kubeadm: sort the results of MergeKubeadmEnvVars

MergeKubeadmEnvVars use a map which results in non
deterministic output in the end slice EnvVar objects.
Before returning the slice, sort it by the Name field.

Update the unit test to capture the sorting aspect.

cmd/kubeadm/app/util/env.go

@@ -18,6 +18,7 @@ package util
 
 import (
 	"os"
+	"sort"
 	"strings"
 
 	v1 "k8s.io/api/core/v1"
@@ -63,5 +64,8 @@ func MergeKubeadmEnvVars(envList ...[]kubeadmapi.EnvVar) []v1.EnvVar {
 	for _, v := range m {
 		merged = append(merged, v)
 	}
+	sort.Slice(merged, func(i, j int) bool {
+		return merged[i].Name < merged[j].Name
+	})
 	return merged
 }

cmd/kubeadm/app/util/env_test.go

@@ -20,8 +20,6 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/stretchr/testify/assert"
-
 	v1 "k8s.io/api/core/v1"
 
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
@@ -41,10 +39,10 @@ func TestMergeKubeadmEnvVars(t *testing.T) {
 			name: "normal case without duplicated env",
 			proxyEnv: []kubeadmapi.EnvVar{
 				{
-					EnvVar: v1.EnvVar{Name: "Foo1", Value: "Bar1"},
+					EnvVar: v1.EnvVar{Name: "Foo2", Value: "Bar2"},
 				},
 				{
-					EnvVar: v1.EnvVar{Name: "Foo2", Value: "Bar2"},
+					EnvVar: v1.EnvVar{Name: "Foo1", Value: "Bar1"},
 				},
 			},
 			extraEnv: []kubeadmapi.EnvVar{
@@ -83,7 +81,7 @@ func TestMergeKubeadmEnvVars(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			envs := MergeKubeadmEnvVars(test.proxyEnv, test.extraEnv)
-			if !assert.ElementsMatch(t, envs, test.mergedEnv) {
+			if !reflect.DeepEqual(envs, test.mergedEnv) {
 				t.Errorf("expected env: %v, got: %v", test.mergedEnv, envs)
 			}
 		})