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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 available versions, ranging from 2.11.0 up to the latest release candidate 2.37.0-rc, for the specified software component.\u003c/p\u003e\n"],["\u003cp\u003eThe library's behavior can be configured using environment variables, which is particularly helpful for troubleshooting, and functions can configure the same behavior in code.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables like \u003ccode\u003eGOOGLE_CLOUD_CPP_ENVIRONMENTS_ENDPOINT\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_IMAGE_VERSIONS_ENDPOINT\u003c/code\u003e allow overriding the default endpoints used by specific connections.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled via \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and additional logging to the program's console can be activated with \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e environment variable is utilized in examples and integration tests for configuring the GCP project, although it does not affect the library itself.\u003c/p\u003e\n"]]],[],null,[]]
