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::rapidmigrationassessment_v1::
RapidMigrationAssessmentClient(
google::cloud::rapidmigrationassessment_v1::
MakeRapidMigrationAssessmentConnection(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 2025-03-21 UTC."],[[["The page documents various versions of the Rapid Migration Assessment tool, ranging from version 2.13.0 up to the latest release candidate 2.37.0-rc."],["The latest stable version documented is 2.36.0, and the page contains multiple versions all the way back to version 2.13.0."],["The default method of authentication with Google Cloud Services is through Application Default Credentials, but you can use the `UnifiedCredentialsOption` to override this behavior."],["Overriding the default credentials can be achieved by loading a service account key file, as shown in the provided code example."],["The page references documentation on the best practices for managing service account keys and the authentication components."]]],[]]
