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::container_v1::ClusterManagerClient(
google::cloud::container_v1::MakeClusterManagerConnection(options));
}
[[["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 2025-03-14 UTC."],[[["This page lists various versions of the C++ client library, ranging from version 2.11.0 to the latest release candidate, 2.37.0-rc."],["The primary topic discussed is how to override default authentication credentials when using the C++ client libraries with Google Cloud Services."],["Overriding the default is done by providing the `UnifiedCredentialsOption` and is shown by providing an example of how to explicitly load a service account key file."],["The document refers to using Application Default Credentials as the standard approach to authenticate with Google Cloud Services, unless otherwise configured."],["The page directs users to consult the \"Best practices for managing service account keys\" guide for additional information and the Authentication Components for more information on factory functions to create `google::cloud::Credentials`."]]],[]]