GoPackage-httputil

httputil

ReversrProxy

ReverseProxy 是一个http处理器，它接收一个请求，并将请求发送给其他服务器，代理响应到客户端。

type ReverseProxy struct {
        // Director must be a function which modifies
        // the request into a new request to be sent
        // using Transport. Its response is then copied
        // back to the original client unmodified.
        // Director must not access the provided Request
        // after returning.
        //Director是一个函数，它接收一个请求作为参数，
        //修改请求后发送给后端服务器
        //最后将接收到的请求原封不动的发送回客户端。
        Director func(*http.Request)

        // The transport used to perform proxy requests.
        // If nil, http.DefaultTransport is used.
        //用于执行代理请求
        Transport http.RoundTripper

        // FlushInterval specifies the flush interval
        // to flush to the client while copying the
        // response body.
        // If zero, no periodic flushing is done.
        // A negative value means to flush immediately
        // after each write to the client.
        // The FlushInterval is ignored when ReverseProxy
        // recognizes a response as a streaming response;
        // for such responses, writes are flushed to the client
        // immediately.
        FlushInterval time.Duration

        // ErrorLog specifies an optional logger for errors
        // that occur when attempting to proxy the request.
        // If nil, logging goes to os.Stderr via the log package's
        // standard logger.
        ErrorLog *log.Logger // Go 1.4

        // BufferPool optionally specifies a buffer pool to
        // get byte slices for use by io.CopyBuffer when
        // copying HTTP response bodies.
        BufferPool BufferPool // Go 1.6

        // ModifyResponse is an optional function that modifies the
        // Response from the backend. It is called if the backend
        // returns a response at all, with any HTTP status code.
        // If the backend is unreachable, the optional ErrorHandler is
        // called without any call to ModifyResponse.
        //
        // If ModifyResponse returns an error, ErrorHandler is called
        // with its error value. If ErrorHandler is nil, its default
        // implementation is used.
        ModifyResponse func(*http.Response) error // Go 1.8

        // ErrorHandler is an optional function that handles errors
        // reaching the backend or errors from ModifyResponse.
        //
        // If nil, the default is to log the provided error and return
        // a 502 Status Bad Gateway response.
        ErrorHandler func(http.ResponseWriter, *http.Request, error) // Go 1.11
}