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_HUB_SERVICE_ENDPOINT=... overrides the EndpointOption (which defaults to "networkconnectivity.googleapis.com") used by MakeHubServiceConnection().
GOOGLE_CLOUD_CPP_POLICY_BASED_ROUTING_SERVICE_ENDPOINT=... overrides the EndpointOption (which defaults to "networkconnectivity.googleapis.com") used by MakePolicyBasedRoutingServiceConnection().
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 2025-03-05 UTC."],[[["This page details environment variables and configurations for the network connectivity C++ library, with the latest version being 2.37.0-rc and the currently viewed version being 2.34.0."],["Environment variables can override default settings, such as `GOOGLE_CLOUD_CPP_HUB_SERVICE_ENDPOINT` and `GOOGLE_CLOUD_CPP_POLICY_BASED_ROUTING_SERVICE_ENDPOINT`, which change the service endpoints for hub service and policy-based routing respectively."],["Tracing for gRPC calls can be enabled via `GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`, which outputs gRPC requests and responses, and can be further modified with `GOOGLE_CLOUD_CPP_TRACING_OPTIONS`."],["The `GOOGLE_CLOUD_CPP_ENABLE_CLOG=yes` environment variable enables logging within the library, which can be used in tandem with other tracing features to give more detail."],["`GOOGLE_CLOUD_PROJECT` can be used in examples and integration tests to configure the GCP project, but this is not a setting used by the library itself."]]],[]]
