From 2d7bfa2f2c9c72dc6d8171b4a22618aeebcf91df Mon Sep 17 00:00:00 2001
From: Mingzhen Feng <fmzhen@zju.edu.cn>
Date: Thu, 16 Apr 2015 15:09:36 +0800
Subject: [PATCH] Removal of the regex to replace ips

Signed-off-by: Mingzhen Feng <fmzhen@zju.edu.cn>
Upstream-commit: 3ab7ceb5d7aaa5fc04af98aae4115201ebae13ee
Component: engine
---
 .../integration-cli/docker_cli_daemon_test.go | 35 +++++++++++++++++++
 components/engine/pkg/iptables/iptables.go    | 10 +-----
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/components/engine/integration-cli/docker_cli_daemon_test.go b/components/engine/integration-cli/docker_cli_daemon_test.go
index b2eb46bd07..030c670ae3 100644
--- a/components/engine/integration-cli/docker_cli_daemon_test.go
+++ b/components/engine/integration-cli/docker_cli_daemon_test.go
@@ -564,6 +564,41 @@ func (s *DockerDaemonSuite) TestDaemonBridgeIP(c *check.C) {
 	deleteInterface(c, defaultNetworkBridge)
 }
 
+func (s *DockerDaemonSuite) TestDaemonRestartWithBridgeIPChange(c *check.C) {
+	if err := s.d.Start(); err != nil {
+		c.Fatalf("Could not start daemon: %v", err)
+	}
+	defer s.d.Restart()
+	if err := s.d.Stop(); err != nil {
+		c.Fatalf("Could not stop daemon: %v", err)
+	}
+
+	// now we will change the docker0's IP and then try starting the daemon
+	bridgeIP := "192.169.100.1/24"
+	_, bridgeIPNet, _ := net.ParseCIDR(bridgeIP)
+
+	ipCmd := exec.Command("ifconfig", "docker0", bridgeIP)
+	stdout, stderr, _, err := runCommandWithStdoutStderr(ipCmd)
+	if err != nil {
+		c.Fatalf("failed to change docker0's IP association: %v, stdout: %q, stderr: %q", err, stdout, stderr)
+	}
+
+	if err := s.d.Start("--bip", bridgeIP); err != nil {
+		c.Fatalf("Could not start daemon: %v", err)
+	}
+
+	//check if the iptables contains new bridgeIP MASQUERADE rule
+	ipTablesSearchString := bridgeIPNet.String()
+	ipTablesCmd := exec.Command("iptables", "-t", "nat", "-nvL")
+	out, _, err := runCommandWithOutput(ipTablesCmd)
+	if err != nil {
+		c.Fatalf("Could not run iptables -nvL: %s, %v", out, err)
+	}
+	if !strings.Contains(out, ipTablesSearchString) {
+		c.Fatalf("iptables output should have contained new MASQUERADE rule with IP %q, but was %q", ipTablesSearchString, out)
+	}
+}
+
 func (s *DockerDaemonSuite) TestDaemonBridgeFixedCidr(c *check.C) {
 	d := s.d
 
diff --git a/components/engine/pkg/iptables/iptables.go b/components/engine/pkg/iptables/iptables.go
index f772a33ca7..9cf1bbfa5c 100644
--- a/components/engine/pkg/iptables/iptables.go
+++ b/components/engine/pkg/iptables/iptables.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"net"
 	"os/exec"
-	"regexp"
 	"strconv"
 	"strings"
 	"sync"
@@ -267,14 +266,7 @@ func Exists(table Table, chain string, rule ...string) bool {
 	ruleString := strings.Join(rule, " ")
 	existingRules, _ := exec.Command(iptablesPath, "-t", string(table), "-S", chain).Output()
 
-	// regex to replace ips in rule
-	// because MASQUERADE rule will not be exactly what was passed
-	re := regexp.MustCompile(`[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\/[0-9]{1,2}`)
-
-	return strings.Contains(
-		re.ReplaceAllString(string(existingRules), "?"),
-		re.ReplaceAllString(ruleString, "?"),
-	)
+	return strings.Contains(string(existingRules), ruleString)
 }
 
 // Call 'iptables' system command, passing supplied arguments