Replace os.Setenv with testing.T.Setenv in tests

T.Setenv ensures that the environment is returned to its prior state
when the test ends. It also panics when called from a parallel test to
prevent racy test interdependencies.

Kubernetes-commit: 2181eea48435310d1b6e366ea8db2968c4941b93

pkg/cmd/cmd_test.go

@@ -342,7 +342,7 @@ func TestKubectlCommandHeadersHooks(t *testing.T) {
 			if kubeConfigFlags.WrapConfigFn != nil {
 				t.Fatal("expected initial nil WrapConfigFn")
 			}
-			os.Setenv(kubectlCmdHeaders, testCase.envVar)
+			t.Setenv(kubectlCmdHeaders, testCase.envVar)
 			addCmdHeaderHooks(cmds, kubeConfigFlags)
 			// Valdidate whether the hooks were added.
 			if testCase.addsHooks && kubeConfigFlags.WrapConfigFn == nil {

pkg/cmd/create/create_configmap_test.go

@@ -293,8 +293,8 @@ func TestCreateConfigMap(t *testing.T) {
 		"create_get_env_from_env_file_configmap": {
 			configMapName: "get_env",
 			setup: func() func(t *testing.T, configMapOptions *ConfigMapOptions) func() {
-				os.Setenv("g_key1", "1")
-				os.Setenv("g_key2", "2")
+				t.Setenv("g_key1", "1")
+				t.Setenv("g_key2", "2")
 				return setupEnvFile([][]string{{"g_key1", "g_key2="}})
 			}(),
 			fromEnvFile: []string{"file.env"},
@@ -316,8 +316,8 @@ func TestCreateConfigMap(t *testing.T) {
 		"create_get_env_from_env_file_hash_configmap": {
 			configMapName: "get_env",
 			setup: func() func(t *testing.T, configMapOptions *ConfigMapOptions) func() {
-				os.Setenv("g_key1", "1")
-				os.Setenv("g_key2", "2")
+				t.Setenv("g_key1", "1")
+				t.Setenv("g_key2", "2")
 				return setupEnvFile([][]string{{"g_key1", "g_key2="}})
 			}(),
 			fromEnvFile: []string{"file.env"},

pkg/cmd/create/create_secret_test.go

@@ -340,8 +340,8 @@ func TestCreateSecretGeneric(t *testing.T) {
 		"create_secret_get_env_from_env_file": {
 			secretName: "get_env",
 			setup: func() func(t *testing.T, secretGenericOptions *CreateSecretOptions) func() {
-				os.Setenv("g_key1", "1")
-				os.Setenv("g_key2", "2")
+				t.Setenv("g_key1", "1")
+				t.Setenv("g_key2", "2")
 				return setupSecretEnvFile([][]string{{"g_key1", "g_key2="}})
 			}(),
 			fromEnvFile: []string{"file.env"},
@@ -362,8 +362,8 @@ func TestCreateSecretGeneric(t *testing.T) {
 		"create_secret_get_env_from_env_file_hash": {
 			secretName: "get_env",
 			setup: func() func(t *testing.T, secretGenericOptions *CreateSecretOptions) func() {
-				os.Setenv("g_key1", "1")
-				os.Setenv("g_key2", "2")
+				t.Setenv("g_key1", "1")
+				t.Setenv("g_key2", "2")
 				return setupSecretEnvFile([][]string{{"g_key1", "g_key2="}})
 			}(),
 			fromEnvFile: []string{"file.env"},

pkg/cmd/diff/diff_test.go

@@ -64,13 +64,10 @@ func (f *FakeObject) Live() runtime.Object {
 func TestDiffProgram(t *testing.T) {
 	externalDiffCommands := [3]string{"diff", "diff -ruN", "diff --report-identical-files"}
 
-	if oriLang := os.Getenv("LANG"); oriLang != "C" {
-		os.Setenv("LANG", "C")
-		defer os.Setenv("LANG", oriLang)
-	}
+	t.Setenv("LANG", "C")
 
 	for i, c := range externalDiffCommands {
-		os.Setenv("KUBECTL_EXTERNAL_DIFF", c)
+		t.Setenv("KUBECTL_EXTERNAL_DIFF", c)
 		streams, _, stdout, _ := genericiooptions.NewTestIOStreams()
 		diff := DiffProgram{
 			IOStreams: streams,

pkg/cmd/edit/edit_test.go

@@ -170,8 +170,8 @@ func TestEdit(t *testing.T) {
 	server := httptest.NewServer(handler)
 	defer server.Close()
 
-	os.Setenv("KUBE_EDITOR", "testdata/test_editor.sh")
-	os.Setenv("KUBE_EDITOR_CALLBACK", server.URL+"/callback")
+	t.Setenv("KUBE_EDITOR", "testdata/test_editor.sh")
+	t.Setenv("KUBE_EDITOR_CALLBACK", server.URL+"/callback")
 
 	testcases := sets.NewString()
 	filepath.Walk("testdata", func(path string, info os.FileInfo, err error) error {

pkg/cmd/util/env_file_test.go

@@ -17,7 +17,6 @@ limitations under the License.
 package util
 
 import (
-	"os"
 	"strings"
 	"testing"
 )
@@ -85,12 +84,7 @@ func Test_processEnvFileLine_readEnvironment(t *testing.T) {
 	const realKey = "k8s_test_env_file_key"
 	const realValue = `my_value`
 
-	// Just in case, these two lines ensure the environment is restored to
-	// its original state.
-	original := os.Getenv(realKey)
-	defer func() { os.Setenv(realKey, original) }()
-
-	os.Setenv(realKey, `my_value`)
+	t.Setenv(realKey, `my_value`)
 
 	key, value, err := processEnvFileLine([]byte(realKey), `filename`, 3)
 	if err != nil {