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 2025-03-14 UTC."],[[["This page provides documentation for various versions of the Rapid Migration Assessment tool, ranging from version 2.13.0 to the latest release candidate 2.37.0-rc."],["The default authentication method for client libraries is Application Default Credentials, but they can be overridden when needed."],["Authentication can be overridden by utilizing the `UnifiedCredentialsOption`, such as loading a service account key file."],["A sample example demonstrates loading a service account key file for overriding authentication, which is a simple yet effective way to understand how to implement this."],["For detailed information on creating credentials objects and best practices for managing service account keys, consult the provided documentation links."]]],[]]