Adding support for net/rpc over HTTPS

[Adam Thomason]

While net/rpc supports HTTPS trivially in the server, there's no built-in way for a client to connect to one since rpc.DialHTTPPath calls net.Dial itself. With some duplicated code from client.go it's possible to create a working DialHTTPSPath in user code, though this is suboptimal since DialHTTPPath references an unexported package variable which must be duplicated.

Would a patch to add DialHTTPSPath (and possibly DialHTTPS) be welcome?

http://play.golang.org/p/eYp3cke-Oj

// DialHTTPPath connects to an HTTP RPC server

// at the specified network address and path.

func DialHTTPPath(network, address, path string) (*Client, error) {

conn, err := net.Dial(network, address)

if err != nil {

return nil, err

}

return dialPath(network, address, path, conn)

}

// DialHTTPSPath connects to an HTTPS RPC server

// at the specified network address and path.

func DialHTTPSPath(network, address, path string, config *tls.Config) (*Client, error) {

conn, err := tls.Dial(network, address, config)

if err != nil {

return nil, err

}

return dialPath(network, address, path, conn)

}

func dialPath(network, address, path string, conn net.Conn) (*rpc.Client, error) {

io.WriteString(conn, "CONNECT "+path+" HTTP/1.0\n\n")

// Require successful HTTP response

// before switching to RPC protocol.

resp, err := http.ReadResponse(bufio.NewReader(conn), &http.Request{Method: "CONNECT"})

if err == nil && resp.Status == connected {

return NewClient(conn), nil

}

if err == nil {

err = errors.New("unexpected HTTP response: " + resp.Status)

}

conn.Close()

return nil, &net.OpError{

Op:   "dial-http",

Net:  network + " " + address,

Addr: nil,

Err:  err,

}

}

[Adam Thomason]

Since there were no objections, I've submitted this for review at https://codereview.appspot.com/100140043/.