initial import from /x/ monorepo

Signed-off-by: Xe Iaso <me@xeiaso.net>

internal/headers.go

@@ -0,0 +1,20 @@
+package internal
+
+import (
+	"net/http"
+
+	"github.com/TecharoHQ/anubis"
+)
+
+// UnchangingCache sets the Cache-Control header to cache a response for 1 year if
+// and only if the application is compiled in "release" mode by Docker.
+func UnchangingCache(h http.Handler) http.Handler {
+	if anubis.Version == "devel" {
+		return h
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Cache-Control", "public, max-age=31536000")
+		h.ServeHTTP(w, r)
+	})
+}