Added most basic auth

internal/server/middleware.go

@@ -0,0 +1,24 @@
+package server
+
+import (
+	"net/http"
+)
+
+func (s *Server) Auth(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		cookie, err := r.Cookie("auth")
+		if err != nil {
+			if r.URL.Path == "/login" || r.URL.Path == "/login/" {
+				next.ServeHTTP(w, r)
+				return
+			}
+			http.Redirect(w, r, "/login", http.StatusFound)
+			return
+		}
+		if cookie.Value == s.secret {
+			next.ServeHTTP(w, r)
+		} else {
+			http.Redirect(w, r, "/login", http.StatusFound)
+		}
+	})
+}