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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 information on how to override the default authentication credentials used by client libraries to connect to Google Cloud Services.\u003c/p\u003e\n"],["\u003cp\u003eThe default authentication method is the Application Default Credentials, but the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e allows overriding these defaults.\u003c/p\u003e\n"],["\u003cp\u003eAn example is provided for loading a service account key file to authenticate, which uses \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe document references other client classes, specifically \u003ccode\u003eredis_cluster_v1::CloudRedisClusterClient\u003c/code\u003e and \u003ccode\u003eredis_v1::CloudRedisClient\u003c/code\u003e, with links to further examples.\u003c/p\u003e\n"],["\u003cp\u003eA link to the "Best practices for managing service account keys" guide is provided for more detailed information, as well as a link to "Authentication Components".\u003c/p\u003e\n"]]],[],null,[]]
