Fix pkg/v1/google/auth tests for arm64

pkg/v1/google/auth.go

@@ -30,16 +30,19 @@ import (
 
 const cloudPlatformScope = "https://www.googleapis.com/auth/cloud-platform"
 
-// GetGcloudCmd is exposed so we can test this.
-var GetGcloudCmd = func(ctx context.Context) *exec.Cmd {
+// gcloudBin is replaced in tests to mock detecting the gcloud binary.
+var gcloudBin = "gcloud"
+
+// getGcloudCmd is replaced in tests to drive the gcloud mock.
+var getGcloudCmd = func(ctx context.Context) *exec.Cmd {
 	// This is odd, but basically what docker-credential-gcr does.
 	//
 	// config-helper is undocumented, but it's purportedly the only supported way
 	// of accessing tokens (`gcloud auth print-access-token` is discouraged).
 	//
 	// --force-auth-refresh means we are getting a token that is valid for about
 	// an hour (we reuse it until it's expired).
-	return exec.CommandContext(ctx, "gcloud", "config", "config-helper", "--force-auth-refresh", "--format=json(credential)")
+	return exec.CommandContext(ctx, gcloudBin, "config", "config-helper", "--force-auth-refresh", "--format=json(credential)")
 }
 
 // NewEnvAuthenticator returns an authn.Authenticator that generates access
@@ -63,13 +66,13 @@ func NewEnvAuthenticator(ctx context.Context) (authn.Authenticator, error) {
 // NewGcloudAuthenticator returns an oauth2.TokenSource that generates access
 // tokens by shelling out to the gcloud sdk.
 func NewGcloudAuthenticator(ctx context.Context) (authn.Authenticator, error) {
-	if _, err := exec.LookPath("gcloud"); err != nil {
+	if _, err := exec.LookPath(gcloudBin); err != nil {
 		// gcloud is not available, fall back to anonymous
 		logs.Warn.Println("gcloud binary not found")
 		return authn.Anonymous, nil
 	}
 
-	ts := gcloudSource{ctx, GetGcloudCmd}
+	ts := gcloudSource{ctx, getGcloudCmd}
 
 	// Attempt to fetch a token to ensure gcloud is installed and we can run it.
 	token, err := ts.Token()

pkg/v1/google/auth_test.go

@@ -1,6 +1,3 @@
-//go:build !arm64
-// +build !arm64
-
 // Copyright 2018 Google LLC All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -59,9 +56,8 @@ const (
 // out the gcloud dependency of gcloudSource. The exec package does this, too.
 //
 // See: https://www.joeshaw.org/testing-with-os-exec-and-testmain/
-//
-// TODO(#908): This doesn't work on arm64 or darwin for some reason.
 func TestMain(m *testing.M) {
+	gcloudBin = os.Args[0]
 	switch os.Getenv("GO_TEST_MODE") {
 	case "":
 		// Normal test mode
@@ -113,7 +109,7 @@ func TestGcloudErrors(t *testing.T) {
 
 	for _, tc := range cases {
 		t.Run(tc.env, func(t *testing.T) {
-			GetGcloudCmd = newGcloudCmdMock(tc.env)
+			getGcloudCmd = newGcloudCmdMock(tc.env)
 
 			if _, err := NewGcloudAuthenticator(ctx); err == nil {
 				t.Errorf("wanted error, got nil")
@@ -130,7 +126,7 @@ func TestGcloudSuccess(t *testing.T) {
 	var b bytes.Buffer
 	logs.Debug.SetOutput(&b)
 
-	GetGcloudCmd = newGcloudCmdMock("success")
+	getGcloudCmd = newGcloudCmdMock("success")
 
 	auth, err := NewGcloudAuthenticator(ctx)
 	if err != nil {
@@ -204,7 +200,7 @@ func TestKeychainGCRandAR(t *testing.T) {
 			Keychain = &googleKeychain{}
 
 			// Gcloud should succeed.
-			GetGcloudCmd = newGcloudCmdMock("success")
+			getGcloudCmd = newGcloudCmdMock("success")
 
 			if auth, err := Keychain.Resolve(mustRegistry(tc.host)); err != nil {
 				t.Errorf("expected success for %v, got: %v", tc.host, err)
@@ -215,7 +211,7 @@ func TestKeychainGCRandAR(t *testing.T) {
 			}
 
 			// Make gcloud fail to test that caching works.
-			GetGcloudCmd = newGcloudCmdMock("badoutput")
+			getGcloudCmd = newGcloudCmdMock("badoutput")
 
 			if auth, err := Keychain.Resolve(mustRegistry(tc.host)); err != nil {
 				t.Errorf("expected success for %v, got: %v", tc.host, err)
@@ -233,7 +229,7 @@ func TestKeychainError(t *testing.T) {
 		t.Fatalf("unexpected err os.Setenv: %v", err)
 	}
 
-	GetGcloudCmd = newGcloudCmdMock("badoutput")
+	getGcloudCmd = newGcloudCmdMock("badoutput")
 
 	// Reset the keychain to ensure we don't cache earlier results.
 	Keychain = &googleKeychain{}