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::config_v1::ConfigClient(
google::cloud::config_v1::MakeConfigConnection(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."],[[["This document details how to override the default authentication credentials used by client libraries when interacting with Google Cloud Services."],["The default authentication method utilizes Application Default Credentials, but this can be overridden using the `UnifiedCredentialsOption`."],["A practical example demonstrates loading a service account key file to override the default credentials."],["The document provides links to further resources, including \"Best practices for managing service account keys\" and \"Authentication Components\"."],["This webpage provides a list of links to documentation for different versions of the software, from 2.16.0 up to the latest release candidate 2.37.0-rc."]]],[]]
