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::containeranalysis_v1::ContainerAnalysisClient(
google::cloud::containeranalysis_v1::MakeContainerAnalysisConnection(
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThe page provides documentation for overriding default authentication credentials when using Google Cloud C++ client libraries.\u003c/p\u003e\n"],["\u003cp\u003eVersion 2.37.0-rc is the latest available version, and the page lists various older versions from 2.36.0 down to 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eThe example code shows how to use \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e to explicitly load authentication from a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThis document contains how-to information for both the \u003ccode\u003econtaineranalysis_v1::ContainerAnalysisClient\u003c/code\u003e and \u003ccode\u003econtaineranalysis_v1::GrafeasClient\u003c/code\u003e classes.\u003c/p\u003e\n"],["\u003cp\u003eThe page also directs users to the "Best practices for managing service account keys" and "Authentication Components" guides for further information.\u003c/p\u003e\n"]]],[],null,[]]
