHashMismatch = errors.New("Content hash does not match OID")
+	errSizeMismatch = errors.New("Content size does not match")
+)
+
+func handleStoreLfsObject(w http.ResponseWriter, r *gitRequest, rpc string) {
+	var body io.ReadCloser
+	var err error
+
+	urlPath := r.URL.Path
+	regExp := regexp.MustCompile(`([0-9a-f]{64})/([0-9]+)`)
+	matches := regExp.FindStringSubmatch(urlPath)
+
+	if matches == nil {
+		log.Printf("Found no object info in path: %s", urlPath)
+		return
+	}
+
+	oid := matches[1]
+	size := matches[2]
+	log.Printf("Found oid: %s and size: %s", oid, size)
+
+	path := filepath.Join(r.StoreLFSPath, transformKey(oid))
+	tmpPath := path + ".tmp"
+
+	// TODO try removing gzip, possibly not needed
+	// The client request body may have been gzipped.
+	if r.Header.Get("Content-Encoding") == "gzip" {
+		body, err = gzip.NewReader(r.Body)
+		if err != nil {
+			fail500(w, "Couldn't handle LFS upload request.", err)
+			return
+		}
+	} else {
+		body = r.Body
+	}
+	defer body.Close()
+
+	// TODO maybe set dir permissions to 700
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0750); err != nil {
+		fail500(w, "Couldn't create directory for storing LFS objects.", err)
+		return
+	}
+
+	// TODO use go library for creating TMP files
+	file, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_EXCL, 0640)
+	if err != nil {
+		fail500(w, "Couldn't open tmp file for writing.", err)
+		return
+	}
+	defer os.Remove(tmpPath)
+	defer file.Close()
+
+	hash := sha256.New()
+	hw := io.MultiWriter(hash, file)
+
+	written, err := io.Copy(hw, body)
+	if err != nil {
+		fail500(w, "Failed to save received LFS object.", err)
+		return
+	}
+	file.Close()
+
+	sizeInt, err := strconv.ParseInt(size, 10, 64)
+	if err != nil {
+		fail500(w, "Couldn't read size: ", err)
+		return
+	}
+
+	if written != sizeInt {
+		fail500(w, "Inconsistent size: ", errSizeMismatch)
+		return
+	}
+
+	shaStr := hex.EncodeToString(hash.Sum(nil))
+	if shaStr != oid {
+		fail500(w, "Inconsistent size: ", errSizeMismatch)
+		return
+	}
+
+	if err := os.Rename(tmpPath, path); err != nil {
+		fail500(w, "Failed to rename temporary LFS object.", err)
+		return
+	}
+
+	log.Printf("Received the LFS object from client, oid: %s", oid)
+
+	return
+}
+
+func handleRetreiveLfsObject(w http.ResponseWriter, r *gitRequest, rpc string) {
+	log.Printf("I should download %s", r)
+
+	urlPath := r.URL.Path
+	regExp := regexp.MustCompile(`([0-9a-f]{64})\z`)
+	oid := regExp.FindString(urlPath)
+
+	if len(oid) == 0 {
+		log.Printf("Found no object for download: %s", urlPath)
+		return
+	}
+
+	log.Printf("Found oid: %s", oid)
+	path := filepath.Join(r.StoreLFSPath, transformKey(oid))
+
+	content, err := os.Open(path)
+	if err != nil {
+		fail500(w, "Cannot get file: ", err)
+		return
+	}
+	defer content.Close()
+
+	io.Copy(w, content)
+
+	log.Printf("Sent the LFS object to client, oid: %s", oid)
+
+	return
+}
+
+func transformKey(key string) string {
+	if len(key) < 5 {
+		return key
+	}
+
+	return filepath.Join(key[0:2], key[2:4], key[4:len(key)])
+}