38 lines
1022 B
Go
38 lines
1022 B
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"net/http"
|
|
"net/http/httputil"
|
|
"net/url"
|
|
)
|
|
|
|
func forwardRequest(
|
|
w http.ResponseWriter,
|
|
r *http.Request,
|
|
roundTripper http.RoundTripper,
|
|
fwdSvcURL *url.URL,
|
|
) {
|
|
proxy := httputil.NewSingleHostReverseProxy(fwdSvcURL)
|
|
proxy.Transport = roundTripper
|
|
proxy.Director = func(req *http.Request) {
|
|
req.URL = fwdSvcURL
|
|
req.Host = fwdSvcURL.Host
|
|
req.URL.Path = r.URL.Path
|
|
req.URL.RawQuery = r.URL.RawQuery
|
|
// delete the incoming X-Forwarded-For header so the proxy
|
|
// puts its own in. This is also important to prevent IP spoofing
|
|
req.Header.Del("X-Forwarded-For ")
|
|
}
|
|
proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
|
|
w.WriteHeader(502)
|
|
// note: we can only use the '%w' directive inside of fmt.Errorf,
|
|
// not Sprintf or anything similar. this means we have to create the
|
|
// failure string in this slightly convoluted way.
|
|
errMsg := fmt.Errorf("error on backend (%w)", err).Error()
|
|
w.Write([]byte(errMsg))
|
|
}
|
|
|
|
proxy.ServeHTTP(w, r)
|
|
}
|