A number of environment variables can be used to configure the behavior of the library. There are also functions to configure this behavior in code. The environment variables are convenient when troubleshooting problems.
Endpoint Overrides
GOOGLE_CLOUD_CPP_OS_LOGIN_SERVICE_ENDPOINT=... overrides the EndpointOption (which defaults to "oslogin.googleapis.com") used by MakeOsLoginServiceConnection().
GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc: turns on tracing for most gRPC calls. The library injects an additional Stub decorator that prints each gRPC request and response. Unless you have configured your own logging backend, you should also set GOOGLE_CLOUD_CPP_ENABLE_CLOG to produce any output on the program's console.
See Also
google::cloud::LoggingComponentsOptionGOOGLE_CLOUD_CPP_TRACING_OPTIONS=...: modifies the behavior of gRPC tracing, including whether messages will be output on multiple lines, or whether string/bytes fields will be truncated.
See Also
google::cloud::GrpcTracingOptionsOptionGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes: turns on logging in the library, basically the library always "logs" but the logging infrastructure has no backend to actually print anything until the application sets a backend or they set this environment variable.
[[["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 2025-04-23 UTC."],[[["This document provides reference information for the OS Login service in C++, outlining various versions and their corresponding documentation links, with version 2.37.0-rc being the latest."],["Environment variables can be leveraged to configure the OS Login library's behavior, and this document describes some of the important ones such as the endpoint overrides, logging options, and default project setting."],["The `GOOGLE_CLOUD_CPP_OS_LOGIN_SERVICE_ENDPOINT` environment variable can override the default endpoint used by `MakeOsLoginServiceConnection()`."],["Tracing of gRPC calls can be enabled using `GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`, and it is recommended to set `GOOGLE_CLOUD_CPP_ENABLE_CLOG` to display the logs on the console."],["While `GOOGLE_CLOUD_PROJECT` environment variable is used in examples and integration tests to set a default GCP project, it has no effect in the library."]]],[]]
