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_AGENT_ENDPOINT_SERVICE_ENDPOINT=... overrides the EndpointOption (which defaults to "osconfig.googleapis.com") used by MakeAgentEndpointServiceConnection().
GOOGLE_CLOUD_CPP_OS_CONFIG_SERVICE_ENDPOINT=... overrides the EndpointOption (which defaults to "osconfig.googleapis.com") used by MakeOsConfigServiceConnection().
GOOGLE_CLOUD_CPP_OS_CONFIG_ZONAL_SERVICE_ENDPOINT=... overrides the EndpointOption (which defaults to "osconfig.googleapis.com") used by MakeOsConfigZonalServiceConnection().
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::TracingComponentsOptionGOOGLE_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"]],[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-07-26 UTC."],[[["The latest release candidate version available is 2.37.0-rc, while the currently presented stable version is 2.16.0."],["This page details environment variables that can be utilized to customize the library's operation, including options for troubleshooting and logging."],["Endpoint overrides are available through specific environment variables, enabling users to modify the default endpoints used by various service connections like `MakeAgentEndpointServiceConnection()`."],["Environment variables such as `GOOGLE_CLOUD_CPP_ENABLE_TRACING` and `GOOGLE_CLOUD_CPP_ENABLE_CLOG` allow for detailed tracing of gRPC calls and enabling logging within the library."],["`GOOGLE_CLOUD_PROJECT` environment variable is used for examples and integration tests, but does not affect library behavior."]]],[]]
