zrok/endpoints/proxy/backend.go
2024-09-10 13:46:17 -04:00

107 lines
2.4 KiB
Go

package proxy
import (
"crypto/tls"
"fmt"
"github.com/openziti/sdk-golang/ziti"
"github.com/openziti/sdk-golang/ziti/edge"
"github.com/openziti/zrok/endpoints"
"github.com/openziti/zrok/util"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"net/http"
"net/http/httputil"
"net/url"
"time"
)
type BackendConfig struct {
IdentityPath string
EndpointAddress string
ShrToken string
Insecure bool
Requests chan *endpoints.Request
}
type Backend struct {
cfg *BackendConfig
listener edge.Listener
handler http.Handler
}
func NewBackend(cfg *BackendConfig) (*Backend, error) {
options := ziti.ListenOptions{
ConnectTimeout: 5 * time.Minute,
WaitForNEstablishedListeners: 1,
}
zcfg, err := ziti.NewConfigFromFile(cfg.IdentityPath)
if err != nil {
return nil, errors.Wrap(err, "error loading config")
}
zctx, err := ziti.NewContext(zcfg)
if err != nil {
return nil, errors.Wrap(err, "error loading ziti context")
}
listener, err := zctx.ListenWithOptions(cfg.ShrToken, &options)
if err != nil {
return nil, errors.Wrap(err, "error listening")
}
proxy, err := newReverseProxy(cfg)
if err != nil {
return nil, err
}
handler := util.NewRequestsWrapper(proxy)
return &Backend{
cfg: cfg,
listener: listener,
handler: handler,
}, nil
}
func (b *Backend) Run() error {
if err := http.Serve(b.listener, b.handler); err != nil {
return err
}
return nil
}
func (b *Backend) Stop() error {
return b.listener.Close()
}
func newReverseProxy(cfg *BackendConfig) (*httputil.ReverseProxy, error) {
targetURL, err := url.Parse(cfg.EndpointAddress)
if err != nil {
return nil, err
}
tpt := http.DefaultTransport.(*http.Transport).Clone()
if cfg.Insecure {
tpt.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
}
proxy := httputil.NewSingleHostReverseProxy(targetURL)
proxy.Transport = tpt
director := proxy.Director
proxy.Director = func(req *http.Request) {
if cfg.Requests != nil {
cfg.Requests <- &endpoints.Request{
Stamp: time.Now(),
RemoteAddr: fmt.Sprintf("%v", req.Header["X-Real-Ip"]),
Method: req.Method,
Path: req.URL.String(),
}
}
director(req)
req.Header.Set("X-Proxy", "zrok")
}
proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
logrus.Errorf("error proxying: %v", err)
w.WriteHeader(http.StatusBadGateway)
}
return proxy, nil
}