Support ISO InstallerType

[jantari]

Description of the new feature / enhancement

Similar to #182 where support for installers nested inside ZIP archives was added, support for installers nested inside ISO images is also required.

Some software, such as Veeam Backup and Replication Enterprise Suite or Microsoft Exchange Server is downloaded as .ISO files with Setup.exe or similar installers inside.

It should be easy for winget to mount or extract the ISO file just like a ZIP and access the nested installer(s).

Currently I would have to extract and recompress the entire 13GB ISO of the Veeam installer just so winget can handle it.

Proposed technical implementation details

Allow InstallerType: iso in the manifest schema and implement the support in the winget program and COM APIs.

[denelon]

I am not familiar with Veeam. WinGet would still need to download a 13GB ISO in that case correct? How big is the installer to be extracted? This seems like an excessive amount of bandwith if the installer inside an ISO is "small".

[jantari]

WinGet would still need to download a 13GB ISO in that case correct?

Correct, although I wouldn't concern myself with that number tbh. Veeam is licensed, proprietary "enterprise" software that can't be downloaded publicly. This particular installer would only be hosted by companies internally in private repositories.

How big is the installer to be extracted?

Since ISOs aren't really compressed, it's about 13GB.

Veeam is a Backup Suite, so looking into the ISO there's lots of split-off components (individual MSIs) in there that one may or may not use depending on what you need to back up (e.g. plugins for different cloud providers, different virtualization solutions, different databases etc.). Each of these is a few hundred MB. There's also "core" components that aren't optional and some redistributables (good ol' WebView2, .NET Core Runtime, VC++ Redist etc.) - the components make up the vast majority of the size, but it all adds up.

I guess they could've distributed those as individual downloads, but I can see how it's easier to set up this way: check/uncheck what you need rather than having to go hunt and peck for 10 separate downloads.

Anyway, Veeam just serves as an example here and the size of the archive/ISO isn't really the point. It's more about supporting nested installers inside an ISO file in general.

[pl4nty]

This sounds like part of #2899, particularly if tar.exe supports ISOs via LibArchive