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::datafusion_v1::DataFusionClient(
google::cloud::datafusion_v1::MakeDataFusionConnection(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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThis page provides documentation for overriding default authentication credentials when interacting with Google Cloud Services, specifically within the context of the DataFusion client library.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries typically rely on Application Default Credentials (ADC) for authentication, but this can be overridden using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eA service account key file can be loaded to override the default credentials, as demonstrated in the provided example using \u003ccode\u003eMakeServiceAccountCredentials\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe latest datafusion version being referenced in the documentation is \u003ccode\u003e2.37.0-rc\u003c/code\u003e while the lowest version referenced is \u003ccode\u003e2.13.0\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation references the \u003ccode\u003eAuthentication Components\u003c/code\u003e and \u003ccode\u003eBest practices for managing service account keys\u003c/code\u003e guides for further details on how to authenticate.\u003c/p\u003e\n"]]],[],null,[]]
