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::memcache_v1::CloudMemcacheClient(
google::cloud::memcache_v1::MakeCloudMemcacheConnection(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 2025-04-09 UTC."],[[["The latest available release candidate version is 2.37.0-rc, while the most recent fully released version is 2.36.0, and version 2.32.0 is also included."],["This documentation covers how to override default authentication credentials by utilizing the `UnifiedCredentialsOption` for specific cases where the standard Application Default Credentials are not suitable."],["Service account key files can be explicitly loaded to override default credentials, as shown in the provided C++ example code using `google::cloud::MakeServiceAccountCredentials`."],["The documentation includes links to more resources, such as best practices for managing service account keys and details on authentication components to create `google::cloud::Credentials` objects."]]],[]]
