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 version available is 2.37.0-rc, and there are multiple historical versions of the vmmigration documentation accessible, ranging from version 2.36.0 down to 2.11.0."],["By default, the client libraries will automatically use Application Default Credentials to authenticate to the google cloud services unless otherwise configured."],["Authentication defaults can be overridden by supplying the UnifiedCredentialsOption, which may be used in order to load a service account key file, as shown in the example code."],["It's important to consult the \"Best practices for managing service account keys\" for more details, as the provided code is an example chosen for its relative simplicity."],["Further details can be found in the Authentication Components documentation on how to create google::cloud::Credentials objects."]]],[]]
