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::vpcaccess_v1::VpcAccessServiceClient(
google::cloud::vpcaccess_v1::MakeVpcAccessServiceConnection(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 document provides a list of available versions for VPC Access, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc, with links to documentation for each version."],["The client libraries typically use Application Default Credentials (ADC) for authentication with Google Cloud Services, but you can override this default if needed."],["Overriding default authentication can be achieved by providing the UnifiedCredentialsOption, as demonstrated by loading a service account key file, using the MakeServiceAccountCredentials method."],["Refer to the \"Best practices for managing service account keys\" guide for detailed information and the \"Authentication Components\" documentation for more information on creating `google::cloud::Credentials` objects."]]],[]]
