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::functions_v1::CloudFunctionsServiceClient(
google::cloud::functions_v1::MakeCloudFunctionsServiceConnection(
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 2025-03-21 UTC."],[[["This page documents how to override the default Application Default Credentials (ADC) used by the client libraries for authenticating with Google Cloud Services."],["The most recent version of the documentation provided is 2.37.0-rc, and there are multiple previous versions that can be navigated from 2.36.0 all the way down to 2.11.0."],["Authentication can be overridden by providing a `UnifiedCredentialsOption`, such as loading a service account key file as demonstrated in the provided code snippet."],["There are examples for `functions_v1::CloudFunctionsServiceClient` and `functions_v2::FunctionServiceClient` that are easily accessible through the links provided in this document."],["For more complex scenarios, it is recommended to consult the \"Best practices for managing service account keys\" guide and the Authentication Components documentation."]]],[]]
