improve readme

internal/proxy/sse.go

@@ -0,0 +1,34 @@
+package proxy
+
+import (
+	"context"
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"time"
+)
+
+// HandleSSE sets up a go-routine to wait for context cancellation
+// and flushes the response if possible.
+func HandleSSE(w http.ResponseWriter, r *http.Request, rp *httputil.ReverseProxy) {
+	ctx := r.Context()
+	done := make(chan struct{})
+
+	go func() {
+		<-ctx.Done()
+		log.Printf("INFO: SSE connection closed from %s (path: %s)", r.RemoteAddr, r.URL.Path)
+		close(done)
+	}()
+
+	rp.ServeHTTP(w, r)
+	if f, ok := w.(http.Flusher); ok {
+		f.Flush()
+	}
+
+	<-done
+}
+
+// NewShutdownContext is a little helper to gracefully shut down
+func NewShutdownContext(timeout time.Duration) (context.Context, context.CancelFunc) {
+	return context.WithTimeout(context.Background(), timeout)
+}