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::vmmigration_v1::VmMigrationClient(
google::cloud::vmmigration_v1::MakeVmMigrationConnection(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."],[[["This page lists the available versions of the vmmigration documentation, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["The latest release candidate version is 2.37.0-rc, which is accessible via a provided link at the top of the listed versions."],["The content demonstrates how to override default authentication credentials for Google Cloud services using a service account key file and the `UnifiedCredentialsOption`."],["Users can find additional details on authentication by visiting the \"Authentication Components\" link provided in the \"See Also\" section."],["The example provided uses minimal error handling and users should consult the best practices for managing service account keys for more details."]]],[]]
