namespace spanner = ::google::cloud::spanner;
[](std::string const& project_id, std::string const& instance_id,
std::string const& database_id, std::string const& keyfile) {
auto is = std::ifstream(keyfile);
is.exceptions(std::ios::badbit);
auto contents = std::string(std::istreambuf_iterator<char>(is.rdbuf()), {});
auto options =
google::cloud::Options{}.set<google::cloud::UnifiedCredentialsOption>(
google::cloud::MakeServiceAccountCredentials(contents));
return spanner::Client(spanner::MakeConnection(
spanner::Database(project_id, instance_id, database_id), options));
}
Keep in mind that we chose this as an example because it is relatively easy to understand. Consult the [Best practices for managing service account keys] guide for more details.
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"]],[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-22 UTC."],[[["\u003cp\u003eThis document provides access to various versions of the Spanner C++ client library, with version 2.37.0-rc being the latest release candidate.\u003c/p\u003e\n"],["\u003cp\u003eThe library versions range from 2.11.0 up to the latest release candidate, offering a comprehensive view of the library's development history, and all version links are specific to the \u003ccode\u003espanner-auth-example\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe content demonstrates how to override the default authentication configuration by using \u003ccode\u003egoogle::cloud::UnifiedCredentialsOption\u003c/code\u003e and loading a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe document offers links to examples for \u003ccode\u003eDatabaseAdminClient\u003c/code\u003e and \u003ccode\u003eInstanceAdminClient\u003c/code\u003e classes, showing how to use them with service accounts within the context of the 2.23.0 version.\u003c/p\u003e\n"],["\u003cp\u003eIt's advised to refer to the "Best practices for managing service account keys" guide for detailed information on handling service account credentials, and that the provided example is for easy understanding.\u003c/p\u003e\n"]]],[],null,[]]
