go-proxy/options.go

package proxy

import (
	"context"
	"net/http"
	"net/http/httputil"
	"net/url"
)

type Options struct {
	Middlewares          []Middleware
	RequestTransformers  []RequestTransformer
	ResponseTransformers []ResponseTransformer
	ReverseProxyFactory  ReverseProxyFactory
	DefaultHandler       http.Handler
}

func defaultOptions() *Options {
	return &Options{
		Middlewares:          make([]Middleware, 0),
		RequestTransformers:  make([]RequestTransformer, 0),
		ResponseTransformers: make([]ResponseTransformer, 0),
		ReverseProxyFactory:  DefaultReverseProxyFactory,
		DefaultHandler:       DefaultHandler,
	}
}

type OptionFunc func(*Options)

func WithMiddlewares(middlewares ...Middleware) OptionFunc {
	return func(o *Options) {
		o.Middlewares = middlewares
	}
}

func WithRequestTransformers(transformers ...RequestTransformer) OptionFunc {
	return func(o *Options) {
		o.RequestTransformers = transformers
	}
}

func WithResponseTransformers(transformers ...ResponseTransformer) OptionFunc {
	return func(o *Options) {
		o.ResponseTransformers = transformers
	}
}

type ReverseProxyFactory func(ctx context.Context, target *url.URL) *httputil.ReverseProxy

func WithReverseProxyFactory(fn ReverseProxyFactory) OptionFunc {
	return func(o *Options) {
		o.ReverseProxyFactory = fn
	}
}

func DefaultReverseProxyFactory(ctx context.Context, target *url.URL) *httputil.ReverseProxy {
	return httputil.NewSingleHostReverseProxy(target)
}

func WithDefaultHandler(handler http.Handler) OptionFunc {
	return func(o *Options) {
		o.DefaultHandler = handler
	}
}

var DefaultHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	http.Error(w, http.StatusText(http.StatusBadGateway), http.StatusBadGateway)
})