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::migrationcenter_v1::MigrationCenterClient(
google::cloud::migrationcenter_v1::MakeMigrationCenterConnection(
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."],[[["The latest version available is 2.37.0-rc, with numerous other versions, starting at 2.36.0 and going all the way to 2.13.0, available for selection."],["The client libraries typically use Application Default Credentials for Google Cloud Services authentication, but this default can be overridden."],["You can override the default authentication by using the `UnifiedCredentialsOption`, as shown in the example code which demonstrates how to load a service account key file."],["For detailed information on managing service account keys, refer to the \"Best practices for managing service account keys\" guide, and for factory functions to create credentials objects, the \"Authentication Components\" page is recommended."],["Each version listed in this document pertains to the subject \"migrationcenter-override-authentication\" which is the override of the authentication credentials."]]],[]]
