CredentialsTest: Fix TestGoogleDefaultCredsExternalAccountCredentials (#28923)

test/core/security/credentials_test.cc

@@ -114,9 +114,11 @@ static const char test_refresh_token_str[] =
 static const char test_external_account_credentials_str[] =
     "{\"type\":\"external_account\",\"audience\":\"audience\",\"subject_"
     "token_type\":\"subject_token_type\",\"service_account_impersonation_"
-    "url\":\"\",\"token_url\":\"https://"
+    "url\":\"https://iamcredentials.googleapis.com:5555/"
+    "service_account_impersonation_url\",\"token_url\":\"https://"
     "sts.googleapis.com:5555/"
-    "token\",\"token_info_url\":\"\",\"credential_source\":{\"file\":"
+    "token\",\"token_info_url\":\"https://sts.googleapis.com:5555/"
+    "token_info\",\"credential_source\":{\"file\":"
     "\"credentials_file_path\"},"
     "\"quota_project_id\":\"quota_"
     "project_id\",\"client_id\":\"client_id\",\"client_secret\":\"client_"
@@ -1485,6 +1487,8 @@ static bool test_gce_tenancy_checker(void) {
   return g_test_is_on_gce;
 }
 
+static std::string null_well_known_creds_path_getter(void) { return ""; }
+
 TEST(CredentialsTest, TestGoogleDefaultCredsAuthKey) {
   grpc_core::ExecCtx exec_ctx;
   grpc_composite_channel_credentials* creds;
@@ -1495,6 +1499,8 @@ TEST(CredentialsTest, TestGoogleDefaultCredsAuthKey) {
   g_test_is_on_gce = true;
   set_google_default_creds_env_var_with_file_contents(
       "json_key_google_default_creds", json_key);
+  grpc_override_well_known_credentials_path_getter(
+      null_well_known_creds_path_getter);
   gpr_free(json_key);
   creds = reinterpret_cast<grpc_composite_channel_credentials*>(
       grpc_google_default_credentials_create(nullptr));
@@ -1512,6 +1518,7 @@ TEST(CredentialsTest, TestGoogleDefaultCredsAuthKey) {
   GPR_ASSERT(g_test_gce_tenancy_checker_called == false);
   creds->Unref();
   gpr_setenv(GRPC_GOOGLE_CREDENTIALS_ENV_VAR, ""); /* Reset. */
+  grpc_override_well_known_credentials_path_getter(nullptr);
 }
 
 TEST(CredentialsTest, TestGoogleDefaultCredsRefreshToken) {
@@ -1520,6 +1527,8 @@ TEST(CredentialsTest, TestGoogleDefaultCredsRefreshToken) {
   grpc_flush_cached_google_default_credentials();
   set_google_default_creds_env_var_with_file_contents(
       "refresh_token_google_default_creds", test_refresh_token_str);
+  grpc_override_well_known_credentials_path_getter(
+      null_well_known_creds_path_getter);
   creds = reinterpret_cast<grpc_composite_channel_credentials*>(
       grpc_google_default_credentials_create(nullptr));
   auto* default_creds =
@@ -1533,6 +1542,7 @@ TEST(CredentialsTest, TestGoogleDefaultCredsRefreshToken) {
                     "32555999999.apps.googleusercontent.com") == 0);
   creds->Unref();
   gpr_setenv(GRPC_GOOGLE_CREDENTIALS_ENV_VAR, ""); /* Reset. */
+  grpc_override_well_known_credentials_path_getter(nullptr);
 }
 
 TEST(CredentialsTest, TestGoogleDefaultCredsExternalAccountCredentials) {
@@ -1542,6 +1552,8 @@ TEST(CredentialsTest, TestGoogleDefaultCredsExternalAccountCredentials) {
   set_google_default_creds_env_var_with_file_contents(
       "google_default_creds_external_account_credentials",
       test_external_account_credentials_str);
+  grpc_override_well_known_credentials_path_getter(
+      null_well_known_creds_path_getter);
   creds = reinterpret_cast<grpc_composite_channel_credentials*>(
       grpc_google_default_credentials_create(nullptr));
   auto* default_creds =
@@ -1554,6 +1566,7 @@ TEST(CredentialsTest, TestGoogleDefaultCredsExternalAccountCredentials) {
   GPR_ASSERT(external != nullptr);
   creds->Unref();
   gpr_setenv(GRPC_GOOGLE_CREDENTIALS_ENV_VAR, ""); /* Reset. */
+  grpc_override_well_known_credentials_path_getter(nullptr);
 }
 
 TEST(CredentialsTest,
@@ -1562,8 +1575,10 @@ TEST(CredentialsTest,
   grpc_composite_channel_credentials* creds;
   grpc_flush_cached_google_default_credentials();
   set_google_default_creds_env_var_with_file_contents(
-      "google_default_creds_external_account_credentials",
+      "google_default_creds_external_account_credentials_multi_pattern_sts",
       test_external_account_credentials_multi_pattern_sts_str);
+  grpc_override_well_known_credentials_path_getter(
+      null_well_known_creds_path_getter);
   creds = reinterpret_cast<grpc_composite_channel_credentials*>(
       grpc_google_default_credentials_create(nullptr));
   auto* default_creds =
@@ -1576,6 +1591,7 @@ TEST(CredentialsTest,
   GPR_ASSERT(external != nullptr);
   creds->Unref();
   gpr_setenv(GRPC_GOOGLE_CREDENTIALS_ENV_VAR, ""); /* Reset. */
+  grpc_override_well_known_credentials_path_getter(nullptr);
 }
 
 TEST(CredentialsTest,
@@ -1584,8 +1600,10 @@ TEST(CredentialsTest,
   grpc_composite_channel_credentials* creds;
   grpc_flush_cached_google_default_credentials();
   set_google_default_creds_env_var_with_file_contents(
-      "google_default_creds_external_account_credentials",
+      "google_default_creds_external_account_credentials_multi_pattern_iam",
       test_external_account_credentials_multi_pattern_iam_str);
+  grpc_override_well_known_credentials_path_getter(
+      null_well_known_creds_path_getter);
   creds = reinterpret_cast<grpc_composite_channel_credentials*>(
       grpc_google_default_credentials_create(nullptr));
   auto* default_creds =
@@ -1598,6 +1616,7 @@ TEST(CredentialsTest,
   GPR_ASSERT(external != nullptr);
   creds->Unref();
   gpr_setenv(GRPC_GOOGLE_CREDENTIALS_ENV_VAR, ""); /* Reset. */
+  grpc_override_well_known_credentials_path_getter(nullptr);
 }
 
 static int default_creds_metadata_server_detection_httpcli_get_success_override(
@@ -1617,8 +1636,6 @@ static int default_creds_metadata_server_detection_httpcli_get_success_override(
   return 1;
 }
 
-static std::string null_well_known_creds_path_getter(void) { return ""; }
-
 TEST(CredentialsTest, TestGoogleDefaultCredsGce) {
   grpc_core::ExecCtx exec_ctx;
   std::map<std::string, std::string> emd = {