From 89b67db4472401f309ed2989c934bfaf64d139ad Mon Sep 17 00:00:00 2001
From: Fabio Falci <fabiofalci@gmail.com>
Date: Thu, 26 Jun 2014 12:03:23 +0100
Subject: [PATCH] Relax dns search to accept empty domain

In that case /etc/resolv.conf will be generated with no search
option. Usage: --dns-search=.

Docker-DCO-1.1-Signed-off-by: Fabio Falci <fabiofalci@gmail.com> (github: fabiofalci)
Upstream-commit: 9fdc86ac55646015a8421645e1cab7b51bc58380
Component: cli
---
 components/cli/opts/opts.go      | 11 ++++++++++-
 components/cli/opts/opts_test.go | 14 ++++++++------
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/components/cli/opts/opts.go b/components/cli/opts/opts.go
index 67f1c8fd48..d17b57e07c 100644
--- a/components/cli/opts/opts.go
+++ b/components/cli/opts/opts.go
@@ -137,7 +137,16 @@ func ValidateIp4Address(val string) (string, error) {
 	return "", fmt.Errorf("%s is not an ip4 address", val)
 }
 
-func ValidateDomain(val string) (string, error) {
+// Validates domain for resolvconf search configuration.
+// A zero length domain is represented by .
+func ValidateDnsSearch(val string) (string, error) {
+	if val = strings.Trim(val, " "); val == "." {
+		return val, nil
+	}
+	return validateDomain(val)
+}
+
+func validateDomain(val string) (string, error) {
 	alpha := regexp.MustCompile(`[a-zA-Z]`)
 	if alpha.FindString(val) == "" {
 		return "", fmt.Errorf("%s is not a valid domain", val)
diff --git a/components/cli/opts/opts_test.go b/components/cli/opts/opts_test.go
index 299cbfe503..b18088b934 100644
--- a/components/cli/opts/opts_test.go
+++ b/components/cli/opts/opts_test.go
@@ -23,8 +23,9 @@ func TestValidateIP4(t *testing.T) {
 
 }
 
-func TestValidateDomain(t *testing.T) {
+func TestValidateDnsSearch(t *testing.T) {
 	valid := []string{
+		`.`,
 		`a`,
 		`a.`,
 		`1.foo`,
@@ -49,7 +50,8 @@ func TestValidateDomain(t *testing.T) {
 
 	invalid := []string{
 		``,
-		`.`,
+		` `,
+		`  `,
 		`17`,
 		`17.`,
 		`.17`,
@@ -65,14 +67,14 @@ func TestValidateDomain(t *testing.T) {
 	}
 
 	for _, domain := range valid {
-		if ret, err := ValidateDomain(domain); err != nil || ret == "" {
-			t.Fatalf("ValidateDomain(`"+domain+"`) got %s %s", ret, err)
+		if ret, err := ValidateDnsSearch(domain); err != nil || ret == "" {
+			t.Fatalf("ValidateDnsSearch(`"+domain+"`) got %s %s", ret, err)
 		}
 	}
 
 	for _, domain := range invalid {
-		if ret, err := ValidateDomain(domain); err == nil || ret != "" {
-			t.Fatalf("ValidateDomain(`"+domain+"`) got %s %s", ret, err)
+		if ret, err := ValidateDnsSearch(domain); err == nil || ret != "" {
+			t.Fatalf("ValidateDnsSearch(`"+domain+"`) got %s %s", ret, err)
 		}
 	}
 }