CLI plugins error handling

[stanislavHamara]

Problem Description

If a user has an old version of docker that does not include e.g. docker scout or docker ai commands and the extension relies on them, we just error out "silently" in the console.

Proposed Solution

This PR introduces an error message being shown when a particular sub command of docker is not available.

Proof of Work

TBD once we get a correct error message

[Copilot]

Pull Request Overview

This PR improves the CLI plugins' error handling by providing explicit error messages when unsupported Docker subcommands are encountered. Key changes include:

• Introducing a helper function (spawnDockerCommand) to handle Docker process spawning and error propagation.
• Refactoring command registrations to use the new helper for both build and scout commands.
• Updating settings and prompt logic to disable repetitive error prompts.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/utils/spawnDockerCommand.ts	Adds a centralized function to spawn Docker commands and handle errors.
src/utils/settings.ts	Provides helper functions to access and update Docker extension settings.
src/utils/prompt.ts	Updates user prompt functions and introduces an error message function for unknown commands.
src/utils/os.ts	Implements functions to determine the Docker Desktop path and verify its installation.
src/utils/monitor.ts	Refactors Docker engine checking to use the new spawn helper and removes redundant logic.
src/extension.ts	Refactors command registration to use the new spawn helper, ensuring consistent error handling.

[stanislavHamara]

@aevesdocker could we please get an error message for when an extension tries to run a docker subcommand like docker scout or docker ai but it is not available because the user is running an older version of Docker Desktop from before that command was introduced?

[rcjsuen]

it is not available because the user is running an older version of Docker Desktop from before that command was introduced?

1. It might be unavailable because the user installed Docker CE instead of installing Docker Desktop (likely case on Linux). We can reuse promptInstallDesktop in that case although the wording would be different of course.
2. For the Docker Desktop prompts, Varun had mentioned to me we should show them based on the docker.extension.dockerEngineAvailabilityPrompt setting so we will need to add a conditional here similar to checkForDockerEngine. Sorry for not making that clear earlier.

[stanislavHamara]

For 2 are we just happy with the fact that if the user sets docker.extension.dockerEngineAvailabilityPrompt to false they will not get a prompt regardless of if it's docker engine missing or they are running an unavailable command?

[rcjsuen]

For 2 are we just happy with the fact that if the user sets docker.extension.dockerEngineAvailabilityPrompt to false they will not get a prompt regardless of if it's docker engine missing or they are running an unavailable command?

You got it. 👍 I think the idea is "if I have it set to false do not tell me to open or install or update Docker Desktop".

[aevesdocker]

so we all good, or still need me?

[stanislavHamara]

I think we still need one for the case:

It might be unavailable because the user installed Docker CE instead of installing Docker Desktop (likely case on Linux). We can reuse promptInstallDesktop in that case although the wording would be different of course.

[rcjsuen]

We can discuss this during standup to try and get a grasp on all the possibilities.

[rcjsuen]

@stanislavHamara We have three different cases here:

1. docker is not found and Node.js throws that ENOENT error
   • use the promptInstallDesktop function to prompt the user to install Docker Desktop if the user wants to be prompted (per getExtensionSetting('dockerEngineAvailabilityPrompt'))
2. docker scout is not found and we get the non-zero exit code (which suggests docker itself is installed) and isDockerDesktopInstalled returns false, this is likely the Linux use case
   • similar to 1 above, we can prompt the user about this but we need a separate, distinct message from Allie first
3. the reverse case of 2, isDockerDesktopInstalled returns true
   • as discussed on the call, this might not even be a real problem so we will just ignore this for now

@aevesdocker We need your help with 2 above.

vscode-extension/src/utils/prompt.ts

Lines 59 to 63 in 23dc878

	const response = await vscode.window.showInformationMessage(
	'Docker is not running. To get help with your Dockerfile, install Docker.',
	"Don't show again",
	'Install Docker Desktop',
	);

To help jog your memory, these are the strings we use for the case where "Docker is not installed you should install Docker Desktop". This time we need a message to convey that Docker Scout could not be found and you can get it if you install Docker Desktop (without mentioning that Docker is not running as we know they have the docker CLI installed in this particular case).

If any of the above is unclear, please let me know. :)

[aevesdocker]

So something simple like

Docker Scout is not available. To access Docker Scout's features, install Docker Desktop.
with the same action options as above - Don't show again/Install Docker Desktop

?

[rcjsuen]

@aevesdocker That sounds fine to me. 👍 Thanks!

[rcjsuen]

This refactoring is a good start and we can make further changes after this is merged.