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::channel_v1::CloudChannelServiceClient(
google::cloud::channel_v1::MakeCloudChannelServiceConnection(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 provides documentation for various versions of the C++ client library, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc, specifically for `channel-override-authentication`."],["The client libraries default to using Application Default Credentials for authentication with Google Cloud Services, but this can be overridden."],["Overriding the default credentials can be done by providing the `UnifiedCredentialsOption`, demonstrated by an example that loads a service account key file."],["Examples are available for other `*Client` classes such as `channel_v1::CloudChannelServiceClient` and `channel_v1::CloudChannelReportsServiceClient`."],["The \"Best practices for managing service account keys\" guide and \"Authentication Components\" section are provided as resources to help the user authenticate."]]],[]]