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::storageinsights_v1::StorageInsightsClient(
google::cloud::storageinsights_v1::MakeStorageInsightsConnection(
options));
}
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThe latest version available is 2.37.0-rc, with numerous other versions, down to 2.11.0, also listed for reference.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries, by default, authenticate with Google Cloud Services using Application Default Credentials, unless otherwise specified.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default authentication method by using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, for instance, to explicitly load a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe provided code snippet illustrates how to load a service account key file using \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e, serving as a simplified example for understanding the process.\u003c/p\u003e\n"],["\u003cp\u003eFor additional details on managing service account keys and the creation of \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, consult the linked documentation on best practices and authentication components.\u003c/p\u003e\n"]]],[],null,[]]
