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::alloydb_v1::AlloyDBAdminClient(
google::cloud::alloydb_v1::MakeAlloyDBAdminConnection(options));
}
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThe webpage provides documentation for overriding default authentication credentials when interacting with Google Cloud Services, specifically within the context of C++ client libraries.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release candidate version for the documentation available is 2.37.0-rc, and it also includes documentation for 27 past versions, ranging from 2.11.0 to 2.36.0.\u003c/p\u003e\n"],["\u003cp\u003eOverriding the default Application Default Credentials can be achieved by utilizing the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, which allows you to load credentials, such as those from a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe provided example demonstrates loading a service account key file and using it to create an \u003ccode\u003eAlloyDBAdminClient\u003c/code\u003e with the specified credentials, however there is a guide for best practices for managing service account keys for more details.\u003c/p\u003e\n"],["\u003cp\u003eFor additional information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, you can refer to the "Authentication Components" documentation.\u003c/p\u003e\n"]]],[],null,[]]
