Content routing hint via HTTP headers

[Stebalien]

Came up in #6383 (comment).

The HTTP gateway could read a (series of) IPFS-Provider: /some/multiaddr hint(s) and use them to inform content routing decisions when trying to find the content in question.

This could be useful for (d)apps that have known stable providers. IPFS would/could still look elsewhere, this would just allow dapps to provide a known-good fallback.

[jasonzhouu]

That's a really good feature, I think.
But I have a puzzle about the github issue label of "help wanted". Does it mean IPFS needs some help from the community to realize this feature?

[lanzafame]

@jasonzhouu It means that we would love for the community to contribute the feature and are open to it being contributed by the community.

[lidel]

Dapps and IPFS Companion can add HTTP Header, but regular people will copy & paste links.
Something to consider is to support both HTTP header and a hint in URL (see Proposal: Peer Hint URI scheme). To avoid clutter in address bar, hint in URL could be removed via 302 redirect.

[howjmay]

I would like to take this issue, but I wonder how could I hint the content routing decision?

[Stebalien]

The ideal solution would be to add content routing hints to the context, then extract them inside bitswap.

However, at the moment, the entire team is heads-down trying to pull together the final changes for the go-ipfs 0.5.0 release (#6776), slated for the end of the month, and will have very limited time to review/design changes like this. Would you mind coming back and asking again in about a month (second week of April)?

[hsanjuan]

I removed the Help Wanted label as it seems this needs a solid design proposal (or a set of them) taking into account the discussions linked above: will it be headers? url hints? both? how will they be named? what formats are accepted for the hint? full multiaddress? just a peer id? how does this play with the idea of having magnet-links or even ipfs torrent-files?.

Closing this design or as least some actionable parts of it would be a good milestone post 0.5.0 and I think it will be a priority along further improvements to content resolution. It the meantime we continue hearing ideas and design proposals.

[dokterbob]

This would be super beneficial for us at ipfs-search.com. We are getting All the Provider Records, but still somehow, our go-ipfs node seems to have trouble finding resources.

[bertrandfalguiere]

Another design would be to use the Alt-svc HTTP header like in Tor Browser, and possibly Brave:
ipfs/in-web-browsers#144