Add envvar for libcuda.so parent dir to CDI spec

[elezar]

This change adds a LIBCUDA_SO_PARENT_DIRECTORY_CONTAINER_PATH envvar to a generated CDI specification. This reports where the libcuda.so.* libraries will be injected into the container.

Fixes #1028

[Copilot]

Pull Request Overview

This PR introduces a LIBCUDA_SO_PARENT_DIRECTORY_CONTAINER_PATH environment variable to the generated CDI specification and implements the required EnvVars interface across multiple discoverer types.

• Adds an EnvVars() method to several discoverers returning empty environment variable lists where appropriate
• Updates the driver library discoverer to extract and report the libcuda.so parent directory
• Adjusts tests to validate that the new environment variable is being injected into container edits

Reviewed Changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pkg/nvcdi/workarounds-device-folder-permissions.go	Adds EnvVars() method returning nil, consistent with other discoverers
pkg/nvcdi/driver-nvml.go	Updates NewDriverLibraryDiscoverer and getVersionLibs to extract the libcuda.so parent directory and append the environment variable
internal/platform-support/dgpu/nvsandboxutils.go; internal/platform-support/dgpu/by-path-hooks.go	Implements EnvVars() returning nil, maintaining interface consistency
internal/edits/edits.go	Adds processing of EnvVars into container edits
internal/discover/*	Updates Discover implementations (none, list, hooks, first-valid, envvar, cache, discover_mock, discover) to support the new EnvVars() interface method
cmd/nvidia-ctk/cdi/generate/generate_test.go; cmd/nvidia-ctk-installer/container/toolkit/toolkit_test.go	Updates tests to verify injection of LIBCUDA_SO_PARENT_DIRECTORY_CONTAINER_PATH in container edits

[ArangoGutierrez]

I am more of a Key/Value mind, but not a blocker.

[elezar]

From https://wiki.debian.org/EnvironmentVariables#:~:text=Variables%20are%20defined,the%20terminal%20session.

Variables are defined with name-value pairs: NAME=any string as value. The variable name is usually in capital letters. Anything that follows the equal-sign is considered the variable's value until the terminating line feed character. Variables can be defined ad hoc in a terminal by writing the appropriate command. In Bash this would be export MYVAL="Hello world". In this case the variable stays defined until the end of the terminal session.

[coveralls]

Pull Request Test Coverage Report for Build 15585739792

Details

• 3 of 89 (3.37%) changed or added relevant lines in 12 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.2%) to 33.367%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/discover/hooks.go	0	3	0.0%
internal/discover/none.go	0	3	0.0%
internal/platform-support/dgpu/by-path-hooks.go	0	3	0.0%
internal/platform-support/dgpu/nvsandboxutils.go	0	3	0.0%
pkg/nvcdi/workarounds-device-folder-permissions.go	0	3	0.0%
internal/edits/edits.go	3	7	42.86%
internal/edits/envvar.go	0	8	0.0%
internal/discover/first-valid.go	0	9	0.0%
internal/discover/list.go	0	10	0.0%
internal/discover/cache.go	0	11	0.0%

Totals
Change from base Build 15585515442:	-0.2%
Covered Lines:	4275
Relevant Lines:	12812

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💛 - Coveralls