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."],[[["This webpage provides documentation for various versions of the `accesscontextmanager` C++ client library, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["The default authentication method for the client libraries is Application Default Credentials, but this can be overridden when necessary."],["Overriding the default authentication involves providing the `UnifiedCredentialsOption`, as demonstrated in the example, using a service account key file."],["The provided example shows how to load credentials from a service account key file, which can be useful but requires caution as there are best practices for service account key management."],["The page links to additional information on Authentication Components to learn more about the functions available to create `google::cloud::Credentials` objects."]]],[]]