F errorlog log wrapper (#89)

* catch error log of http and reverse proxy handler, so logging ends up in the log instead of stderr

* update change log

* better description

* add proper comments

CHANGELOG.md

@@ -15,6 +15,7 @@ Bug:
 Change:
  * Removed manual websocket implementation for httputil's reverse proxy. it now supports websockets in the main branch
  * DNS forwarder library replaced with one that correctly resolves cnames recursively
+ * Error logging of the http/reverseproxy server is now logged in the log file instead of stderr
 
 ## 0.14.4
 Feature:

pkg/logging/log-logger.go

@@ -0,0 +1,30 @@
+package logging
+
+import (
+ stdlog "log"
+)
+
+// StandardLogWriterInterface is an interface to wrap log.Logger
+type StandardLogWriterInterface interface {
+ Write(p []byte) (n int, err error)
+}
+
+// StandardLogWrite implements StandardLogWriterInterface
+type StandardLogWrite struct {
+ //buf bytes.Buffer
+ name string
+}
+
+// Write is the write handler for StandardLog
+func (s StandardLogWrite) Write(p []byte) (n int, err error) {
+ str := string(p)
+ For(s.name).Warn(str)
+ return len(p), nil
+}
+
+// StandardLog returns a log.Logger wrapper
+func StandardLog(name string) *stdlog.Logger {
+ w := StandardLogWrite{name: name}
+ std := stdlog.New(w, "", stdlog.Lshortfile)
+ return std
+}

pkg/logging/log-logger_test.go

@@ -0,0 +1,9 @@
+package logging
+
+import "testing"
+
+func TestStandardLogger(t *testing.T) {
+ Configure("stdout", "debug")
+ l := StandardLog("test/log")
+ l.Print("log entry\n")
+}

pkg/proxy/proxy_http.go

@@ -549,6 +549,7 @@ func (l *Listener) NewHTTPProxy() *httputil.ReverseProxy {
  Transport: transport,
  ModifyResponse: modifyresponse,
  FlushInterval: 250 * time.Millisecond, // good for streams adn server-sent events
+ ErrorLog: logging.StandardLog("httpproxy/reverseproxy"),
 
  // ErrorLog: logrus not supported as logging until v2 => https://github.com/golang/go/issues/21082
  }

pkg/proxy/proxy_listener.go

@@ -104,6 +104,7 @@ func (l *Listener) Start() {
  WriteTimeout: time.Duration(l.WriteTimeout) * time.Second,
  Addr: fmt.Sprintf("%s:%d", l.IP, l.Port),
  Handler: proxy,
+ ErrorLog: logging.StandardLog("listener/http"),
  }
 
  listener, err = net.Listen("tcp", httpsrv.Addr)
@@ -139,6 +140,7 @@ func (l *Listener) Start() {
  Addr: fmt.Sprintf("%s:%d", l.IP, l.Port),
  Handler: proxy,
  TLSConfig: l.TLSConfig,
+ ErrorLog: logging.StandardLog("listener/https"),
  //TLSNextProto: make(map[string]func(*http.Server, *tls.Conn, http.Handler), 0),
  }