This example shows how to create a simple HTTP proxy service with libp2p:
XXX
XX XXXXXX
X XX
XXXXXXX XX XX XXXXXXXXXX
+----------------+ +-----------------+ XXX XXX XXX XXX
HTTP Request | | | | XX XX
+-----------------> | libp2p stream | | HTTP X X
| Local peer <----------------> Remote peer <-------------> HTTP SERVER - THE INTERNET XX
<-----------------+ | | | Req & Resp XX X
HTTP Response | libp2p host | | libp2p host | XXXX XXXX XXXXXXXXXXXXXXXXXXXX XXXX
+----------------+ +-----------------+ XXXXX
In order to proxy an HTTP request, we create a local peer which listens on localhost:9900. HTTP requests performed to that address are tunneled via a libp2p stream to a remote peer, which then performs the HTTP requests and sends the response back to the local peer, which relays it to the user.
Note that this is a very simple approach to a proxy, and does not perform any header management, nor supports HTTPS. The proxy.go code is thoroughly commented, detailing what is happening in every step.
From the go-libp2p/examples directory run the following:
> cd http-proxy/
> go build
First run the "remote" peer as follows. It will print a local peer address. If you would like to run this on a separate machine, please replace the IP accordingly:
> ./http-proxy
Proxy server is ready
libp2p-peer addresses:
/ip4/127.0.0.1/tcp/12000/p2p/QmddTrQXhA9AkCpXPTkcY7e22NK73TwkUms3a44DhTKJTDThen run the local peer, indicating that it will need to forward http requests to the remote peer as follows:
> ./http-proxy -d /ip4/127.0.0.1/tcp/12000/p2p/QmddTrQXhA9AkCpXPTkcY7e22NK73TwkUms3a44DhTKJTD
Proxy server is ready
libp2p-peer addresses:
/ip4/127.0.0.1/tcp/12001/p2p/Qmaa2AYTha1UqcFVX97p9R1UP7vbzDLY7bqWsZw1135QvN
proxy listening on 127.0.0.1:9900
As you can see, the proxy prints the listening address 127.0.0.1:9900. You can now use this address as a proxy, for example with curl:
> curl -x "127.0.0.1:9900" "http://ipfs.io/p2p/QmfUX75pGRBRDnjeoMkQzuQczuCup2aYbeLxz5NzeSu9G6"
it works!