zrok/endpoints/proxyBackend/http.go
2023-01-04 14:42:58 -05:00

101 lines
2.2 KiB
Go

package proxyBackend
import (
"context"
"github.com/openziti-test-kitchen/zrok/util"
"github.com/openziti/sdk-golang/ziti"
"github.com/openziti/sdk-golang/ziti/config"
"github.com/openziti/sdk-golang/ziti/edge"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"net"
"net/http"
"net/http/httputil"
"net/url"
"time"
)
type Config struct {
IdentityPath string
EndpointAddress string
ShrToken string
}
type backend struct {
cfg *Config
requests func() int32
listener edge.Listener
handler http.Handler
}
func NewBackend(cfg *Config) (*backend, error) {
options := ziti.ListenOptions{
ConnectTimeout: 5 * time.Minute,
MaxConnections: 64,
}
zcfg, err := config.NewFromFile(cfg.IdentityPath)
if err != nil {
return nil, errors.Wrap(err, "error loading config")
}
listener, err := ziti.NewContextWithConfig(zcfg).ListenWithOptions(cfg.ShrToken, &options)
if err != nil {
return nil, errors.Wrap(err, "error listening")
}
proxy, err := newReverseProxy(cfg.EndpointAddress)
if err != nil {
return nil, err
}
handler := util.NewProxyHandler(proxy)
return &backend{
cfg: cfg,
requests: handler.Requests,
listener: listener,
handler: handler,
}, nil
}
func (self *backend) Run() error {
if err := http.Serve(self.listener, self.handler); err != nil {
return err
}
return nil
}
func (self *backend) Requests() func() int32 {
return self.requests
}
func newReverseProxy(target string) (*httputil.ReverseProxy, error) {
targetURL, err := url.Parse(target)
if err != nil {
return nil, err
}
tpt := http.DefaultTransport.(*http.Transport).Clone()
tpt.DialContext = metricsDial
proxy := httputil.NewSingleHostReverseProxy(targetURL)
proxy.Transport = tpt
director := proxy.Director
proxy.Director = func(req *http.Request) {
director(req)
logrus.Debugf("-> %v", req.URL.String())
req.Header.Set("X-Proxy", "zrok")
}
proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
logrus.Errorf("error proxying: %v", err)
}
return proxy, nil
}
func metricsDial(_ context.Context, network string, addr string) (net.Conn, error) {
conn, err := net.Dial(network, addr)
if err != nil {
return conn, err
}
return newMetricsConn("backend", conn), nil
}