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package kubernetes
import (
"fmt"
"io"
"log"
"net"
"net/http"
"github.com/coredns/coredns/middleware/pkg/healthcheck"
)
type proxyHandler struct {
healthcheck.HealthCheck
}
type apiProxy struct {
http.Server
listener net.Listener
handler proxyHandler
}
func (p *proxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
upstream := p.Select()
network := "tcp"
if upstream.Network != "" {
network = upstream.Network
}
address := upstream.Name
d, err := net.Dial(network, address)
if err != nil {
log.Printf("[ERROR] Unable to establish connection to upstream %s://%s: %s", network, address, err)
http.Error(w, fmt.Sprintf("Unable to establish connection to upstream %s://%s: %s", network, address, err), 500)
return
}
hj, ok := w.(http.Hijacker)
if !ok {
log.Printf("[ERROR] Unable to establish connection: no hijacker")
http.Error(w, "Unable to establish connection: no hijacker", 500)
return
}
nc, _, err := hj.Hijack()
if err != nil {
log.Printf("[ERROR] Unable to hijack connection: %s", err)
http.Error(w, fmt.Sprintf("Unable to hijack connection: %s", err), 500)
return
}
defer nc.Close()
defer d.Close()
err = r.Write(d)
if err != nil {
log.Printf("[ERROR] Unable to copy connection to upstream %s://%s: %s", network, address, err)
http.Error(w, fmt.Sprintf("Unable to copy connection to upstream %s://%s: %s", network, address, err), 500)
return
}
errChan := make(chan error, 2)
cp := func(dst io.Writer, src io.Reader) {
_, err := io.Copy(dst, src)
errChan <- err
}
go cp(d, nc)
go cp(nc, d)
<-errChan
}
func (p *apiProxy) Run() {
p.handler.Start()
p.Serve(p.listener)
}
func (p *apiProxy) Stop() {
p.handler.Stop()
p.listener.Close()
}
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