Merge pull request 'use direct media for discord' (#102) from use-direct-media into main

Reviewed-on: #102

config/services/matrix-media-repo.nix

@@ -182,6 +182,31 @@ in {
     logFormat = pkgs.lib.mkForce "";
     extraConfig = ''
       import baseConfig
+      handle /_matrix/media/*/download/example.com/discord_* {
+        header Access-Control-Allow-Origin *
+        # Remove path prefix
+        uri path_regexp ^/_matrix/media/.+/download/example\.com/discord_ /
+        # The mxc patterns use | instead of /, so replace it first turning it into attachments/1234/5678/filename.png
+        uri replace "%7C" /
+        reverse_proxy {
+          # reverse_proxy automatically includes the uri, so no {uri} at the end
+          to https://cdn.discordapp.com
+          # Caddy doesn't set the Host header automatically when reverse proxying
+          # (because usually reverse proxies are local and don't care about Host headers)
+          header_up Host cdn.discordapp.com
+        }
+      }
+      # Do the same for thumbnails, but redirect to media.discordapp.net (which is Discord's thumbnailing server, and happens to use similar width/height params as Matrix)
+      # Alternatively, you can point this at cdn.discordapp.com too. Clients shouldn't mind even if they get a bigger image than they asked for.
+      handle /_matrix/media/*/thumbnail/example.com/discord_* {
+        header Access-Control-Allow-Origin *
+        uri path_regexp ^/_matrix/media/.+/thumbnail/example\.com/discord_ /
+        uri replace "%7C" /
+        reverse_proxy {
+          to https://media.discordapp.net
+          header_up Host media.discordapp.net
+        }
+      }
       handle /_matrix/media/* {
         uri * replace /unstable/fi.mau.msc2246/ /v1/
         reverse_proxy http://localhost:8008 {

config/services/mautrix-discord.nix

@@ -41,6 +41,7 @@
             missed.channel = -1;
           };
         };
+        media_patterns.enabled = true;
         encryption = {
           allow = true;
           appservice = true;