examples:https-proxy:on a separate machine

[outprog]

i run ./http_proxy on machine A, output:

Proxy server is ready
libp2p-peer addresses:
/ip4/192.168.254.62/tcp/12000/ipfs/QmXBuLYVmDK2cKGLUnnku3TkJytQopeqip6SfUJzggjuyy

then, run

./http_proxy -d /ip4/192.168.254.62/tcp/12000/ipfs/QmXBuLYVmDK2cKGLUnnku3TkJytQopeqip6SfUJzggjuyy

on machine B, output:

Proxy server is ready
libp2p-peer addresses:
/ip4/127.0.0.1/tcp/12001/ipfs/QmNd9xzbysiAfqhavp1SYUPKiccvR4GiBqkfwANHEeQC8Q
proxy listening on  127.0.0.1:9900

now, type

curl -x "127.0.0.1:9900" "http://ipfs.io/ipfs/QmfUX75pGRBRDnjeoMkQzuQczuCup2aYbeLxz5NzeSu9G6"

on machine B, it's not work. output:

2017/11/27 11:45:45 dial attempt failed: <peer.ID Nd9xzb> --> <peer.ID XBuLYV> dial attempt failed: operation timed out

is this network problem? how can i fix it? thank u!

[Stebalien]

Probably. You'll have open tcp/12000 on machine A's firewall (and this will only work if those machines are on the same network as you're using private IP addresses).

[zqqq]

I have the same err,
After my test, not a firewall problem！

func makeRandomHost(port int) host.Host {
	priv, pub, err := crypto.GenerateKeyPair(crypto.RSA, 2048)
	if err != nil {
		log.Fatalln(err)
	}
	pid, err := peer.IDFromPublicKey(pub)
	if err != nil {
		log.Fatalln(err)
	}
	//	listen, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", port))
	//	if err != nil {
	//		log.Fatalln(err)
	//	}
	ps := ps.NewPeerstore()
	ps.AddPrivKey(pid, priv)
	ps.AddPubKey(pid, pub)

        //listen nil
	n, err := swarm.NewNetwork(context.Background(),
		nil, pid, ps, nil)
	if err != nil {
		log.Fatalln(err)
	}
	return bhost.New(n)
}

on makeRandomHost
Initialization, do not listen, such as initialization is completed, and then listen alone, so that you can connect successfully.

// If we have a destination peer we will start a local server
	if *destPeer != "" {
		// We use p2pport+1 in order to not collide if the user
		// is running the remote peer locally on that port
		host := makeRandomHost(*p2pport + 1)
		// Make sure our host knows how to reach destPeer
		destPeerID := addAddrToPeerstore(host, *destPeer)
		proxyAddr, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", *port))
		if err != nil {
			log.Fatalln(err)
		}
		// Create the proxy service and start the http server
		proxy := NewProxyService(host, proxyAddr, destPeerID)
		proxy.Serve() // serve hangs forever
	} else {
		host := makeRandomHost(*p2pport)
                //here is add
		addr, _ := ma.NewMultiaddr(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", *p2pport))
		err := host.Network().Listen(addr)
		if err != nil {
			panic(err)
		}

		// In this case we only need to make sure our host
		// knows how to handle incoming proxied requests from
		// another peer.
		_ = NewProxyService(host, nil, "")
		<-make(chan struct{}) // hang forever
	}

[outprog]

yes, it's not a firewall problem. First time, i just change proxy.go on remote peer(remote machine)

...
listen, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", port))
...
proxyAddr, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", *port))
...

to

...
listen, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/0.0.0.0/tcp/%d", port))
...
proxyAddr, err := ma.NewMultiaddr(fmt.Sprintf("/ip4/0.0.0.0/tcp/%d", *port))
...

use 0.0.0.0 can listen all ip. but it's not work.
last, i change proxy.go on both peer(remote machine and local machine), it's work. All machines use 0.0.0.0.

[Stebalien]

I see. Yeah, that's either a bug or something that should be documented clearly. It looks like you can't dial out of an interface you're not listening on.

[Stebalien]

Scratch that, it should still work (we have a fallback dialer).

[Stebalien]

Could you try changing only the listen address, not the proxy address, and see what happens?

[outprog]

@Stebalien
Yes, only the listen address, it's work. I think if want other meachine use peer's http proxy, then need change the proxy address.

[outprog]

By the same, ./example/echo, if we want to run it on a separate machine, must changing ip on both local and remote.

[Stebalien]

@whyrusleeping is this intended?

[whyrusleeping]

@Stebalien Its not necessarily intended. I just generally restrict demo applications to only listen on localhost