doc.go

/*
Package goproxy provides a customizable HTTP proxy,
supporting hijacking HTTPS connection.

The intent of the proxy, is to be usable with reasonable amount of traffic
yet, customizable and programable.

The proxy itself is simply an `net/http` handler.

Typical usage is

	proxy := goproxy.NewProxyHttpServer()
	proxy.OnRequest(..conditions..).Do(..requesthandler..)
	proxy.OnRequest(..conditions..).DoFunc(..requesthandlerFunction..)
	proxy.OnResponse(..conditions..).Do(..responesHandler..)
	proxy.OnResponse(..conditions..).DoFunc(..responesHandlerFunction..)
	http.ListenAndServe(":8080", proxy)

Adding a header to each request

	proxy.OnRequest().DoFunc(func(r *http.Request,ctx *goproxy.ProxyCtx) (*http.Request, *http.Response){
		r.Header.Set("X-GoProxy","1")
		return r, nil
	})

Note that the function is called before the proxy sends the request to the server

For printing the content type of all incoming responses

	proxy.OnResponse().DoFunc(func(r *http.Response, ctx *goproxy.ProxyCtx)*http.Response{
		println(ctx.Req.Host,"->",r.Header.Get("Content-Type"))
		return r
	})

note that we used the ProxyCtx context variable here. It contains the request
and the response (Req and Resp, Resp is nil if unavailable) of this specific client
interaction with the proxy.

To print the content type of all responses from a certain url, we'll add a
ReqCondition to the OnResponse function:

	proxy.OnResponse(goproxy.UrlIs("golang.org/pkg")).DoFunc(func(r *http.Response, ctx *goproxy.ProxyCtx)*http.Response{
		println(ctx.Req.Host,"->",r.Header.Get("Content-Type"))
		return r
	})

We can write the condition ourselves, conditions can be set on request and on response

	var random = ReqConditionFunc(func(r *http.Request) bool {
		return rand.Intn(1) == 0
	})
	var hasGoProxyHeader = RespConditionFunc(func(resp *http.Response,req *http.Request)bool {
		return resp.Header.Get("X-GoProxy") != ""
	})

Caution! If you give a RespCondition to the OnRequest function, you'll get a run time panic! It doesn't
make sense to read the response, if you still haven't got it!

Finally, we have convenience function to throw a quick response

	proxy.OnResponse(hasGoProxyHeader).DoFunc(func(r*http.Response,ctx *goproxy.ProxyCtx)*http.Response {
		r.Body.Close()
		return goproxy.ForbiddenTextResponse(ctx.Req,"Can't see response with X-GoProxy header!")
	})

we close the body of the original repsonse, and return a new 403 response with a short message.
*/
package goproxy