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_CLOUD_CHANNEL_REPORTS_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "cloudchannel.googleapis.com") used byMakeCloudChannelReportsServiceConnection().
GOOGLE_CLOUD_CPP_CLOUD_CHANNEL_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "cloudchannel.googleapis.com") used byMakeCloudChannelServiceConnection().
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\u003eThis page provides documentation for various versions of the C++ library, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables are detailed for configuring the library's behavior, specifically highlighting the ability to override endpoints for the Cloud Channel Reports and Service.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation outlines how to enable gRPC tracing and logging using environment variables, as well as providing configuration options for more granular tracing control.\u003c/p\u003e\n"],["\u003cp\u003eThere are multiple links provided to the google cloud documentation so that you may learn more about Tracing and Logging for Cloud, as well as the ability to override default endpoints.\u003c/p\u003e\n"],["\u003cp\u003eSetting the default GCP project can be achieved through the environment variable \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e, but this is for examples and tests, not library functionality.\u003c/p\u003e\n"]]],[],null,["Version 2.21.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/channel/latest/channel-env)\n- [2.41.0](/cpp/docs/reference/channel/2.41.0/channel-env)\n- [2.40.0](/cpp/docs/reference/channel/2.40.0/channel-env)\n- [2.39.0](/cpp/docs/reference/channel/2.39.0/channel-env)\n- [2.38.0](/cpp/docs/reference/channel/2.38.0/channel-env)\n- [2.37.0](/cpp/docs/reference/channel/2.37.0/channel-env)\n- [2.36.0](/cpp/docs/reference/channel/2.36.0/channel-env)\n- [2.35.0](/cpp/docs/reference/channel/2.35.0/channel-env)\n- [2.34.0](/cpp/docs/reference/channel/2.34.0/channel-env)\n- [2.33.0](/cpp/docs/reference/channel/2.33.0/channel-env)\n- [2.32.0](/cpp/docs/reference/channel/2.32.0/channel-env)\n- [2.31.0](/cpp/docs/reference/channel/2.31.0/channel-env)\n- [2.30.0](/cpp/docs/reference/channel/2.30.0/channel-env)\n- [2.29.0](/cpp/docs/reference/channel/2.29.0/channel-env)\n- [2.28.0](/cpp/docs/reference/channel/2.28.0/channel-env)\n- [2.27.0](/cpp/docs/reference/channel/2.27.0/channel-env)\n- [2.26.0](/cpp/docs/reference/channel/2.26.0/channel-env)\n- [2.25.1](/cpp/docs/reference/channel/2.25.1/channel-env)\n- [2.24.0](/cpp/docs/reference/channel/2.24.0/channel-env)\n- [2.23.0](/cpp/docs/reference/channel/2.23.0/channel-env)\n- [2.22.1](/cpp/docs/reference/channel/2.22.1/channel-env)\n- [2.21.0](/cpp/docs/reference/channel/2.21.0/channel-env)\n- [2.20.0](/cpp/docs/reference/channel/2.20.0/channel-env)\n- [2.19.0](/cpp/docs/reference/channel/2.19.0/channel-env)\n- [2.18.0](/cpp/docs/reference/channel/2.18.0/channel-env)\n- [2.17.0](/cpp/docs/reference/channel/2.17.0/channel-env)\n- [2.16.0](/cpp/docs/reference/channel/2.16.0/channel-env)\n- [2.15.1](/cpp/docs/reference/channel/2.15.1/channel-env)\n- [2.14.0](/cpp/docs/reference/channel/2.14.0/channel-env)\n- [2.13.0](/cpp/docs/reference/channel/2.13.0/channel-env)\n- [2.12.0](/cpp/docs/reference/channel/2.12.0/channel-env)\n- [2.11.0](/cpp/docs/reference/channel/2.11.0/channel-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_CLOUD_CHANNEL_REPORTS_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"cloudchannel.googleapis.com\") used by `MakeCloudChannelReportsServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_CLOUD_CHANNEL_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"cloudchannel.googleapis.com\") used by `MakeCloudChannelServiceConnection()`.\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`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1TracingComponentsOption.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."]]
