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_LOOKUP_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "servicedirectory.googleapis.com") used byMakeLookupServiceConnection().
GOOGLE_CLOUD_CPP_REGISTRATION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "servicedirectory.googleapis.com") used byMakeRegistrationServiceConnection().
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::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 2025-09-04 UTC."],[[["\u003cp\u003eThis document provides a comprehensive list of environment variables for configuring the behavior of the C++ Service Directory library, along with links to relevant documentation for each.\u003c/p\u003e\n"],["\u003cp\u003eThe library supports endpoint overrides for both the Lookup Service and Registration Service via \u003ccode\u003eGOOGLE_CLOUD_CPP_LOOKUP_SERVICE_ENDPOINT\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_REGISTRATION_SERVICE_ENDPOINT\u003c/code\u003e variables, respectively.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled using \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, which provides detailed request and response logging, often in conjunction with the \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e variable.\u003c/p\u003e\n"],["\u003cp\u003eThe document lists a historical set of versions of the service, with \u003ccode\u003e2.37.0-rc\u003c/code\u003e being the latest release candidate, and version \u003ccode\u003e2.35.0\u003c/code\u003e being the default version highlighted on this specific page.\u003c/p\u003e\n"],["\u003cp\u003eIt also discusses how logging, although always available, can be configured to print via \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e, and tracing behavior can be altered with \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS=...\u003c/code\u003e.\u003c/p\u003e\n"]]],[],null,["Version 2.35.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/servicedirectory/latest/servicedirectory-env)\n- [2.41.0](/cpp/docs/reference/servicedirectory/2.41.0/servicedirectory-env)\n- [2.40.0](/cpp/docs/reference/servicedirectory/2.40.0/servicedirectory-env)\n- [2.39.0](/cpp/docs/reference/servicedirectory/2.39.0/servicedirectory-env)\n- [2.38.0](/cpp/docs/reference/servicedirectory/2.38.0/servicedirectory-env)\n- [2.37.0](/cpp/docs/reference/servicedirectory/2.37.0/servicedirectory-env)\n- [2.36.0](/cpp/docs/reference/servicedirectory/2.36.0/servicedirectory-env)\n- [2.35.0](/cpp/docs/reference/servicedirectory/2.35.0/servicedirectory-env)\n- [2.34.0](/cpp/docs/reference/servicedirectory/2.34.0/servicedirectory-env)\n- [2.33.0](/cpp/docs/reference/servicedirectory/2.33.0/servicedirectory-env)\n- [2.32.0](/cpp/docs/reference/servicedirectory/2.32.0/servicedirectory-env)\n- [2.31.0](/cpp/docs/reference/servicedirectory/2.31.0/servicedirectory-env)\n- [2.30.0](/cpp/docs/reference/servicedirectory/2.30.0/servicedirectory-env)\n- [2.29.0](/cpp/docs/reference/servicedirectory/2.29.0/servicedirectory-env)\n- [2.28.0](/cpp/docs/reference/servicedirectory/2.28.0/servicedirectory-env)\n- [2.27.0](/cpp/docs/reference/servicedirectory/2.27.0/servicedirectory-env)\n- [2.26.0](/cpp/docs/reference/servicedirectory/2.26.0/servicedirectory-env)\n- [2.25.1](/cpp/docs/reference/servicedirectory/2.25.1/servicedirectory-env)\n- [2.24.0](/cpp/docs/reference/servicedirectory/2.24.0/servicedirectory-env)\n- [2.23.0](/cpp/docs/reference/servicedirectory/2.23.0/servicedirectory-env)\n- [2.22.1](/cpp/docs/reference/servicedirectory/2.22.1/servicedirectory-env)\n- [2.21.0](/cpp/docs/reference/servicedirectory/2.21.0/servicedirectory-env)\n- [2.20.0](/cpp/docs/reference/servicedirectory/2.20.0/servicedirectory-env)\n- [2.19.0](/cpp/docs/reference/servicedirectory/2.19.0/servicedirectory-env)\n- [2.18.0](/cpp/docs/reference/servicedirectory/2.18.0/servicedirectory-env)\n- [2.17.0](/cpp/docs/reference/servicedirectory/2.17.0/servicedirectory-env)\n- [2.16.0](/cpp/docs/reference/servicedirectory/2.16.0/servicedirectory-env)\n- [2.15.1](/cpp/docs/reference/servicedirectory/2.15.1/servicedirectory-env)\n- [2.14.0](/cpp/docs/reference/servicedirectory/2.14.0/servicedirectory-env)\n- [2.13.0](/cpp/docs/reference/servicedirectory/2.13.0/servicedirectory-env)\n- [2.12.0](/cpp/docs/reference/servicedirectory/2.12.0/servicedirectory-env)\n- [2.11.0](/cpp/docs/reference/servicedirectory/2.11.0/servicedirectory-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_LOOKUP_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"servicedirectory.googleapis.com\") used by `MakeLookupServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_REGISTRATION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"servicedirectory.googleapis.com\") used by `MakeRegistrationServiceConnection()`.\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::LoggingComponentsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1LoggingComponentsOption.html)`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."]]
