tools/functional-tester: add isolate failures

pkg/netutil/isolate_linux.go

@@ -0,0 +1,42 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package netutil
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+// DropPort drops all network packets that are received from the given port and sent to the given port.
+func DropPort(port int) error {
+	cmdStr := fmt.Sprintf("sudo iptables -A OUTPUT --destination-port %d -j DROP", port)
+	if _, err := exec.Command("/bin/sh", "-c", cmdStr).Output(); err != nil {
+		return err
+	}
+	cmdStr = fmt.Sprintf("sudo iptables -A INPUT --destination-port %d -j DROP", port)
+	_, err := exec.Command("/bin/sh", "-c", cmdStr).Output()
+	return err
+}
+
+// RecoverPort stops dropping network packets at given port.
+func RecoverPort(port int) error {
+	cmdStr := fmt.Sprintf("sudo iptables -D OUTPUT --destination-port %d -j DROP", port)
+	if _, err := exec.Command("/bin/sh", "-c", cmdStr).Output(); err != nil {
+		return err
+	}
+	cmdStr = fmt.Sprintf("sudo iptables -D INPUT --destination-port %d -j DROP", port)
+	_, err := exec.Command("/bin/sh", "-c", cmdStr).Output()
+	return err
+}