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 theEndpointOption(which defaults to "osconfig.googleapis.com") used byMakeAgentEndpointServiceConnection().
GOOGLE_CLOUD_CPP_OS_CONFIG_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "osconfig.googleapis.com") used byMakeOsConfigServiceConnection().
GOOGLE_CLOUD_CPP_OS_CONFIG_ZONAL_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "osconfig.googleapis.com") used byMakeOsConfigZonalServiceConnection().
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 setGOOGLE_CLOUD_CPP_ENABLE_CLOGto 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"]],[["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 2025-09-04 UTC."],[[["\u003cp\u003eThe latest release candidate version is 2.37.0-rc, and a list of versions ranging from 2.36.0 down to 2.11.0 are available with associated documentation links.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables can be used to configure the behavior of the library, specifically for troubleshooting and setting up the library.\u003c/p\u003e\n"],["\u003cp\u003eEndpoint overrides for services such as AgentEndpointService, OsConfigService, and OsConfigZonalService can be configured using specific environment variables.\u003c/p\u003e\n"],["\u003cp\u003eTracing and logging for gRPC calls can be enabled and customized via \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING\u003c/code\u003e, \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e, and \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e environment variables.\u003c/p\u003e\n"],["\u003cp\u003eWhile \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e configures the GCP project in examples and tests, it does not have any effect on the library's functionality.\u003c/p\u003e\n"]]],[],null,["Version 2.24.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/osconfig/latest/osconfig-env)\n- [2.41.0](/cpp/docs/reference/osconfig/2.41.0/osconfig-env)\n- [2.40.0](/cpp/docs/reference/osconfig/2.40.0/osconfig-env)\n- [2.39.0](/cpp/docs/reference/osconfig/2.39.0/osconfig-env)\n- [2.38.0](/cpp/docs/reference/osconfig/2.38.0/osconfig-env)\n- [2.37.0](/cpp/docs/reference/osconfig/2.37.0/osconfig-env)\n- [2.36.0](/cpp/docs/reference/osconfig/2.36.0/osconfig-env)\n- [2.35.0](/cpp/docs/reference/osconfig/2.35.0/osconfig-env)\n- [2.34.0](/cpp/docs/reference/osconfig/2.34.0/osconfig-env)\n- [2.33.0](/cpp/docs/reference/osconfig/2.33.0/osconfig-env)\n- [2.32.0](/cpp/docs/reference/osconfig/2.32.0/osconfig-env)\n- [2.31.0](/cpp/docs/reference/osconfig/2.31.0/osconfig-env)\n- [2.30.0](/cpp/docs/reference/osconfig/2.30.0/osconfig-env)\n- [2.29.0](/cpp/docs/reference/osconfig/2.29.0/osconfig-env)\n- [2.28.0](/cpp/docs/reference/osconfig/2.28.0/osconfig-env)\n- [2.27.0](/cpp/docs/reference/osconfig/2.27.0/osconfig-env)\n- [2.26.0](/cpp/docs/reference/osconfig/2.26.0/osconfig-env)\n- [2.25.1](/cpp/docs/reference/osconfig/2.25.1/osconfig-env)\n- [2.24.0](/cpp/docs/reference/osconfig/2.24.0/osconfig-env)\n- [2.23.0](/cpp/docs/reference/osconfig/2.23.0/osconfig-env)\n- [2.22.1](/cpp/docs/reference/osconfig/2.22.1/osconfig-env)\n- [2.21.0](/cpp/docs/reference/osconfig/2.21.0/osconfig-env)\n- [2.20.0](/cpp/docs/reference/osconfig/2.20.0/osconfig-env)\n- [2.19.0](/cpp/docs/reference/osconfig/2.19.0/osconfig-env)\n- [2.18.0](/cpp/docs/reference/osconfig/2.18.0/osconfig-env)\n- [2.17.0](/cpp/docs/reference/osconfig/2.17.0/osconfig-env)\n- [2.16.0](/cpp/docs/reference/osconfig/2.16.0/osconfig-env)\n- [2.15.1](/cpp/docs/reference/osconfig/2.15.1/osconfig-env)\n- [2.14.0](/cpp/docs/reference/osconfig/2.14.0/osconfig-env)\n- [2.13.0](/cpp/docs/reference/osconfig/2.13.0/osconfig-env)\n- [2.12.0](/cpp/docs/reference/osconfig/2.12.0/osconfig-env)\n- [2.11.0](/cpp/docs/reference/osconfig/2.11.0/osconfig-env) \n\nEnvironment Variables\n=====================\n\nA 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.\n\nEndpoint Overrides\n------------------\n\n- `GOOGLE_CLOUD_CPP_AGENT_ENDPOINT_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"osconfig.googleapis.com\") used by `MakeAgentEndpointServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_OS_CONFIG_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"osconfig.googleapis.com\") used by `MakeOsConfigServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_OS_CONFIG_ZONAL_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"osconfig.googleapis.com\") used by `MakeOsConfigZonalServiceConnection()`.\n\n###### See Also\n\n[`google::cloud::EndpointOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1EndpointOption.html)\n\nLogging\n-------\n\n`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.\n\n###### See Also\n\n[`google::cloud::TracingComponentsOption`](about:invalid#zCSafez)`GOOGLE_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.\n\n###### See Also\n\n[`google::cloud::GrpcTracingOptionsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1GrpcTracingOptionsOption.html)`GOOGLE_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.\n\n###### See Also\n\n[`google::cloud::LogBackend`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1LogBackend.html)\n\n###### See Also\n\n[`google::cloud::LogSink`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1LogSink.html)\n\nSetting the Default Project\n---------------------------\n\n`GOOGLE_CLOUD_PROJECT=...`: is used in examples and integration tests to configure the GCP project. This has no effect in the library."]]
