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::accesscontextmanager_v1::AccessContextManagerClient(
google::cloud::accesscontextmanager_v1::
MakeAccessContextManagerConnection(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 2025-03-05 UTC."],[[["The latest version of the documentation is 2.37.0-rc, with a comprehensive list of previous versions available, ranging from 2.36.0 down to 2.11.0."],["By default, client libraries use Application Default Credentials for authentication, but this can be overridden using UnifiedCredentialsOption."],["You can override the default credentials by loading a service account key file, as demonstrated in the provided example code, using the `MakeServiceAccountCredentials` method."],["For detailed guidance on handling service account keys, refer to the \"Best practices for managing service account keys\" guide, and for creating `google::cloud::Credentials` objects, see the \"Authentication Components\" documentation."]]],[]]
