X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/62edf6175986bf062076b42f89ef472446d0d18e..79bce4a71a58118a9003882e0ca9bbfb9d2957a9:/services/keep-web/s3.go

diff --git a/services/keep-web/s3.go b/services/keep-web/s3.go
index c774275407..52cfede466 100644
--- a/services/keep-web/s3.go
+++ b/services/keep-web/s3.go
@@ -68,7 +68,7 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
 	objectNameGiven := strings.Count(strings.TrimSuffix(r.URL.Path, "/"), "/") > 1
 
 	switch {
-	case r.Method == "GET" && !objectNameGiven:
+	case r.Method == http.MethodGet && !objectNameGiven:
 		// Path is "/{uuid}" or "/{uuid}/", has no object name
 		if _, ok := r.URL.Query()["versioning"]; ok {
 			// GetBucketVersioning
@@ -80,7 +80,7 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
 			h.s3list(w, r, fs)
 		}
 		return true
-	case r.Method == "GET" || r.Method == "HEAD":
+	case r.Method == http.MethodGet || r.Method == http.MethodHead:
 		fspath := "/by_id" + r.URL.Path
 		fi, err := fs.Stat(fspath)
 		if r.Method == "HEAD" && !objectNameGiven {
@@ -110,7 +110,7 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
 		r.URL.Path = fspath
 		http.FileServer(fs).ServeHTTP(w, &r)
 		return true
-	case r.Method == "PUT":
+	case r.Method == http.MethodPut:
 		if !objectNameGiven {
 			http.Error(w, "missing object name in PUT request", http.StatusBadRequest)
 			return true
@@ -205,6 +205,54 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
 		}
 		w.WriteHeader(http.StatusOK)
 		return true
+	case r.Method == http.MethodDelete:
+		if !objectNameGiven || r.URL.Path == "/" {
+			http.Error(w, "missing object name in DELETE request", http.StatusBadRequest)
+			return true
+		}
+		fspath := "by_id" + r.URL.Path
+		if strings.HasSuffix(fspath, "/") {
+			fspath = strings.TrimSuffix(fspath, "/")
+			fi, err := fs.Stat(fspath)
+			if os.IsNotExist(err) {
+				w.WriteHeader(http.StatusNoContent)
+				return true
+			} else if err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return true
+			} else if !fi.IsDir() {
+				// if "foo" exists and is a file, then
+				// "foo/" doesn't exist, so we say
+				// delete was successful.
+				w.WriteHeader(http.StatusNoContent)
+				return true
+			}
+		} else if fi, err := fs.Stat(fspath); err == nil && fi.IsDir() {
+			// if "foo" is a dir, it is visible via S3
+			// only as "foo/", not "foo" -- so we leave
+			// the dir alone and return 204 to indicate
+			// that "foo" does not exist.
+			w.WriteHeader(http.StatusNoContent)
+			return true
+		}
+		err = fs.Remove(fspath)
+		if os.IsNotExist(err) {
+			w.WriteHeader(http.StatusNoContent)
+			return true
+		}
+		if err != nil {
+			err = fmt.Errorf("rm failed: %w", err)
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return true
+		}
+		err = fs.Sync()
+		if err != nil {
+			err = fmt.Errorf("sync failed: %w", err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return true
+		}
+		w.WriteHeader(http.StatusNoContent)
+		return true
 	default:
 		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
 		return true
@@ -300,12 +348,30 @@ func (h *handler) s3list(w http.ResponseWriter, r *http.Request, fs arvados.Cust
 		walkpath = ""
 	}
 
-	resp := s3.ListResp{
-		Name:      strings.SplitN(r.URL.Path[1:], "/", 2)[0],
-		Prefix:    params.prefix,
-		Delimiter: params.delimiter,
-		Marker:    params.marker,
-		MaxKeys:   params.maxKeys,
+	type commonPrefix struct {
+		Prefix string
+	}
+	type listResp struct {
+		XMLName string `xml:"http://s3.amazonaws.com/doc/2006-03-01/ ListBucketResult"`
+		s3.ListResp
+		// s3.ListResp marshals an empty tag when
+		// CommonPrefixes is nil, which confuses some clients.
+		// Fix by using this nested struct instead.
+		CommonPrefixes []commonPrefix
+		// Similarly, we need omitempty here, because an empty
+		// tag confuses some clients (e.g.,
+		// github.com/aws/aws-sdk-net never terminates its
+		// paging loop).
+		NextMarker string `xml:"NextMarker,omitempty"`
+	}
+	resp := listResp{
+		ListResp: s3.ListResp{
+			Name:      strings.SplitN(r.URL.Path[1:], "/", 2)[0],
+			Prefix:    params.prefix,
+			Delimiter: params.delimiter,
+			Marker:    params.marker,
+			MaxKeys:   params.maxKeys,
+		},
 	}
 	commonPrefixes := map[string]bool{}
 	err := walkFS(fs, strings.TrimSuffix(bucketdir+"/"+walkpath, "/"), true, func(path string, fi os.FileInfo) error {
@@ -387,18 +453,15 @@ func (h *handler) s3list(w http.ResponseWriter, r *http.Request, fs arvados.Cust
 		return
 	}
 	if params.delimiter != "" {
+		resp.CommonPrefixes = make([]commonPrefix, 0, len(commonPrefixes))
 		for prefix := range commonPrefixes {
-			resp.CommonPrefixes = append(resp.CommonPrefixes, prefix)
-			sort.Strings(resp.CommonPrefixes)
+			resp.CommonPrefixes = append(resp.CommonPrefixes, commonPrefix{prefix})
 		}
+		sort.Slice(resp.CommonPrefixes, func(i, j int) bool { return resp.CommonPrefixes[i].Prefix < resp.CommonPrefixes[j].Prefix })
 	}
-	wrappedResp := struct {
-		XMLName string `xml:"http://s3.amazonaws.com/doc/2006-03-01/ ListBucketResult"`
-		s3.ListResp
-	}{"", resp}
 	w.Header().Set("Content-Type", "application/xml")
 	io.WriteString(w, xml.Header)
-	if err := xml.NewEncoder(w).Encode(wrappedResp); err != nil {
+	if err := xml.NewEncoder(w).Encode(resp); err != nil {
 		ctxlog.FromContext(r.Context()).WithError(err).Error("error writing xml response")
 	}
 }