github.com/cuiweixie/go-ethereum@v1.8.2-0.20180303084001-66cd41af1e38/swarm/api/http/roundtripper.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package http
    18  
    19  import (
    20  	"fmt"
    21  	"net/http"
    22  
    23  	"github.com/ethereum/go-ethereum/log"
    24  )
    25  
    26  /*
    27  http roundtripper to register for bzz url scheme
    28  see https://github.com/ethereum/go-ethereum/issues/2040
    29  Usage:
    30  
    31  import (
    32   "github.com/ethereum/go-ethereum/common/httpclient"
    33   "github.com/ethereum/go-ethereum/swarm/api/http"
    34  )
    35  client := httpclient.New()
    36  // for (private) swarm proxy running locally
    37  client.RegisterScheme("bzz", &http.RoundTripper{Port: port})
    38  client.RegisterScheme("bzz-immutable", &http.RoundTripper{Port: port})
    39  client.RegisterScheme("bzz-raw", &http.RoundTripper{Port: port})
    40  
    41  The port you give the Roundtripper is the port the swarm proxy is listening on.
    42  If Host is left empty, localhost is assumed.
    43  
    44  Using a public gateway, the above few lines gives you the leanest
    45  bzz-scheme aware read-only http client. You really only ever need this
    46  if you need go-native swarm access to bzz addresses.
    47  */
    48  
    49  type RoundTripper struct {
    50  	Host string
    51  	Port string
    52  }
    53  
    54  func (self *RoundTripper) RoundTrip(req *http.Request) (resp *http.Response, err error) {
    55  	host := self.Host
    56  	if len(host) == 0 {
    57  		host = "localhost"
    58  	}
    59  	url := fmt.Sprintf("http://%s:%s/%s:/%s/%s", host, self.Port, req.Proto, req.URL.Host, req.URL.Path)
    60  	log.Info(fmt.Sprintf("roundtripper: proxying request '%s' to '%s'", req.RequestURI, url))
    61  	reqProxy, err := http.NewRequest(req.Method, url, req.Body)
    62  	if err != nil {
    63  		return nil, err
    64  	}
    65  	return http.DefaultClient.Do(reqProxy)
    66  }