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::vision_v1::ImageAnnotatorClient(
google::cloud::vision_v1::MakeImageAnnotatorConnection(options));
}
Follow these links to find examples for other *Client classes:
[[["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 details how to override the default Application Default Credentials (ADC) for authenticating with Google Cloud Services, which is necessary in certain cases."],["The latest available version is 2.37.0-rc, and there is a list of previous versions including 2.36.0, 2.35.0 and so on, all the way back to version 2.11.0."],["You can override default authentication by using the `UnifiedCredentialsOption` and loading a service account key file, as demonstrated in the provided example code."],["Examples for `vision_v1::ImageAnnotatorClient` and `vision_v1::ProductSearchClient` classes are provided via links for further details on using service accounts."],["The guide on best practices for managing service account keys is linked for further consultation."]]],[]]
