From cb4c29f1d70b0463e9af7808c83064ac3164c6c1 Mon Sep 17 00:00:00 2001
From: Moritz 'e1mo' Fromm <git@e1mo.de>
Date: Thu, 13 Apr 2023 13:47:05 +0200
Subject: [PATCH] Deliver images in alternative formats

If the browser supports webp/avif images, nginx checks if any file with
the same name but the other formats extension is available.
---
 services/website.nix | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/services/website.nix b/services/website.nix
index 9c69cc7..16c8a69 100644
--- a/services/website.nix
+++ b/services/website.nix
@@ -23,14 +23,33 @@ in {
     recommendedProxySettings = true;
     recommendedTlsSettings = true;
 
+    commonHttpConfig = ''
+      map $http_accept $webp_suffix {
+        default "";
+        "~*webp" ".webp";
+      }
+      map $http_accept $avif_suffix {
+        default "";
+        "~*avif" ".avif";
+      }
+    '';
+
     virtualHosts.${baseDomain} = {
       default = true;
       enableACME = true;
       forceSSL = true;
       serverAliases = [ "www.${baseDomain}" ];
-      # TODO: Change this to be deployed by some sort of CI + rsync so we don't need to always update the package version
-      locations."/".root = webroot;
-      locations."/.well-known/matrix/".alias =  matrixWellKnownDir + "/";
+      root = webroot;
+      locations = {
+        "~* ^(/images/.+)\\.(png|jpe?g)$".extraConfig = ''
+          set $base $1;
+          add_header Vary Accept;
+          expires 7d;
+          add_header Cache-Control "must-revalidate, s-maxage=86400";
+          try_files $request_uri$avif_suffix $base$avif_suffix $request_uri$webp_suffix $base$webp_suffix $request_uri =404;
+        '';
+        "/.well-known/matrix/".alias =  matrixWellKnownDir + "/";
+      };
     };
   };