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::essentialcontacts_v1::EssentialContactsServiceClient(
google::cloud::essentialcontacts_v1::
MakeEssentialContactsServiceConnection(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 release candidate version is 2.37.0-rc, and there are a range of versions available from 2.36.0 down to 2.12.0 for EssentialContacts."],["The client libraries typically use Application Default Credentials for Google Cloud Services authentication, but this can be overridden if necessary."],["You can override the default credentials by using the UnifiedCredentialsOption, such as loading a service account key file explicitly, which is shown in the provided example code."],["For detailed information on managing service account keys, it's recommended to consult the \"Best practices for managing service account keys\" guide."],["The \"Authentication Components\" section offers further insight on the factory functions that help create `google::cloud::Credentials` objects."]]],[]]
