/
engine.go
81 lines (71 loc) · 1.46 KB
/
engine.go
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package main
import (
"flag"
"fmt"
"io"
"log"
"net"
"net/http"
"net/http/httputil"
"os"
)
var (
port string
socketPath string
ip string
)
func init() {
flag.StringVar(&port, "p", "", "port to serve on")
flag.StringVar(&socketPath, "s", "", "unix socket to proxy requests")
flag.StringVar(&ip, "i", "", "ip to listen on")
flag.Parse()
}
func writeError(err error) {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
func copyHeader(dst, src http.Header) {
for k, vv := range src {
for _, v := range vv {
dst.Add(k, v)
}
}
}
// Proxy request from the http server to docker's
// unix socket
func proxy(w http.ResponseWriter, r *http.Request) {
conn, err := net.Dial("unix", socketPath)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
log.Println(err)
return
}
c := httputil.NewClientConn(conn, nil)
defer c.Close()
res, err := c.Do(r)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
log.Println(err)
return
}
defer res.Body.Close()
copyHeader(w.Header(), res.Header)
if _, err := io.Copy(w, res.Body); err != nil {
log.Println(err)
}
}
func main() {
var err error
if port == "" {
err = fmt.Errorf("Please provide a port to serve on")
} else if socketPath == "" {
err = fmt.Errorf("Please provide a socket to proxy to")
}
if err != nil {
writeError(err)
}
http.HandleFunc("/", proxy)
if err := http.ListenAndServe(fmt.Sprintf("%s:%s", ip, port), nil); err != nil {
writeError(err)
}
}