cli: hint when install-runner options are ignored

[YasharthPanwar-2003]

Summary

• Add a reinstall hint when install-runner finds an existing running Model Runner container
• Show the hint only when the user explicitly passed --backend or --gpu
• Preserve the existing “already running” message and return behavior
• Add focused tests for the new hint-generation logic

Fixes #907

What changed

• Added commandFlagChanged to check whether a Cobra flag was explicitly changed
• Added existingRunnerOptionsHint to build the reinstall command hint
• Updated the existing ctrID != "" branch to print the hint after the current already-running message
• Added cmd/cli/commands/install_runner_existing_options_hint_test.go

What this does not change

• Does not automatically reinstall or recreate an existing runner
• Does not change reinstall-runner behavior
• Does not change backend selection logic
• Does not change GPU probing or CUDA/vLLM runtime behavior
• Does not attempt to fully fix WSL2 CUDA/vLLM execution

Tests added

• No hint when --backend and --gpu were not explicitly passed
• Backend-only hint
• GPU-only CUDA hint
• Backend + CUDA hint
• Explicit --gpu none hint
• Defensive flag-check cases

Validation

• go test ./cmd/cli/commands -run "TestInstallRunner|TestExistingRunnerOptionsHint|TestCommandFlagChanged" -v
• go test ./cmd/cli/commands -v`
• go test ./...
• make validate-all

Validation details

• go.mod tidy check passed
• golangci-lint run ./... passed with 0 issues
• go test -race ./... passed
• Shellcheck validation passed
• .versions is in sync with Dockerfile ARGs

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[gemini-code-assist]

Code Review

This pull request introduces a mechanism to provide users with a hint command when they attempt to install or start a Model Runner that is already active but with different configuration flags. It includes a new helper function to detect flag changes and comprehensive unit tests for the hint generation logic. Feedback was provided regarding a potential security and correctness issue where user-provided flag values are not properly escaped in the suggested command string, which could lead to issues if values contain spaces or malicious characters.

[gemini-code-assist]

Critical

• The suggested command string is constructed using unvalidated and unescaped user input from flags. This poses a security risk (command injection if a user copy-pastes a malicious string) and a correctness issue if values contain spaces. Values should be properly quoted/escaped for the shell.

Following the Security principle (Repository Style Guide, line 12), input must be handled safely when crossing boundaries, including when displayed back to the user as a suggested command.

Suggested change

	if backendChanged && opts.backend != "" {
	reinstallArgs = append(reinstallArgs, "--backend", opts.backend)
	}
	if gpuChanged && opts.gpuMode != "" {
	reinstallArgs = append(reinstallArgs, "--gpu", opts.gpuMode)
	}
	if backendChanged && opts.backend != "" {
	reinstallArgs = append(reinstallArgs, "--backend", fmt.Sprintf("%q", opts.backend))
	}
	if gpuChanged && opts.gpuMode != "" {
	reinstallArgs = append(reinstallArgs, "--gpu", fmt.Sprintf("%q", opts.gpuMode))
	}

[sathiraumesh]

Better if you can put the tests in existing install-runner_test.go file

[YasharthPanwar-2003]

Ok , I do that. May you please help me with if the gemini suggested changes to be done in code ?

[sathiraumesh]

@YasharthPanwar-2003 if you check the code both of theopts.backend and the opts.gpuMode are validated by predefined sepcs. so it won't be a problem though but for defense in future its better to do the suggestion by gemini here like change to the below

if backendChanged && opts.backend != "" {
		reinstallArgs = append(reinstallArgs, "--backend", fmt.Sprintf("%q", opts.backend))
	}
	if gpuChanged && opts.gpuMode != "" {
		reinstallArgs = append(reinstallArgs, "--gpu", fmt.Sprintf("%q", opts.gpuMode))
	}

Its always important to double check what these analyzers suggest because it sometimes can be wrong. Always try to check whether its the case

[sathiraumesh]

and test this feature in local as well :)

[YasharthPanwar-2003]

I dont have NVIDIA gpu cuda , but I tested it over wsl2 Ubuntu 22.04 for cpu only , after the new updation I will test again!

[ericcurtin]

@YasharthPanwar-2003 thanks for looking at this, is the bot comment worth fixing?

[ericcurtin]

You will need to fix CI also