kubeadm: apply a number of _test fixes

- common_test.go: use constants.CurrentKubernetesVersion
- diff_test.go: write temporary files instead of using testdata.
this allows us to not have to bump kubernetesVersions in the
testdata files (now removed)
- policy_test.go: apply fixes to tests that were previously passing,
but a bump in constants.go breaks them. these tests now work
for any version.

cmd/kubeadm/app/cmd/upgrade/BUILD

@@ -57,7 +57,9 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//cmd/kubeadm/app/apis/kubeadm:go_default_library",
+        "//cmd/kubeadm/app/constants:go_default_library",
         "//cmd/kubeadm/app/phases/upgrade:go_default_library",
+        "//vendor/github.com/pkg/errors:go_default_library",
     ],
 )
 

cmd/kubeadm/app/cmd/upgrade/common_test.go

@@ -23,16 +23,15 @@ import (
 	"testing"
 
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
-)
-
-const (
-	validConfig = `apiVersion: kubeadm.k8s.io/v1beta2
-kind: ClusterConfiguration
-kubernetesVersion: 1.13.0
-`
+	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
 )
 
 func TestGetK8sVersionFromUserInput(t *testing.T) {
+	currentVersion := "v" + constants.CurrentKubernetesVersion.String()
+	validConfig := "apiVersion: kubeadm.k8s.io/v1beta2\n" +
+		"kind: ClusterConfiguration\n" +
+		"kubernetesVersion: " + currentVersion
+
 	var tcases = []struct {
 		name               string
 		isVersionMandatory bool
@@ -62,7 +61,7 @@ func TestGetK8sVersionFromUserInput(t *testing.T) {
 			name:               "Valid config, but no version specified",
 			isVersionMandatory: true,
 			clusterConfig:      validConfig,
-			expectedVersion:    "v1.13.0",
+			expectedVersion:    currentVersion,
 		},
 		{
 			name:               "Valid config and different version specified",
@@ -105,7 +104,7 @@ func TestGetK8sVersionFromUserInput(t *testing.T) {
 				t.Errorf("Unexpected error: %+v", err)
 			}
 			if userVersion != tt.expectedVersion {
-				t.Errorf("Expected '%s', but got '%s'", tt.expectedVersion, userVersion)
+				t.Errorf("Expected %q, but got %q", tt.expectedVersion, userVersion)
 			}
 		})
 	}

cmd/kubeadm/app/cmd/upgrade/diff_test.go

@@ -18,15 +18,48 @@ package upgrade
 
 import (
 	"io/ioutil"
+	"os"
 	"testing"
+
+	"github.com/pkg/errors"
+	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
 )
 
-const (
-	testUpgradeDiffConfig   = `testdata/diff_controlplane_config.yaml`
-	testUpgradeDiffManifest = `testdata/diff_dummy_manifest.yaml`
-)
+func createTestRunDiffFile(contents []byte) (string, error) {
+	file, err := ioutil.TempFile("", "kubeadm-upgrade-diff-config-*.yaml")
+	if err != nil {
+		return "", errors.Wrap(err, "failed to create temporary test file")
+	}
+	if _, err := file.Write([]byte(contents)); err != nil {
+		return "", errors.Wrap(err, "failed to write to temporary test file")
+	}
+	if err := file.Close(); err != nil {
+		return "", errors.Wrap(err, "failed to close temporary test file")
+	}
+	return file.Name(), nil
+}
 
 func TestRunDiff(t *testing.T) {
+	currentVersion := "v" + constants.CurrentKubernetesVersion.String()
+
+	// create a temporary file with valid ClusterConfiguration
+	testUpgradeDiffConfigContents := []byte("apiVersion: kubeadm.k8s.io/v1beta2\n" +
+		"kind: ClusterConfiguration\n" +
+		"kubernetesVersion: " + currentVersion)
+	testUpgradeDiffConfig, err := createTestRunDiffFile(testUpgradeDiffConfigContents)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove(testUpgradeDiffConfig)
+
+	// create a temporary manifest file with dummy contents
+	testUpgradeDiffManifestContents := []byte("some-contents")
+	testUpgradeDiffManifest, err := createTestRunDiffFile(testUpgradeDiffManifestContents)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove(testUpgradeDiffManifest)
+
 	flags := &diffFlags{
 		cfgPath: "",
 		out:     ioutil.Discard,

cmd/kubeadm/app/cmd/upgrade/testdata/diff_controlplane_config.yaml

@@ -1,3 +0,0 @@
-apiVersion: kubeadm.k8s.io/v1beta2
-kind: ClusterConfiguration
-kubernetesVersion: 1.13.0

cmd/kubeadm/app/cmd/upgrade/testdata/diff_dummy_manifest.yaml

@@ -1 +0,0 @@
-some-empty-file-to-diff

cmd/kubeadm/app/phases/upgrade/policy_test.go

@@ -93,13 +93,12 @@ func TestEnforceVersionPolicies(t *testing.T) {
 		{
 			name: "downgrading two minor versions in one go is not supported",
 			vg: &fakeVersionGetter{
-				clusterVersion: "v1.15.3",
-				kubeletVersion: "v1.15.3",
-				kubeadmVersion: "v1.15.0",
+				clusterVersion: constants.CurrentKubernetesVersion.WithMinor(constants.CurrentKubernetesVersion.Minor() + 2).String(),
+				kubeletVersion: constants.CurrentKubernetesVersion.WithMinor(constants.CurrentKubernetesVersion.Minor() + 2).String(),
+				kubeadmVersion: constants.CurrentKubernetesVersion.String(),
 			},
-			newK8sVersion:         constants.MinimumControlPlaneVersion.WithPatch(3).String(),
+			newK8sVersion:         constants.CurrentKubernetesVersion.String(),
 			expectedMandatoryErrs: 1, // can't downgrade two minor versions
-			expectedSkippableErrs: 1, // can't upgrade old k8s with newer kubeadm
 		},
 		{
 			name: "kubeadm version must be higher than the new kube version. However, patch version skews may be forced",
@@ -213,10 +212,10 @@ func TestEnforceVersionPolicies(t *testing.T) {
 			}
 
 			if len(actualSkewErrs.Skippable) != rt.expectedSkippableErrs {
-				t.Errorf("failed TestEnforceVersionPolicies\n\texpected skippable errors: %d\n\tgot skippable errors: %d %v", rt.expectedSkippableErrs, len(actualSkewErrs.Skippable), *rt.vg)
+				t.Errorf("failed TestEnforceVersionPolicies\n\texpected skippable errors: %d\n\tgot skippable errors: %d\n%#v\n%#v", rt.expectedSkippableErrs, len(actualSkewErrs.Skippable), *rt.vg, actualSkewErrs)
 			}
 			if len(actualSkewErrs.Mandatory) != rt.expectedMandatoryErrs {
-				t.Errorf("failed TestEnforceVersionPolicies\n\texpected mandatory errors: %d\n\tgot mandatory errors: %d %v", rt.expectedMandatoryErrs, len(actualSkewErrs.Mandatory), *rt.vg)
+				t.Errorf("failed TestEnforceVersionPolicies\n\texpected mandatory errors: %d\n\tgot mandatory errors: %d\n%#v\n%#v", rt.expectedMandatoryErrs, len(actualSkewErrs.Mandatory), *rt.vg, actualSkewErrs)
 			}
 		})
 	}