Unless otherwise configured, the client libraries use Application Default Credentials 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 The 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 *Client classes:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis document provides guidance on overriding default authentication credentials when using Google Cloud client libraries for C++.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate version is 2.37.0-rc, but the current version used in this page example is 2.32.0.\u003c/p\u003e\n"],["\u003cp\u003eOverriding authentication can be achieved by utilizing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e and explicitly loading a service account key file, as demonstrated in the provided code snippet.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries default to using Application Default Credentials for authentication unless a different method is configured.\u003c/p\u003e\n"],["\u003cp\u003eExamples of how to override credentials for \u003ccode\u003eredis_cluster_v1::CloudRedisClusterClient\u003c/code\u003e and \u003ccode\u003eredis_v1::CloudRedisClient\u003c/code\u003e classes are also provided, and users are encouraged to consult best practices for service account key management.\u003c/p\u003e\n"]]],[],null,[]]
