add tarfile/zipfile downloads to HTTP gateway

[DeedleFake]

I have a number of things that I have backed up to an IPFS cluster that I'm running. I'd like to be able to download an entire directory as an archive of some kind, either a tarball or a zipfile, through the gateway, but there doesn't seem to be a way to do this. I looks around for a while, but was unable to find anything about downloading directories in any way via the gateway, other than one file at a time.

Would it be possible for the gateway to get the ability to add a query parameter, like ?format=zip or something, that, when given on a directory path, results in a zipfile containing the contents of the directory instead of the usual UI?

If this makes sense, a link being added to the gateway's directory UI to download the current directory would be a nice corollary.

[Stebalien]

You can use the read-only API: https://your-gateway/api/v0/get?arg=/the/path/you/want`. That will give you a .tar file (with the incorrect content type, apparently...).

But I agree making this a gateway feature and linking to it from the directory index would be really nice.

[lidel]

Support for ?download=tar|tgz|tar.gz (ipfs get) could be easy to wire up, and I believe we could do that while we add support for ?download=car (ipfs dag export), as suggested in ipfs/in-web-browsers#170 (something I'd like to help with personally).

[obo20]

we've had a few customers ask for this recently. This would be a nice functionality to provide if possible.

[RubenKelevra]

@Stebalien / @lidel can we just add a download button to the directory listings, to download the current view from the current gateway? This would make it MUCH easier for the users.

[lidel]

CAR

With ?format=car added in #8758 it should be now possible to edit /assets/dir-index-html/src/dir-index.html to add "Download CAR" button that exports current dir index as CAR – if anyone has time to PR, ping me for review 👍

TAR

Doing something similar for TAR is also welcome, but should be a separate PR from CAR (CAR and TAR serve different purposes) and since it is a new behavior, the proposal should come with specs first.

Update: see #9029