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::datastream_v1::DatastreamClient(
google::cloud::datastream_v1::MakeDatastreamConnection(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 overriding default authentication credentials when using Google Cloud client libraries, with version-specific information ranging from 2.11.0 to 2.37.0-rc."],["The default authentication method utilizes Application Default Credentials, but custom authentication can be implemented when needed."],["Overriding authentication is achieved by setting the `UnifiedCredentialsOption` and the page demonstrates doing so through loading a service account key file."],["Users should consult the best practices guide for managing service account keys for more details on key management."],["Additional details on creating `google::cloud::Credentials` objects can be found in the Authentication Components documentation."]]],[]]
