From db6628d1a532cf54a1e1a21d2dc6644a73d643f7 Mon Sep 17 00:00:00 2001
From: Lucas Roesler <roesler.lucas@gmail.com>
Date: Sat, 22 Jun 2019 21:30:40 +0200
Subject: [PATCH] Remove Hyjacker log handler

**What**
- Remove the hyjacker based logs handler implementation because it is
not needed

Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>
---
 gateway/handlers/logs.go | 115 ---------------------------------------
 1 file changed, 115 deletions(-)

diff --git a/gateway/handlers/logs.go b/gateway/handlers/logs.go
index d0a6e5fa..360eaf51 100644
--- a/gateway/handlers/logs.go
+++ b/gateway/handlers/logs.go
@@ -4,12 +4,10 @@ import (
 	"context"
 	"io"
 	"log"
-	"net"
 	"net/http"
 	"net/url"
 	"os"
 	"strings"
-	"time"
 )
 
 const crlf = "\r\n"
@@ -82,93 +80,6 @@ func NewLogHandlerFunc(logProvider url.URL) http.HandlerFunc {
 	}
 }
 
-// NewHijackLogHandlerFunc creates and http HandlerFunc from the supplied log Requestor.
-// This remains in the package for reference purposes, providers should instead use NewLogHandlerFunc
-func NewHijackLogHandlerFunc(logProvider url.URL) http.HandlerFunc {
-
-	writeRequestURI := false
-	if _, exists := os.LookupEnv("write_request_uri"); exists {
-		writeRequestURI = exists
-	}
-
-	upstreamLogProviderBase := strings.TrimSuffix(logProvider.String(), "/")
-
-	return func(w http.ResponseWriter, r *http.Request) {
-		ctx := r.Context()
-		if r.Body != nil {
-			defer r.Body.Close()
-		}
-
-		logRequest := buildUpstreamRequest(r, upstreamLogProviderBase, upstreamLogsEndpoint)
-		if logRequest.Body != nil {
-			defer logRequest.Body.Close()
-		}
-
-		hijacker, ok := w.(http.Hijacker)
-		if !ok {
-			log.Println("LogProxy: response is not a Hijacker, required for streaming response")
-			http.NotFound(w, r)
-			return
-		}
-
-		clientConn, buf, err := hijacker.Hijack()
-		if err != nil {
-			log.Println("LogProxy: failed to hijack connection for streaming response")
-			return
-		}
-
-		defer clientConn.Close()
-		// A zero value for t means Write will not time out, allowing us to stream the logs while
-		// following even if there is a large gap in logs
-		clientConn.SetWriteDeadline(time.Time{})
-		// flush the headers and the initial 200 status code to the client
-		buf.Flush()
-
-		if writeRequestURI {
-			log.Printf("LogProxy: proxying request to %s %s\n", logRequest.Host, logRequest.URL.String())
-		}
-
-		ctx, cancel := context.WithCancel(ctx)
-		logRequest = logRequest.WithContext(ctx)
-		defer cancel()
-
-		logResp, err := http.DefaultTransport.RoundTrip(logRequest)
-		if err != nil {
-			log.Printf("LogProxy: forwarding request failed: %s\n", err.Error())
-			buf.WriteString("HTTP/1.1 500 Server Error" + crlf)
-			buf.Flush()
-			return
-		}
-		// Body is always closeable if err is nil
-		defer logResp.Body.Close()
-
-		// write response headers directly to the buffer per RFC 2616
-		// https://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html
-		buf.WriteString("HTTP/1.1 " + logResp.Status + crlf)
-		logResp.Header.Write(buf)
-		buf.WriteString(crlf)
-		buf.Flush()
-
-		// watch for connection closures and stream data
-		// connections and contexts should have cancel methods deferred already
-		select {
-		case err := <-copyNotify(buf, logResp.Body):
-			if err != nil {
-				log.Printf("LogProxy: error while copy: %s", err.Error())
-				return
-			}
-			logResp.Trailer.Write(buf)
-		case err := <-closeNotify(ctx, clientConn):
-			if err != nil {
-				log.Printf("LogProxy: client connection closed: %s", err.Error())
-			}
-			return
-		}
-
-		return
-	}
-}
-
 type writerFlusher interface {
 	io.Writer
 	http.Flusher
@@ -197,29 +108,3 @@ func copyNotify(destination io.Writer, source io.Reader) <-chan error {
 	}()
 	return done
 }
-
-// closeNotify will watch the connection and notify when then connection is closed
-func closeNotify(ctx context.Context, c net.Conn) <-chan error {
-	notify := make(chan error, 1)
-
-	go func() {
-		buf := make([]byte, 1)
-		// blocks until non-zero read or error.  From the fd.Read docs:
-		// If the caller wanted a zero byte read, return immediately
-		// without trying (but after acquiring the readLock).
-		// Otherwise syscall.Read returns 0, nil which looks like
-		// io.EOF.
-		// It is important that `buf` is allocated a non-zero size
-		n, err := c.Read(buf)
-		if err != nil {
-			log.Printf("LogProxy: test connection: %s\n", err)
-			notify <- err
-			return
-		}
-		if n > 0 {
-			log.Printf("LogProxy: unexpected data: %s\n", buf[:n])
-			return
-		}
-	}()
-	return notify
-}