proxy-service.go

// Copyright 2022 The kubegems.io Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package apis

import (
	"fmt"
	"net/http"
	"net/http/httputil"
	"net/url"

	"github.com/gin-gonic/gin"
)

type ServiceProxyHandler struct{}

func (sp *ServiceProxyHandler) ServiceProxy(c *gin.Context) {
	var host string
	namespace := c.Request.Header.Get("namespace")
	service := c.Request.Header.Get("service")
	port := c.Request.Header.Get("port")

	if port == "" {
		host = fmt.Sprintf("%s.%s.svc", service, namespace)
	} else {
		host = fmt.Sprintf("%s.%s.svc:%s", service, namespace, port)
	}
	targetHost := url.URL{
		Host:   host,
		Scheme: "http",
	}
	realpath := c.Param("realpath")
	if realpath == "_" {
		realpath = ""
	}
	proxyInstance := httputil.NewSingleHostReverseProxy(&targetHost)
	proxyInstance.Director = func(req *http.Request) {
		req.Host = host
		req.URL.Host = host
		req.URL.Scheme = "http"
		req.URL.Path = "/" + realpath
		req.URL.RawQuery = c.Request.URL.Query().Encode()
	}
	proxyInstance.ServeHTTP(c.Writer, c.Request)
}