feat: caching headers

internal/server/static.go

@@ -1,9 +1,11 @@
 package server
 
 import (
+	"fmt"
 	"io/fs"
 	"log/slog"
 	"net/http"
+	"time"
 
 	"git.schreifuchs.ch/schreifuchs/schreifuchs.ch/web"
 )
@@ -13,7 +15,7 @@ func registerStatic(mux *http.ServeMux) {
 	fileSystem := web.GetStaticFS()
 
 	// we still use go's fileServer to avoid unnecessary implementation
-	fileServer := http.FileServer(http.FS(fileSystem))
+	fileServer := cacheMiddleware(time.Hour * 24)(http.FileServer(http.FS(fileSystem)))
 
 	err := fs.WalkDir(fileSystem, ".", func(path string, d fs.DirEntry, err error) error {
 		if err != nil {
@@ -36,3 +38,13 @@ func registerStatic(mux *http.ServeMux) {
 		panic(err)
 	}
 }
+
+// cacheMiddleware adds Cache-Control headers to the response.
+func cacheMiddleware(maxAge time.Duration) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Cache-Control", fmt.Sprintf("public, max-age=%.0f", maxAge.Seconds()))
+			next.ServeHTTP(w, r)
+		})
+	}
+}