Merge branch 'main' of git.mstar.dev:mstar/goutils

I didn't actually write the found ip to the logging stack (or whatever
zerolog uses). This is now fixed

http/sse.go

@@ -0,0 +1,37 @@
+package webutils
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+var (
+	ErrWriterNotFlushable = errors.New("response writer not flushable")
+)
+
+// SseWriter provides a simple implementation for sending data via Server Side Events
+// to the client. The function runs until the dataStream channel is closed.
+// The ResponseWriter must not be used after calling this function
+//
+// Inspired by and partially copied from https://medium.com/@rian.eka.cahya/server-sent-event-sse-with-go-10592d9c2aa1
+func SseWriter(w http.ResponseWriter, dataStream chan []byte) error {
+	w.Header().Set("Access-Control-Expose-Headers", "Content-Type")
+
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+
+	flusher, ok := w.(http.Flusher)
+	if !ok {
+		return ErrWriterNotFlushable
+	}
+	for data := range dataStream {
+		_, err := fmt.Fprintf(w, "%s\n\n", string(data))
+		if err != nil {
+			return err
+		}
+		flusher.Flush()
+	}
+	return nil
+}

http/zerolog.go

@@ -45,7 +45,7 @@ func BuildLoggingMiddleware(
 				}
 				logger.Send()
 			}),
-			hlog.RemoteAddrHandler("ip"),
+			RealIpAppenderMiddleware("ip"),
 			hlog.UserAgentHandler("user_agent"),
 			hlog.RefererHandler("referer"),
 			hlog.RequestIDHandler("req_id", "Request-Id"),
@@ -68,9 +68,33 @@ func LoggingMiddleware(handler http.Handler) http.Handler {
 				Dur("duration", duration).
 				Send()
 		}),
-		hlog.RemoteAddrHandler("ip"),
+		RealIpAppenderMiddleware("ip"),
 		hlog.UserAgentHandler("user_agent"),
 		hlog.RefererHandler("referer"),
 		hlog.RequestIDHandler("req_id", "Request-Id"),
 	)
 }
+
+// hlog.RemoteAddrHandler except fixed to check the X-Real-Ip and X-Forwarded-For
+// headers first for the IP instead of relying on RemoteAddr
+// (which would only return the last proxy's address instead of the caller's)
+func RealIpAppenderMiddleware(fieldKey string) func(handler http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			IPAddress := r.Header.Get("X-Real-Ip")
+			if IPAddress == "" {
+				IPAddress = r.Header.Get("X-Forwarded-For")
+			}
+			if IPAddress == "" {
+				IPAddress = r.RemoteAddr
+			}
+			if IPAddress != "" {
+				log := zerolog.Ctx(r.Context())
+				log.UpdateContext(func(c zerolog.Context) zerolog.Context {
+					return c.Str(fieldKey, IPAddress)
+				})
+			}
+			next.ServeHTTP(w, r)
+		})
+	}
+}