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_ENVIRONMENTS_ENDPOINT=... overrides the EndpointOption (which defaults to "composer.googleapis.com") used by MakeEnvironmentsConnection().
GOOGLE_CLOUD_CPP_IMAGE_VERSIONS_ENDPOINT=... overrides the EndpointOption (which defaults to "composer.googleapis.com") used by MakeImageVersionsConnection().
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"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis document provides a comprehensive list of C++ Composer versions, ranging from the latest release candidate (2.37.0-rc) down to version 2.11.0, with each version linking to its respective documentation.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables can be utilized to modify the behavior of the library, especially useful during the process of troubleshooting issues.\u003c/p\u003e\n"],["\u003cp\u003eSpecific environment variables, \u003ccode\u003eGOOGLE_CLOUD_CPP_ENVIRONMENTS_ENDPOINT\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_IMAGE_VERSIONS_ENDPOINT\u003c/code\u003e, allow users to override default endpoints for Environments and Image Versions connections, respectively.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled using \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and the \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e environment variable can further refine the behavior of this tracing.\u003c/p\u003e\n"],["\u003cp\u003eEnabling logging in the library can be done by setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e which allows the application to output logs to the console.\u003c/p\u003e\n"]]],[],null,[]]
