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 2025-03-05 UTC."],[[["The latest version available is 2.37.0-rc, with numerous preceding versions down to 2.11.0 also accessible."],["By default, the client libraries use Application Default Credentials for authenticating with Google Cloud Services, but this can be overridden."],["You can override default authentication by using `UnifiedCredentialsOption`, such as loading a service account key file explicitly."],["The provided example demonstrates overriding authentication credentials using a service account key file, which is an easy-to-understand method, but for best practices you can consult the provided guide."],["More information on creating `google::cloud::Credentials` objects can be found in the Authentication Components section."]]],[]]
