unix-friendly output for 'ipfs dht' commands

[hackergrrl]

Work Items

• [x] ipfs dht findprovs: lists the full peerIDs of providers, one per line (https://github.com/ipfs/go-ipfs/pull/2560)
• [x] ipfs dht findpeer: lists multiaddrs discovered for the given peer, one per line (https://github.com/ipfs/go-ipfs/pull/2560)
• [x] ipfs dht get: outputs the single best value selected for that key (https://github.com/ipfs/go-ipfs/pull/2560)
• [x] ipfs dht query: lists of closest peer IDs, one per line (https://github.com/ipfs/go-ipfs/pull/2560)
• [x] ipfs dht put: lists the peer IDs of the peers that it stored a record with (https://github.com/ipfs/go-ipfs/pull/2560)
• [x] more clearly document the helptext across all commands (https://github.com/ipfs/go-ipfs/pull/2560)
• [ ] output all verbose output to stderr
• [ ] provide a flag for 'ifps dht get' that lists all records (not just the best one)

  Summary

Today:

$ ipfs dht findprovs QmNmL1foPtvw25dWR41eeqW5YcLZJA5b3XoKrrBYUwKhnv
QmRc5iJERYKMjFsJ57jsxJhUjf86HL1WyqrQBTJrCCAnKN
* <peer.ID QmT3B2> says use <peer.ID QmPhm1> <peer.ID QmaL57> <peer.ID QmRv1G> <peer.ID QmYHk2> <peer.ID QmSoLn> <peer.ID QmXSyB> <peer.ID QmZyo1> <peer.ID QmRPhq> <peer.ID QmV7E3> <peer.ID QmNMeh> 
* <peer.ID QmRv1G> says use <peer.ID QmPhm1> <peer.ID QmaL57> <peer.ID QmT3B2> <peer.ID QmSNEN> <peer.ID QmYHk2> <peer.ID QmSoLn> <peer.ID QmXSyB> <peer.ID QmZyo1> <peer.ID QmUZax> <peer.ID QmRPhq> <peer.ID QmV7E3> <peer.ID QmNMeh> <peer.ID QmUDHg> <peer.ID QmSoLj> <peer.ID Qmda2A> <peer.ID QmVhJf> <peer.ID QmfBPE> <peer.ID QmZY7M> <peer.ID QmR5Cr> <peer.ID QmaSfi>

Imagined output:

$ ipfs dht findprovs QmNmL1foPtvw25dWR41eeqW5YcLZJA5b3XoKrrBYUwKhnv
QmNh2nZ3tWc8hbAbGNmfQQN9TmPAkpwKztjH8xZvcrv3eF
QmSoLju6m7xTh3DuokvT3886QRYqxAzb1kShaanJgW36yx
QmSoLnSGccFuZQJzRadHn95W2CrSFmZuTdDWP8HXaHca9z
...

Important properties:

1. no errors inlined into output (or, use stderr at least)
2. simple, newline-delimited output that is immediately usable for unix programs

This makes the commands much friendlier to unix scripts -- IDs can be grabbed and fed into e.g. ipfs dht findpeer more or less directly! We could still retain a -s|--simple option that gives short PeerIDs for existing compatibility, and keep -v|--verbose for detailed human output.

---

cc @whyrusleeping

[whyrusleeping]

Heres what I would like to see as output for the various subcommands of ipfs dht

• ipfs dht findprovs
  • defaults to listing full peerIDs of providers, one per line
• ipfs dht findpeer
  • defaults to just listing multiaddrs discovered for the given peer, one per line
• ipfs dht get
  • defaults to just outputting the single best value selected for that key
  • an option to output every received value (including duplicates and bad values) is very much wanted
• ipfs dht query
  • list of peer ID's, one per line by default

And for each of those, a verbose flag that prints the dht debugging events as they come in, making sure there arent any missed event types.

[hackergrrl]

What format would you like to see for a PeerID?

• QmRc5iJERYKMjFsJ57jsxJhUjf86HL1WyqrQBTJrCCAnKN
• /ipfs/QmRc5iJERYKMjFsJ57jsxJhUjf86HL1WyqrQBTJrCCAnKN
• /ip6/2601:646:8500:1f00:7256:81ff:feb1:c7bd/tcp/4001/ipfs/QmRc5iJERYKMjFsJ57jsxJhUjf86HL1WyqrQBTJrCCAnKN
• something else!

[whyrusleeping]

peer IDs are just the Qm... hash

[hackergrrl]

One more: how about ipfs dht put?

[whyrusleeping]

ehm... i guess it should take input from a file or standard in, and print out the peer IDs of peers that it stored a record with

[hackergrrl]

I've tackled most of these with https://github.com/ipfs/go-ipfs/pull/2560, but two trickier pieces remain:

verbose output to stderr

Since all output comes from the daemon over a single channel, we'll need to wrap its output in a struct or similar so it can be multiplexed to (stdout, stderr) on the receiving end.

flag to list all records on ipfs dht get

Records are generally binary, so newline delimited output doesn't work here. We'll need to figure out how we'd like to format this output (newline'd base64? JSON?) to be maximally useful for users of this feature.