Resolving links in sharded directories does not seem to work

[victorb]

Version information:

Gateways running commit 1dede1b

Type:

Bug

Description:

I've tried three projects that are using sharded directories and one without. The one without resolves links correctly but none of the projects using sharded directories works for resolving links. However, it does work when using 0.4.15

• https://localhost:7002/ipns/arch.victor.earth/community works correctly (using version 0.4.15)
• https://ipfs.io/ipns/arch.victor.earth/community gets error message ipfs resolve -r /ipns/arch.victor.earth/community: no link by that name

[magik6k]

Likely introduced in #4672 which switched from using path.pesolver.ResolvePath to path.pesolver.ResolveToLastNode which doesn't appear to respect Resolver.ResolveOnce. As the gateway uses coreapi it got affected by this

[victorb]

@magik6k something is still weird here...

https://ipfs.io/ipfs/QmXeh5S5Dk528ueFX3iFRB5TuKUNrWM9dEiLfC4crVwuHD is a sharded directory.

https://ipfs.io/ipfs/QmXeh5S5Dk528ueFX3iFRB5TuKUNrWM9dEiLfC4crVwuHD/PAL_Express.html gives me no link by that name

If I look on the IPLD explorer and take that path: https://explore.ipld.io/#/explore/QmXeh5S5Dk528ueFX3iFRB5TuKUNrWM9dEiLfC4crVwuHD it would be 27PAL_Express.html

https://ipfs.io/ipfs/QmXeh5S5Dk528ueFX3iFRB5TuKUNrWM9dEiLfC4crVwuHD/27PAL_Express.html gives me inconsistent ResolveOnce / nd.Resolve

[victorb]

Also:

$ ipfs resolve /ipfs/QmXeh5S5Dk528ueFX3iFRB5TuKUNrWM9dEiLfC4crVwuHD/PAL_Express.html
Error: no link named "PAL_Express.html" under QmXeh5S5Dk528ueFX3iFRB5TuKUNrWM9dEiLfC4crVwuHD

[magik6k]

Looking at it

[magik6k]

So that's probably a separate issue as the right resolver is used, and on the right nodes. The error seems to come from https://github.com/ipfs/go-unixfs/blob/master/hamt/hamt.go#L388. Digging deeper

[magik6k]

I tried this on v0.4.[10,16,17] and master, none of them worked so it's either broken hamt or an older regression. How did you get that hash?

[whyrusleeping]

It would be interesting to figure out what exactly is malformed here, and how @victorbjelkholm managed to get an incorrectly formed sharded directory.

Also better error messages would be 🔥

[victorb]

I'm not sure where those hashes come from, don't remember. But here is another example from Cloudflares Stack Exchange archive:

https://ipfs.io/ipfs/QmVsEiBRsdiHMvmDVJTNtrXNqSKYdtoepcoZxUrQ8rU7qR/ham/A/index.html

There is supposed to be a directory called /ham under QmVsEiBRsdiHMvmDVJTNtrXNqSKYdtoepcoZxUrQ8rU7qR but the following happens instead:

$ ipfs resolve /ipfs/QmVsEiBRsdiHMvmDVJTNtrXNqSKYdtoepcoZxUrQ8rU7qR/ham
Error: no link named "ham" under QmVsEiBRsdiHMvmDVJTNtrXNqSKYdtoepcoZxUrQ8rU7qR

[magik6k]

I'll look into this later today

[victorb]

Thanks @magik6k

IPLD explorer to the rescue! Loaded it up (https://explore.ipld.io/#/explore/QmVsEiBRsdiHMvmDVJTNtrXNqSKYdtoepcoZxUrQ8rU7qR) and found the "true" directory name 05ham which actually resolves this time:

$ ipfs resolve /ipfs/QmVsEiBRsdiHMvmDVJTNtrXNqSKYdtoepcoZxUrQ8rU7qR/05ham
/ipfs/zdj7WZpLoZYr4AoDUdpCNBVHLi1S8y6muFoCgwUa9kmxUpYCr

So it's not fully "not-working" :)

[victorb]

Thanks @Stebalien and @magik6k, I can confirm that the resolve now works for sharded directories!