v0.4.1

internal/web/server.go

@@ -5,13 +5,13 @@ import (
 	"crypto/sha256"
 	"embed"
 	"encoding/hex"
+	"encoding/json"
 	"fmt"
 	"html/template"
 	"log"
 	"net"
 	"net/http"
 	"net/url"
-	"os"
 	"path/filepath"
 	"regexp"
 	"strconv"
@@ -111,7 +111,7 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("GET /{$}", func(w http.ResponseWriter, r *http.Request) { http.Redirect(w, r, "/stats", http.StatusFound) })
 	mux.HandleFunc("GET /stats", s.stats)
 	mux.HandleFunc("GET /stats/live", s.statsLive)
-	mux.HandleFunc("GET /graph/{file}", s.graph)
+	mux.HandleFunc("GET /stats/graph/{key}", s.graphData)
 	mux.HandleFunc("GET /channel", s.channel)
 	mux.HandleFunc("GET /embed/channel", s.channel)
 	mux.HandleFunc("POST /channel/verify/start", s.verifyStart)
@@ -250,43 +250,26 @@ func (s *Server) asset(w http.ResponseWriter, r *http.Request) {
 	_, _ = w.Write(data)
 }
 
-func (s *Server) graph(w http.ResponseWriter, r *http.Request) {
+func (s *Server) graphData(w http.ResponseWriter, r *http.Request) {
 	ip := s.clientIP(r).String()
-	// Graph PNGs are cheap to serve: rrd.Manager.Graph caches each
-	// key+theme render on disk for ~55s, so most hits here are a plain
-	// file read, not an rrdtool invocation. One page view alone can
-	// legitimately touch this 6 ranges x 2 themes (lightbox open, theme
-	// toggle) times, before counting multiple tabs or several visitors
-	// sharing one IP (same household/NAT) -- see README "Rate limiting"
-	// for tuning RATE_LIMIT_GRAPH if this still trips in practice.
+	// Each hit here is one rrdtool fetch returning a few hundred small
+	// JSON numbers read straight from the local RRD file -- cheap, so
+	// the limit mainly exists to stop outright abuse. See README "Rate
+	// limiting" for tuning RATE_LIMIT_GRAPH.
 	if s.cfg.RateLimitEnabled && !s.limit.allow("graph|"+ip, s.cfg.RateLimitGraph, time.Minute) {
 		s.tooMany(w)
 		return
 	}
 	ctx, cancel := context.WithTimeout(r.Context(), 8*time.Second)
 	defer cancel()
-	file := r.PathValue("file")
-	if !strings.HasSuffix(file, ".png") {
-		http.NotFound(w, r)
-		return
-	}
-	key := strings.TrimSuffix(file, ".png")
-	theme := "dark"
-	if strings.HasSuffix(key, "-light") {
-		theme = "light"
-		key = strings.TrimSuffix(key, "-light")
-	}
-	if key == "" || strings.Contains(key, "/") {
-		http.NotFound(w, r)
-		return
-	}
-	p, err := s.rrd.Graph(ctx, key, theme)
+	data, err := s.rrd.Fetch(ctx, r.PathValue("key"))
 	if err != nil {
-		http.Error(w, "graph unavailable", http.StatusServiceUnavailable)
+		http.Error(w, "graph data unavailable", http.StatusServiceUnavailable)
 		return
 	}
-	w.Header().Set("Cache-Control", "public, max-age=60")
-	http.ServeFile(w, r, p)
+	w.Header().Set("Cache-Control", "no-store")
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	_ = json.NewEncoder(w).Encode(data)
 }
 
 func (s *Server) channel(w http.ResponseWriter, r *http.Request) {
@@ -579,5 +562,3 @@ func (s *Server) render(w http.ResponseWriter, name string, data any) {
 		log.Printf("template error: %v", err)
 	}
 }
-
-func EnsureGraphDir(path string) error { return os.MkdirAll(filepath.Clean(path), 0750) }