From d8fcf4fcd7c607f8f36c598d480214235cf80d9e Mon Sep 17 00:00:00 2001
From: Alexander Kanevskiy <alexander.kanevskiy@intel.com>
Date: Wed, 5 Jul 2017 19:41:57 +0300
Subject: [PATCH] Allows to use versions like 1.6.4 instead v1.6.4

As part of issue kubernetes/kubeadm#292 discussion, it
turned out that for users it is not always obvious that
version specification parameter must be in form "vX.Y.Z".
This patch allows to specify it in form "X.Y.Z" and
converts it internally to normal semantic version which
expected in the rest of the code.
---
 cmd/kubeadm/app/util/version.go      |  7 +++++--
 cmd/kubeadm/app/util/version_test.go | 24 ++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/cmd/kubeadm/app/util/version.go b/cmd/kubeadm/app/util/version.go
index 8f2bf7d44e..240575dd56 100644
--- a/cmd/kubeadm/app/util/version.go
+++ b/cmd/kubeadm/app/util/version.go
@@ -26,7 +26,7 @@ import (
 
 var (
 	kubeReleaseBucketURL  = "https://storage.googleapis.com/kubernetes-release/release"
-	kubeReleaseRegex      = regexp.MustCompile(`^v(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)([-0-9a-zA-Z_\.+]*)?$`)
+	kubeReleaseRegex      = regexp.MustCompile(`^v?(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)([-0-9a-zA-Z_\.+]*)?$`)
 	kubeReleaseLabelRegex = regexp.MustCompile(`^[[:lower:]]+(-[-\w_\.]+)?$`)
 )
 
@@ -49,7 +49,10 @@ var (
 //  latest-1.0  (and similarly 1.1, 1.2, 1.3, ...)
 func KubernetesReleaseVersion(version string) (string, error) {
 	if kubeReleaseRegex.MatchString(version) {
-		return version, nil
+		if strings.HasPrefix(version, "v") {
+			return version, nil
+		}
+		return "v" + version, nil
 	} else if kubeReleaseLabelRegex.MatchString(version) {
 		url := fmt.Sprintf("%s/%s.txt", kubeReleaseBucketURL, version)
 		resp, err := http.Get(url)
diff --git a/cmd/kubeadm/app/util/version_test.go b/cmd/kubeadm/app/util/version_test.go
index 418f7b0dc1..5f3325af0d 100644
--- a/cmd/kubeadm/app/util/version_test.go
+++ b/cmd/kubeadm/app/util/version_test.go
@@ -45,6 +45,7 @@ func TestValidVersion(t *testing.T) {
 		"v1.6.0-alpha.0.536+d60d9f3269288f",
 		"v1.5.0-alpha.0.1078+1044b6822497da-pull",
 		"v1.5.0-alpha.1.822+49b9e32fad9f32-pull-gke-gci",
+		"v1.6.1_coreos.0",
 	}
 	for _, s := range validVersions {
 		ver, err := KubernetesReleaseVersion(s)
@@ -61,8 +62,9 @@ func TestValidVersion(t *testing.T) {
 func TestInvalidVersion(t *testing.T) {
 	invalidVersions := []string{
 		"v1.3",
-		"1.4.0",
-		"1.4.5+git",
+		"1.4",
+		"b1.4.0",
+		"c1.4.5+git",
 		"something1.2",
 	}
 	for _, s := range invalidVersions {
@@ -77,6 +79,24 @@ func TestInvalidVersion(t *testing.T) {
 	}
 }
 
+func TestValidConvenientForUserVersion(t *testing.T) {
+	validVersions := []string{
+		"1.4.0",
+		"1.4.5+git",
+		"1.6.1_coreos.0",
+	}
+	for _, s := range validVersions {
+		ver, err := KubernetesReleaseVersion(s)
+		t.Log("Valid: ", s, ver, err)
+		if err != nil {
+			t.Errorf("KubernetesReleaseVersion unexpected error for version %q: %v", s, err)
+		}
+		if ver != "v"+s {
+			t.Errorf("KubernetesReleaseVersion should return semantic version string. %q vs. %q", s, ver)
+		}
+	}
+}
+
 func TestVersionFromNetwork(t *testing.T) {
 	type T struct {
 		Content       string