Add notification for object access via GET/HEAD (#3941)

The following notification event types are available for all targets,
      s3:ObjectAccessed:Get
      s3:ObjectAccessed:Head
      s3:ObjectAccessed:*

cmd/bucket-notification-datatypes.go

@@ -94,6 +94,10 @@ const (
 	ObjectCreatedCompleteMultipartUpload
 	// ObjectRemovedDelete is s3:ObjectRemoved:Delete
 	ObjectRemovedDelete
+	// ObjectAccessedGet is s3:ObjectAccessed:Get
+	ObjectAccessedGet
+	// ObjectAccessedHead is s3:ObjectAccessed:Head
+	ObjectAccessedHead
 )
 
 // Stringer interface for event name.
@@ -109,6 +113,10 @@ func (eventName EventName) String() string {
 		return "s3:ObjectCreated:CompleteMultipartUpload"
 	case ObjectRemovedDelete:
 		return "s3:ObjectRemoved:Delete"
+	case ObjectAccessedGet:
+		return "s3:ObjectAccessed:Get"
+	case ObjectAccessedHead:
+		return "s3:ObjectAccessed:Head"
 	default:
 		return "s3:Unknown"
 	}

cmd/bucket-notification-handlers_test.go

@@ -268,6 +268,7 @@ func testListenBucketNotificationNilHandler(obj ObjectLayer, instanceType, bucke
 			[]string{"*.jpg"}, []string{
 				"s3:ObjectCreated:*",
 				"s3:ObjectRemoved:*",
+				"s3:ObjectAccessed:*",
 			}), 0, nil, credentials.AccessKey, credentials.SecretKey)
 	if tErr != nil {
 		t.Fatalf("%s: Failed to create HTTP testRequest for ListenBucketNotification: <ERROR> %v", instanceType, tErr)

cmd/bucket-notification-utils.go

@@ -29,6 +29,9 @@ var suppportedEventTypes = map[string]struct{}{
 	// Object removed event types.
 	"s3:ObjectRemoved:*":      {},
 	"s3:ObjectRemoved:Delete": {},
+	"s3:ObjectAccessed:Get":   {},
+	"s3:ObjectAccessed:Head":  {},
+	"s3:ObjectAccessed:*":     {},
 }
 
 // checkEvent - checks if an event is supported.

cmd/object-handlers.go

@@ -173,6 +173,14 @@ func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Req
 		// call wrter.Write(nil) to set appropriate headers.
 		writer.Write(nil)
 	}
+
+	// Notify object accessed via a GET request.
+	eventNotify(eventData{
+		Type:      ObjectAccessedGet,
+		Bucket:    bucket,
+		ObjInfo:   objInfo,
+		ReqParams: extractReqParams(r),
+	})
 }
 
 // HeadObjectHandler - HEAD Object
@@ -221,6 +229,14 @@ func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Re
 
 	// Successful response.
 	w.WriteHeader(http.StatusOK)
+
+	// Notify object accessed via a HEAD request.
+	eventNotify(eventData{
+		Type:      ObjectAccessedHead,
+		Bucket:    bucket,
+		ObjInfo:   objInfo,
+		ReqParams: extractReqParams(r),
+	})
 }
 
 // Extract metadata relevant for an CopyObject operation based on conditional