Investigate and break down tasks on how to configure private extensions marketplace for Self-managed users

MR: Enable VS Code private extensions marketplace f... (!147718 - merged)

Description

As a Workspace Admin, I would like to configure a custom/private Extensions Marketplace for Engineers to use.

The initial minimal work to allow configuration via ENV vars is being tracked by Enable VS Code private extensions marketplace f... (#451941 - closed)

Acceptance Criteria

A breakdown of technical steps that allows us do this for Self-managed users is documented
Smaller issues on UX and Backend requirements related to the Settings module that allow us build this for Workspace Admins to do this themselves

Technical Requirements

The following requirement is copied from Add JSON support to Remote Dev Settings module (#452607 - closed):

proper structure of VS Code Extension Gallery settings override JSON when specified via an ENV var. E.g.:
- export GITLAB_REMOTE_DEVELOPMENT_VSCODE_EXTENSIONS_GALLERY='{"service_url":"https://marketplace.visualstudio.com/_apis/public/gallery","item_url":"https://marketplace.visualstudio.com/items","resource_url_template":"https://{publisher}.vscode-unpkg.net/{publisher}/{name}/{version}/{path}"}'
- RemoteDevelopment::Settings.get_single_setting(:vscode_extensions_gallery) should properly retrieve it.
- Misnamed/missing keys should raise an exception
- non-string values should raise an exception
The following variables must eventually be settable from the GITLAB_REMOTE_DEVELOPMENT_VSCODE_EXTENSIONS_GALLERY env var on the monolith: https://gitlab.com/gitlab-org/gitlab-web-ide-vscode-fork/-/blob/main/scripts/gl/tools-injector/gl_init_tools.sh?ref_type=heads#L28-L38
- GL_EDITOR_EXTENSIONS_GALLERY_SERVICE_URL
- GL_EDITOR_EXTENSIONS_GALLERY_ITEM_URL
- GL_EDITOR_EXTENSIONS_GALLERY_RESOURCE_URL_TEMPLATE
in ee/lib/remote_development/workspaces/create/workspace_variables.rb, add new entries for the GITLAB_REMOTE_DEVELOPMENT_VSCODE_EXTENSIONS_GALLERY var, and default the value as described above.
See https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/lib/remote_development/README.md#remote-development-settings for naming conventions of the ENV var (e.g. GITLAB_REMOTE_DEVELOPMENT_...)
Note that we are renaming EDITOR_EXTENSIONS* to VSCODE_EXTENSIONS_*, and can update this in the scripts/gl/tools-injector/gl_init_tools.sh file in the vscode fork.
Testing values for these come from (can't make this the default, because it's not a legal production use of the official VS Code extension gallery):

cat "/Applications/Visual Studio Code.app/Contents/Resources/app/product.json"

Search for ExtensionsGallery, e.g.:

	"extensionsGallery": {
		"nlsBaseUrl": "https://www.vscode-unpkg.net/_lp/",
		"serviceUrl": "https://marketplace.visualstudio.com/_apis/public/gallery",
		"cacheUrl": "https://vscode.blob.core.windows.net/gallery/index",
		"itemUrl": "https://marketplace.visualstudio.com/items",
		"publisherUrl": "https://marketplace.visualstudio.com/publishers",
		"resourceUrlTemplate": "https://{publisher}.vscode-unpkg.net/{publisher}/{name}/{version}/{path}",
		"controlUrl": "https://az764295.vo.msecnd.net/extensions/marketplace.json"
	},

Design Requirements

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Impact Assessment

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Edited Apr 10, 2024 by Chad Woolley