Unless otherwise configured, the client libraries useApplication Default Credentialsto authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing theUnifiedCredentialsOptionThe following example shows how to explicitly load a service account key file:
[](std::string const& keyfile) {
auto is = std::ifstream(keyfile);
is.exceptions(std::ios::badbit); // Minimal error handling in examples
auto contents = std::string(std::istreambuf_iterator<char>(is.rdbuf()), {});
auto options =
google::cloud::Options{}.set<google::cloud::UnifiedCredentialsOption>(
google::cloud::MakeServiceAccountCredentials(contents));
return google::cloud::redis_cluster_v1::CloudRedisClusterClient(
google::cloud::redis_cluster_v1::MakeCloudRedisClusterConnection(
options));
}
Follow these links to find examples for other*Clientclasses:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThis document provides instructions on how to override the default authentication credentials used by client libraries to access Google Cloud Services, which typically rely on Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default credentials by utilizing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and loading a service account key file, as demonstrated in the provided code example.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate version available is 2.37.0-rc, while the base version displayed is 2.27.0.\u003c/p\u003e\n"],["\u003cp\u003eThere are several previous versions of documentation available, starting from version 2.36.0 down to 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eExamples for overriding authentication are provided for \u003ccode\u003eredis_cluster_v1::CloudRedisClusterClient\u003c/code\u003e and \u003ccode\u003eredis_v1::CloudRedisClient\u003c/code\u003e, and additional information can be found in the "Best practices for managing service account keys" guide and "Authentication Components" documentation.\u003c/p\u003e\n"]]],[],null,["Version 2.27.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/redis/latest/redis-override-authentication)\n- [2.41.0](/cpp/docs/reference/redis/2.41.0/redis-override-authentication)\n- [2.40.0](/cpp/docs/reference/redis/2.40.0/redis-override-authentication)\n- [2.39.0](/cpp/docs/reference/redis/2.39.0/redis-override-authentication)\n- [2.38.0](/cpp/docs/reference/redis/2.38.0/redis-override-authentication)\n- [2.37.0](/cpp/docs/reference/redis/2.37.0/redis-override-authentication)\n- [2.36.0](/cpp/docs/reference/redis/2.36.0/redis-override-authentication)\n- [2.35.0](/cpp/docs/reference/redis/2.35.0/redis-override-authentication)\n- [2.34.0](/cpp/docs/reference/redis/2.34.0/redis-override-authentication)\n- [2.33.0](/cpp/docs/reference/redis/2.33.0/redis-override-authentication)\n- [2.32.0](/cpp/docs/reference/redis/2.32.0/redis-override-authentication)\n- [2.31.0](/cpp/docs/reference/redis/2.31.0/redis-override-authentication)\n- [2.30.0](/cpp/docs/reference/redis/2.30.0/redis-override-authentication)\n- [2.29.0](/cpp/docs/reference/redis/2.29.0/redis-override-authentication)\n- [2.28.0](/cpp/docs/reference/redis/2.28.0/redis-override-authentication)\n- [2.27.0](/cpp/docs/reference/redis/2.27.0/redis-override-authentication)\n- [2.26.0](/cpp/docs/reference/redis/2.26.0/redis-override-authentication)\n- [2.25.1](/cpp/docs/reference/redis/2.25.1/redis-override-authentication)\n- [2.24.0](/cpp/docs/reference/redis/2.24.0/redis-override-authentication)\n- [2.23.0](/cpp/docs/reference/redis/2.23.0/redis-override-authentication)\n- [2.22.1](/cpp/docs/reference/redis/2.22.1/redis-override-authentication)\n- [2.21.0](/cpp/docs/reference/redis/2.21.0/redis-override-authentication)\n- [2.20.0](/cpp/docs/reference/redis/2.20.0/redis-override-authentication)\n- [2.19.0](/cpp/docs/reference/redis/2.19.0/redis-override-authentication)\n- [2.18.0](/cpp/docs/reference/redis/2.18.0/redis-override-authentication)\n- [2.17.0](/cpp/docs/reference/redis/2.17.0/redis-override-authentication)\n- [2.16.0](/cpp/docs/reference/redis/2.16.0/redis-override-authentication)\n- [2.15.1](/cpp/docs/reference/redis/2.15.1/redis-override-authentication)\n- [2.14.0](/cpp/docs/reference/redis/2.14.0/redis-override-authentication)\n- [2.13.0](/cpp/docs/reference/redis/2.13.0/redis-override-authentication)\n- [2.12.0](/cpp/docs/reference/redis/2.12.0/redis-override-authentication)\n- [2.11.0](/cpp/docs/reference/redis/2.11.0/redis-override-authentication) \n\nHow to Override the Authentication Credentials\n==============================================\n\nUnless otherwise configured, the client libraries use [Application Default Credentials](https://cloud.google.com/docs/authentication#adc) to authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing the [UnifiedCredentialsOption](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1UnifiedCredentialsOption.html) The following example shows how to explicitly load a service account key file: \n\n [](std::string const& keyfile) {\n auto is = std::ifstream(keyfile);\n is.exceptions(std::ios::badbit); // Minimal error handling in examples\n auto contents = std::string(std::istreambuf_iterator\u003cchar\u003e(is.rdbuf()), {});\n auto options =\n google::cloud::Options{}.set\u003cgoogle::cloud::UnifiedCredentialsOption\u003e(\n google::cloud::MakeServiceAccountCredentials(contents));\n return google::cloud::redis_cluster_v1::CloudRedisClusterClient(\n google::cloud::redis_cluster_v1::MakeCloudRedisClusterConnection(\n options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`redis_cluster_v1::CloudRedisClusterClient`](/cpp/docs/reference/redis/2.27.0/redis_cluster_v1_1_1CloudRedisClusterClient-service-account-snippet)\n- [`redis_v1::CloudRedisClient`](/cpp/docs/reference/redis/2.27.0/redis_v1_1_1CloudRedisClient-service-account-snippet)\n\nKeep in mind that we chose this as an example because it is relatively easy to understand. Consult the [Best practices for managing service account keys](https://cloud.google.com/iam/docs/best-practices-for-managing-service-account-keys) guide for more details.\n\n###### See Also\n\n[Authentication Components](https://cloud.google.com/cpp/docs/reference/common/latest/group__guac.html) - for more information on the factory functions to create [`google::cloud::Credentials`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1Credentials.html) objects."]]