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_DEVICE_MANAGER_ENDPOINT=... overrides the EndpointOption (which defaults to "cloudiot.googleapis.com") used by MakeDeviceManagerConnection().
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"]],[["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 2025-03-21 UTC."],[[["The library's behavior can be configured using environment variables or corresponding functions in the code, with environment variables being particularly useful for troubleshooting."],["`GOOGLE_CLOUD_CPP_DEVICE_MANAGER_ENDPOINT` can be utilized to override the default endpoint used by `MakeDeviceManagerConnection()`, which is \"cloudiot.googleapis.com\"."],["Enabling gRPC call tracing is done by setting `GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`, and to actually see the output on the console, `GOOGLE_CLOUD_CPP_ENABLE_CLOG` should also be set."],["`GOOGLE_CLOUD_CPP_TRACING_OPTIONS` is used to customize the gRPC tracing output, for instance, how messages are displayed or whether fields are truncated."],["Setting the `GOOGLE_CLOUD_PROJECT` environment variable configures the GCP project in examples and integration tests, but does not impact the library's function."]]],[]]
