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."],[[["The latest release candidate version available is 2.37.0-rc, while the most recently released version is 2.36.0, and the webpage lists available releases down to version 2.11.0."],["The client libraries by default utilize Application Default Credentials for authenticating with Google Cloud Services."],["Users can override the default authentication method by providing a UnifiedCredentialsOption, such as loading a service account key file explicitly."],["The example provided demonstrates how to load a service account key file and create a VmMigrationClient using the specified credentials."],["For more details on managing service account keys and creating Credentials objects, the \"Best practices for managing service account keys\" guide and the \"Authentication Components\" documentation are available."]]],[]]
