Routing: conform DHT to common Router interface

[ajnavarro]

Description

Delegated routing implementation (#8997) currently only supports reframe routers. Implement DHT routers so they can be added as a new type on delegated routing config list. Actual DHT config initialization and behavior must work as before.

New design document here: https://hackmd.io/@ajnavarro/HJr059wC9

• Config documentation: Add a new routing type and explain different possible parameters
• Tests: add new tests on delegatred_test.go
• Deprecate any old configuration param used to create the DHT (previous, simpler configuration will not be deprecated)
• Support any DHT kind that is already supported today (including experimental DHT clients)
• Use special routers to support the different router behaviors (New Routing helpers: parallel and sequential. libp2p/go-libp2p-routing-helpers#56)

[BigLep]

@ajnavarro : Is this really about "delegated routing", or about having all our routing options (ipfs/go-delegated-routing and libp2p/go-libp2p-kad-dht) conforming to common pattern/interface?

[ajnavarro]

It's the latter, having all our routing options conforming to a common pattern.

[ajnavarro]

Example of delegated routing configuration with DHT router:

{
  "Type": "reframe",
  "Enabled": true,
  "Parameters": {
    "Endpoint": "https://cid.contact/reframe",
    "Priority": 100
  }
},
{
  "Type": "dht",
  "Enabled": true,
  "Parameters": {
    "Priority": 200,
    "DHTMode": "dhtclient", # It can also be "dht", "dhtserver" and "none" too. "dht" by default.
    "TrackFullNetwork": false, # experimental dht
    "Concurrency": 10 # we can expose internal configuration params to tweak DHTs.
    "Prefix": "/ipfs" # shall we expose used prefix?
  }
}

[ajnavarro]

I'm having some problems refactoring how DHT is created on Kubo. The main DHT Router is created at the same time than Host here:

kubo/core/node/libp2p/host.go

Lines 56 to 65 in 7ec0c24

	opts = append(opts, libp2p.Routing(func(h host.Host) (routing.PeerRouting, error) {
	r, err := params.RoutingOption(
	ctx, h,
	params.Repo.Datastore(),
	params.Validator,
	bootstrappers...,
	)
	out.Routing = r
	return r, err
	}))

It uses RoutingOption and a list of libp2p.Option.

• libp2p.Option are obtained from here: https://github.com/ipfs/kubo/blob/master/core/node/libp2p/libp2p.go
• RoutingOption is obtained from builder.go:
  

  kubo/core/node/builder.go

  Lines 108 to 110 in 7ec0c24

  	routingOption := fx.Provide(func() libp2p.RoutingOption {
  	return cfg.Routing
  	})

I feel that everything is more complicated than it should be, so I'm tempted to refactor all DHT-related code to make it easier to update in the future. Maybe we don't want to spend time on this, so @lidel @guseggert @aschmahmann @Jorropo I would love to have some feedback about the following possible solutions:

1. Refactor all code related to RoutingOption to make it simpler. The previous DHT configuration will still work as before. New DHT routers created by the new configuration will use global libp2p.Options like ForceReachability and ConnectionManager
2. Leave the main DHT as it is. Make it possible to add more DHT Routers apart from the main DHT. AFAIK the only part that is making direct use of the DHT is AutoRelayFeeder. We can add a configuration flag that will make that DHT to be used on AutoRelayFeeder if needed.
3. Other proposed solutions.

WDYT?

[ajnavarro]

As we discussed, I will make a comparison between config files before, and after the change (I'll remove the irrelevant parts to have less noise):

Before:

Config file

{
  "Identity": {
    [...]
  },
  "Datastore": {
    [...]
  },
  "Addresses": {
    "Swarm": [
      "/ip4/0.0.0.0/tcp/4001",
      "/ip6/::/tcp/4001",
      "/ip4/0.0.0.0/udp/4001/quic",
      "/ip6/::/udp/4001/quic"
    ],
    "Announce": [],
    "AppendAnnounce": [],
    "NoAnnounce": [],
    "API": "/ip4/127.0.0.1/tcp/5001",
    "Gateway": "/ip4/127.0.0.1/tcp/8080"
  },
  "Discovery": {
    "MDNS": {
      "Enabled": true
    }
  },
  "Routing": {
    "Type": "dht",
    "Routers": {}
  },
  "Bootstrap": [
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN",
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmQCU2EcMqAqQPR2i9bChDtGNJchTbq5TbXJJ16u19uLTa",
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb",
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt",
    "/ip4/104.131.131.82/tcp/4001/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ",
    "/ip4/104.131.131.82/udp/4001/quic/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ"
  ],
  "Gateway": {
    [...]
  },
  "API": {
    "HTTPHeaders": {}
  },
  "Swarm": {
    "AddrFilters": null,
    "DisableBandwidthMetrics": false,
    "DisableNatPortMap": false,
    "RelayClient": {},
    "RelayService": {},
    "Transports": {
      "Network": {},
      "Security": {},
      "Multiplexers": {}
    },
    "ConnMgr": {
      "Type": "basic",
      "LowWater": 600,
      "HighWater": 900,
      "GracePeriod": "20s"
    },
    "ResourceMgr": {}
  },
  "AutoNAT": {},
  "Pubsub": {
    "Router": "",
    "DisableSigning": false
  },
  "Peering": {
    "Peers": null
  },
  "DNS": {
    "Resolvers": {}
  },
  "Migration": {
    [...]
  },
  "Provider": {
    "Strategy": ""
  },
  "Reprovider": {
    [...]
  },
  "Experimental": {
    [...]
    "AcceleratedDHTClient": false
  },
  "Plugins": {
    [...]
  },
  "Pinning": {
    [...]
  },
  "Internal": {}
}

• Bootstrap is generic for all DHTs
• Routing.Type is where dht is specified.
• AcceleratedDHTClient is on Experimental flags.

After:

Config file

{
  "Identity": {
    [...]
  },
  "Datastore": {
    [...]
  },
  "Addresses": {
    "Swarm": [
      "/ip4/0.0.0.0/tcp/4001",
      "/ip6/::/tcp/4001",
      "/ip4/0.0.0.0/udp/4001/quic",
      "/ip6/::/udp/4001/quic"
    ],
    "Announce": [],
    "AppendAnnounce": [],
    "NoAnnounce": [],
    "API": "/ip4/127.0.0.1/tcp/5001",
    "Gateway": "/ip4/127.0.0.1/tcp/8080"
  },
  "Discovery": {
    "MDNS": {
      "Enabled": true
    }
  },
  "Routing": {
    "Routers": {
	 "storetheindex": {
	    "Type": "reframe",
	    "Enabled": true,
	    "Parameters": {
	      "Endpoint": "https://cid.contact/reframe",
	      "Priority": 100
	    }
	  },
	 "ipfs-public-dht" : {
	 	"Type" : "dht"
		"Enabled" : "true"
		"Methods" : ["put-ipns", "get-p2p-providers", ...]
		"Parameters" : {
			"Mode" : "auto"
			"TrackFullNetworkDHT": true,
			"ProtocolID" : "/ipfs/kad/1.0.0"
			"Bootstrappers" : [
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN",
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmQCU2EcMqAqQPR2i9bChDtGNJchTbq5TbXJJ16u19uLTa",
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb",
    "/dnsaddr/bootstrap.libp2p.io/p2p/QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt",
    "/ip4/104.131.131.82/tcp/4001/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ",
    "/ip4/104.131.131.82/udp/4001/quic/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ"
  ]
				"Public-IP-Network" : "true"
				}
		}
		"ipfs-lan-dht" : {
				"Type" : "dht"
				"Enabled" : "false"
				"Methods" : ["put-ipns", "get-p2p-providers", ...]
				"Parameters" : {
					"Mode" : "server"
					"ProtocolID" : "/ipfs/lan/kad/1.0.0"
					"Bootstrappers" : []
					"Public-IP-Network" : "false"
				}
		}
	}
  },
  "Gateway": {
    [...]
  },
  "API": {
    "HTTPHeaders": {}
  },
  "Swarm": {
    "AddrFilters": null,
    "DisableBandwidthMetrics": false,
    "DisableNatPortMap": false,
    "RelayClient": {},
    "RelayService": {},
    "Transports": {
      "Network": {},
      "Security": {},
      "Multiplexers": {}
    },
    "ConnMgr": {
      "Type": "basic",
      "LowWater": 600,
      "HighWater": 900,
      "GracePeriod": "20s"
    },
    "ResourceMgr": {}
  },
  "AutoNAT": {},
  "Pubsub": {
    "Router": "",
    "DisableSigning": false
  },
  "Peering": {
    "Peers": null
  },
  "DNS": {
    "Resolvers": {}
  },
  "Migration": {
    [...]
  },
  "Provider": {
    "Strategy": ""
  },
  "Reprovider": {
    [...]
  },
  "Experimental": {
    [...]
  },
  "Plugins": {
    [...]
  },
  "Pinning": {
    [...]
  },
  "Internal": {}
}

• Global Bootstrap config param disappear.
• Routing.Type is removed.
• AcceleratedDHTClient is replaced by TrackFullNetworkDHT

Steps:

• Refactor how DHT is created and how it interacts with other modules to make it possible to create several ones.
• Add a new default config that works as before, adding the WAN and LAN DHTs on Routers config.
• Add tests for everything (wrong config params validation, new default config === old default config...)
  (2 days - getting tests to pass)
• Create a migration. I need to familiarize with migrations repo
• Test migration
  (challenge here is that need to make sure don't screw anything u. Really need to scrutinize for corner cases. Not so bad here because we're doing config file migration. 1 week)
  (we have other stuff we want to include in migration code)